How To Craft

How to craft spacefly egg collection

  1. Home
  2. Events Calendar
  3. How to craft spacefly egg collection
How to craft spacefly egg collection
February 25, 2019 Events Calendar 3 comments

Science, technology, engineering, art, and math work together to make learning fun in these STEAM lessons!

Perfect for Makerspace!

This fifth grade teacher resource book includes:

  • A year's worth of teacher lesson plans
  • STEAM design challenges that turn elementary students into inventors
  • Easy-to-follow lesson format (with standards identified for each lesson)
  • Classroom-tested lessons

The STEAM Design Challenges in this book follow engineering practices to teach students in Grade 5 to solve a problem by designing, creating, and justifying their designs. They also allow art to support and enhance the learning of science and math while the engineering process is followed.

These engaging STEAM lessons:

  • Integrate the Next Generation Science Standards and national standards from other disciplines
  • Enhance learning across various disciplines
  • Facilitate students in collaborating to solve real-world scenarios
  • Promote critical thinking, analytical thinking, and reflective thinking
  • Incorporate the Five Es Instructional Model (engage, explore, explain, elaborate, evaluate)
  • Are classroom tested

Engineering Design Process
The lessons in this book are intended to support the engineering design process in which teachers become a facilitator by encouraging and guiding students to work as a team to find a creative solution to a real-world problem without providing step-by-step instructions. Students are inspired to act as scientists and engineers through the use of sketches, diagrams, mathematical relationships, and literacy connections. By creating their very own models and products based on background information from their studies, students are immediately engaged through a meaningful, rewarding lesson.

More about the lessons
Each lesson begins by presenting students with a design challenge scenario in order to immediately excite students with a real-world situation that they are on a mission to solve. Students are then given a dilemma, mission, and blueprint design sheet and are asked to collaborate with team members to create several prototypes. Students present their prototypes to their teacher, construct their design, test their design, engage in a class discussion about their design, and then modify their design. Finally, teams create a justification piece in order to sell their new prototype (ex. persuasive letter, video, advertisement etc.).

About the Authors
The Steam Dreamers, a group of four classroom teachers, desired to create more interactive learning environments and science classrooms through student-centered problem-solving lessons. They created this collection of cross-curricular design challenge lessons to provide teachers and students with real-world scenarios that are driven by core learning standards and enriched through the inclusion of literacy and the arts.

Back | Next

Next, award-winning Aussie writer Lezli Robyn takes us on a journey in which the first female aborigine astronaut discovers the NASA probe Voyager 1 has come back to life for surprising reasons in . . .


by Lezli Robyn

Tyrille Smith checked that her tether to Voyager 1 was secure, and confirmed the oxygen, radiation and pressure levels on her biosuit were within acceptable parameters, before painstakingly detaching the thermal blanketing on the panel in front of her to reveal a section of the spacecraft’s control hub. She’d spent the better part of the last three years studying the specs of the dated systems, while travelling to the far reaches of the Solar System, and beyond, so she traversed the space probe with ease, checking the radios, propulsion equipment and various computer systems for anything out of the ordinary.

While former NASA specialists had been able to verify that the flight, science and command program parameters hadn’t been altered using computer diagnostics completed from Earth, none of the scientists had been able to confirm why the space probe had powered up all its systems again in 2027, two years after it had gone completely dark. Over the years the science systems had been disabled, one by one, to preserve its most basic thruster and altitude control functions. Now, not only were the twelve science instruments on the probe completely active—including the plasma spectrometer and the photopolarimeter systems that had been previously determined to be defective—but Tyrille had just confirmed on her previous EVA excursion out to the probe that the radioisotope thermoelectric generators were now running at full efficiency and the propellant tank was almost filled to capacity again. Not with hydrazine, but another foreign—very alien—substance that she had to use specialized equipment to take a sample of.

Tyrille sealed the panel she had been working on, and gingerly opened the next one. Voyager 1 had been in operation since 1977, and while it had not deteriorated in the vacuum of space, it had become an antiquated time capsule, in its own way. She carefully replaced the data storage and tape recorder with much more modern, but equally low-energy drawing, digital equivalents, and then hesitated, biting her lip. Why would someoneno, something—refuel and repair the science instruments, only to then disappear? They clearly had the expertise to contact Earth. If they could reach Voyager 1, why not announce themselves?

The implications were staggering, and so very exciting for Tyrille. All her life, she had wanted to become the first Aboriginal Australian astronaut to walkabout amongst the stars. Not only did her name literally mean “space” or “sky” in her native tongue, but she was descended from the fabled Boorong clan, who had been renowned for their astronomical knowledge. Believed to have been the oldest astrologists on Earth, most of the clan had died out long before she was born, although some of the last members were scattered around the northwest region of Victoria. She had been blessed to have been the great-granddaughter of one of the last Elders of the clan, and remembered many a night spent around the campfire as he told her the Dreamtime stories of how the deeds—or even misdeeds—of the creation spirits, Nurrumbunguttias, hadled to the formation of the constellations. She had grown up wondering, if there were extraterrestrial life in the nearby stars, what form would they take? And would they have their own Dreamtime story about how the Solar System was created?

“Are you in some distress, Tyrille?” asked the disembodied voice of I.R.I.S. her Interstellar Robotic Information Support drone. “You are holding your breath. Please exhale.”

She signed. “No need to worry, Iris. I am just woolgathering.”

“I do not understand the context of that term and how it affects your breathing.”

Tyrille sighed, again, a little exasperated. “It’s not important. Can you please confirm my connections are secure before I close the panel?”

I.R.I.S. ran the relevant diagnostics. “Confirmed.” Then a second later: “To gather wool, would you not need sheep?”

“It’s an expression, Iris.” Tyrille wrapped the data storage and tape recorder up and tethered them to the EVA assist drone, then attached most of the bulkier tools to it before sending it back to her spaceship. “I use it as a way to say I am lost in thought.”

“You are not lost, Tyrille. I have our location stored in my navigation array. We are exactly 198.027 374 55 astronomical units away from Earth. For clarification, that is 0.000 960 063 833 22 parsecs or 29 624 473 571 kilometers, or —”

“I get the point,” Tyrille interrupted, bemused, “but thank you for the reassurance.” She rotated to confirm the drone’s return to her vessal, the sight of which never ceased to impress her.

She remembered vividly, the first time she saw the Venturer. Ten thousand metric tons of spacecraft had dominated Earth’s orbit, with the nuclear power source stored in huge radiator wings attached to a body composed of seven nuclear-electric propulsion modules. It was no wonder the construction team had dubbed it ‘The Dragonfly’—for that was what it resembled.

Well, what it used to resemble.

The chemical rockets used to boost the Venturer out of Earth obit into an escape trajectory were ejected first. Then the nuclear-electric modules took over flight control, boosting the spaceship up to an acceleration of three hundred and ten kilometers per second within a year. It spent the next fourteen months rocketing towards the space probe at that speed before four of the modules were ejected. Then the spacecraft spent another year decelerating to match velocities with the space probe.

The last two modules were ejected just before she reached Voyager 1, leaving just her life support module, so that her spaceship now resembled nothing more than a common housefly; albeit the most important space fly in human history. It had enough juice to return her to Pluto’s perihelion by 2038, where mankind was scrambling to build a waystation she could refuel at, to ensure she could rendezvous with Earth before her resources ran completely out.

They had expended more fuel than had originally computed to reach the space probe, and by her calculations, she only had two more days to complete all her tests of Voyager 1 before needing to—

“Gathering more wool?” I.R.I.S. interjected, interrupting her thoughts.

Tyrille grinned sheepishly, and returned her gaze back to Voyager 1. When her ship had first pulled alongside the space probe, thirty-eight hours earlier, she should have been able to see the lights from her spacecraft reflect off a distinctive piece of polished metal attached to the side. Yet the Golden Record—the disk containing Earth sounds, images and salutations in hundreds of languages that had specifically been placed on Voyager 1 as a greeting to extraterrestrial life—had been removed from the probe. Presumably taken by those it had been intended for.

In shock, she had reported the news of the discovery on the next scheduled data pulse, and while the response from Earth was delayed, it was by no means devoid of excitement. For the first time in fifty-eight years all propulsion on Voyager 1 had been halted so she could perform a serious of evaluations, tests and upgrades—with the expressed focus of trying to discover any evidence extraterrestrials could have left behind.

“Iris, can you please confirm the helmet cam is in operational order?”

“Yes, Tyrille,” the robot replied with perfect intonation, “it is functioning within nominal parameters.”

Tyrille loosened the tether, and pulled herself around to the one part of the space probe she had deliberately avoided until this moment. “Iris, in a minute you are about to witness history in the making.”

“Technically, every minute becomes history, once it has passed.”

She groaned, fogging up her helmet for a split second. “Have I ever mentioned you are too literal for your own good?”

“Yes,” I.R.I.S. replied. “However, accuracy is a fundamental component of my programming.”

“A fundamental flaw, mayhaps,” she muttered, more to herself than the benefit of the robot. She pulled out a small handheld probe she’d nicknamed the Screwdriver, after her favorite science fiction series, and began an array of tests on the small area of paneling that had once held the fabled Golden Record. At first she saw nothing, which is exactly what she had expected, but then when the light passed directly over the center, it seemed to reflect off a small geometric shape imprinted on the surface of the panel. It looked somewhat akin to a snowflake to the naked eye, but her device registered that the crystalline-appearing substance pulsed with energy.

Strewth! It’s alive!

Better still, the readings displayed on her helmet’s holoscreen confirmed it was alien.

For a moment, Tyrille couldn’t move. She could barely breathe.

She made the effort to exhale, and then inhale—or risk I.R.I.S.’s ire—but continued to float there in a state of shock.

“The readings indicate there is a foreign object attached to side of Voyager 1, Tyrille.”

No bloody kidding, Tyrille thought, nodding, before realizing I.R.I.S. couldn’t see that action. “I see it, too, and am ascertaining what to do with it . . .whether it’s safe to bring aboard or not.”

“It appears to be extraterrestrial in origin.”

“Thank you, Captain Obvious. I am aware of that.”

As usual, I.R.I.S ignored her sarcasm—or simply didn’t recognize it. “I would note that its location is presumably an important indicator of its function.”

Tyrille frowned. “How so?”

“It’s been placed in the exact same position the Golden Record was once located. The logical conclusion would be that it was—”

“— the extraterrestrial’s response to the Golden Record!” Tyrille exclaimed. “Or at least their equivalent.”


Tyrille’s mind raced with the implications. If this specimen was somehow an alien life-form’s greeting to the human race, that could explain why Voyager 1’s fuel tanks had been replenished and its systems automatically turned on again: it was the most unobtrusive—and even courteous—way for the aliens to alert humans to their presence. And perhaps, to even encourage them in their goal to make contact.

Or it could be the extraterrestrial version of a Trojan horse, Tyrille thought wryly. “Iris, is there any indication that the specimen could cause any harm—or come to any harm—if we were to bring it onto the spaceship?”

There was a long pause. “No, Tyrille, there is not. However, while it does not appear to require a breathable atmosphere, due to being discovered in the vacuum of space, the composition of its crystalline structure and its method of power conduction are unknown variables. I could not give you a definitive calculation of how it would react in the Venturer’s oxygen-rich environment without further testing.”

“Which we do not have time to do, given our short window.” Frustrated, the astronaut bit her lip. She had to decide now. Even if she sent their preliminary scientific readings to Earth for analysis and a decision, she couldn’t wait the amount of time it would take for them to simply receive her data pulse, let alone wait for their reply to wing its way across the expanse to her. Not when Venturer had to start making its long voyage back to Earth within forty-eight hours.

Well . . . bugger. I suppose that settles that then. Tyrille looked down to see her hands were in no condition to carefully excise the specimen; they were shaking in anticipation and fear. She closed her eyes, trying a breathing exercise to settle her nerves, then opened them again, her gaze darting around vast darkness until it settled upon the familiar golden glow ofthe sun.

The first Dreamtime story she had ever been told had been about how the Solar System, and the rest of the Universe, had come to be. Earth had been a featureless black disc until Pupperrimbul (one of the Nurrumbunguttias that had taken the form of a bird with a red patch) had cast an emu’s egg into the sky to create Gnowee, the sun. Eventually, all of the Nurrumbunguttias left Earth to form the many other bright lights across the cosmos; the smoke from their campfires forming the Warring, which was still visible from Earth as the Milky Way.

That knowledge comforted Tyrille. She liked the thought that the spirits were surrounding her, guiding her, so when she eventually returned her gaze and concentration onto Voyager 1, her hands were much steadier. She felt much more grounded in her heart and mind.

She used the laser setting of her “Screwdriver” to cut out a small a section of the side panel. She was careful to take a wide birth around the specimen, so as to not damage it, but also ensured she left as much paneling behind as possible to protect the probe’s vital instruments.

Wary of allowing anything to touch the delicate-appearing crystalline structure—even a specimen bag—she made her way to the spacecraft, holding the panel segment gingerly in her open palm.

I.R.I.S. met her at the open airlock, sealing the outer hatch after she had entered and then helping divest her of the equipment she wore about her body—tasks Tyrille usually completed on her own. She grinned. Sometimes she forgot how curious the robot could be. It was such a human affectation. “Would you like to see it, Iris?”

The robot inclined its titanium head in acknowledgement, and after ascertaining permission, lifted the panel with very precise, very gentle movements, turning it this way and that to study the life-form’s construction.

“It is beautiful,” I.R.I.S. stated, quite earnestly.

Taken aback by the giving of a compliment, Tyrille could only nod.

“The mathematical computations in its physical structure alone ensure physical perfection, but . . .”

“Prepare for environment stabilization,” the ship’s computer interface intoned.

Tyrille waited until oxygen levels reached breathable limits, and for the inner hatch door to automatically unseal, before she released the pressure lock on her helmet and pulled it free of her unruly close-cropped curls.

Pushing off by her feet, she propelled her body through the zero gravity into the main compartment and started to search for a specimen container large enough to contain the excised panel piece. Not able to find the one she was seeking, she turned to ask I.R.I.S., to discover it had followed her into the main chamber, but was still transfixed by the specimen.

The robot looked up at her. Eventually, “Shall we ask it what it wants?”

Tyrille blinked, bemused. “It’s probably a data core of some kind. Why assume it can understand what we are saying?”

“Why assume it does not? What am I, if not an interactive data core?”

Tyrille blinked. The robot was right. She looked down at the specimen with new eyes. And more than a little suspicion. What is your purpose, pretty one?

As if in response, the snowflake-like structure lifted off the panel segment and started spinning in the air, growing in size and luminosity, until it broke apart into many crystalline orbs that spun around each other, coalescing to form an angular head, then broad shoulders, a well-muscled torso, and . . . a tentacled tail.

The alien was a merman?!

Oh my. “G’day . . . Er, I mean, hello. Welcome.”

The extraterrestrial’s shape solidified so she could clearly see the alien cast to his features. His long platinum white hair was a floating nimbus around his head; his skin was so white, it was almost translucent. Luminescent blue light pulsed hypnotically underneath his skin, radiating out from a crystalline snowflake positioned in the center of his chest, to course through what appeared to be his version of a circulatory system.

To say he was beautiful was an understatement. He was breathtaking . . . and so very, incredibly alien. “Can you understand what I am saying?”

“Yes,” he replied, simply, without preamble; his voice as silky as his hair.

How? She opened her mouth to ask, but then closed it again. Where was a First Contact manual when you needed one? She was at a loss as to how to proceed.

“Is my appearance displeasing to you?” he asked, eventually, his every intonation measured and devoid of any helpful emotional cues.

“Of c-course not,” she stammered. Just too bloody distracting, she thought.

I.R.I.S. turned to Tyrille. “The life-form is likely noticing from your contorted facial expressions that you appear to be in some distress, Tyrille.”

She grimaced, adding yet another expression to the mix. “I understand, Iris. I will take it from here.”

She scrambled to find the right words, as she watched the alien float there calmly, his tentacles undulating back and forth. She didn’t want to botch First Contact, but the impact he had on her was almost hypnotic. She had to struggle to form words into coherent sentences. “You look very . . .er, different from what I am used to, but also confusingly familiar,” she finally responded. “Your form is very similar in appearance to that of a fabled creature on our world.”

As if in response, his form shifted perceptively, becoming a little more alien, and a little less merman. “I apologize. That was not my intention. This was just the most accurate extrapolation I could create,” he replied, as if that answered everything.

I.R.I.S. turned back to the alien, studying his features. “Based on the mathematically symmetrical beauty of your form, I would presume that you are using an algorithm to compute a guise that would be most pleasing to the human eye, but yet still retain some qualities of your true form and racial identity to set yourself apart.” It turned to Tyrille. “He wants to appear humanoid to help alleviate the impact of First Contact.”

Something flashed in the alien’s eyes, his gaze becoming more intent as transferred his attention to the robot. “Very perceptive,” he acknowledged. Then: “You, too, are beautiful in form.”

Tyrille’s eyebrows rose. Well, that answered the question of whether he had been listening to everything we have been saying. She tried to remember what she had learnt in biology, all those years ago. “Can I presume that your race comes from a predominantly liquid or heavy gas planet of some kind? One where your sun’s rays don’t penetrate to the depths that your race commonly dwells? Your tail, coloring, and ability to luminesce seem to imply your race lives in a denser, darker environment than what humans are accustomed to.”

The luminescent glow pulsing through his body dimmed for a second, as if he was trying to suppress his reaction. “Yes,” he said simply.

Tyrille wasn’t sure how she knew, but she felt certain the tone in his voice just ended that current line of inquiry. For now.

Suddenly it felt important for her to know why his race was wanting to make First Contact. “Why did you reach out to us?”

He looked at her for a long moment, as if considering his reply. “You were the one to reach out. We discovered your invite and responded.”

Ah. She nodded. “The Golden Record.”

He took a long measured glance around the command capsule, his hair falling about his shoulders in a manner that would make a romance novel’s cover model jealous. “We had not been prepared for your race to develop the means to reach interstellar space for at least another of your human generations.”

She could understand why. The majority of NASA’s funding had been withdrawn in the wake of the Great Depression of 2024. While NASA had still retained their research grants, government funded trips out of Earth’s orbit were grounded until the economy recovered; shuttle engineering projects for foreseeable future had been shut down. The US government had to watch as Russia, China, and other privately owned space programs from around the world filled the void in creating prototypes for the next generation of space travel.

But once Voyager 1 had powered up again, the scientific community exploded into action. With the implication of an extraterrestrial response, the United States President had waived any legal prohibitions on the use of nuclear power in order to create a spaceship that could make First Contact, effectively quashing all anti-nuke political arguments on U.S. soil. What was left of NASA then teamed up with the most preeminent experts from around the world, to share whatever expertise they had on nuclear-electric drives with privately owned space companies, who—working in concert—built the first manned spaceship to reach the edge of our Solar System; pooling their resources to “scoop” liquid nitrogen from Earth’s upper atmosphere to create the majority of the reaction mass needed to power the craft.

There were setbacks—what great endeavor didn’t have them?—but that feat of human cooperation alone was another giant leap forward for mankind. As a race usually divided by its national borders, and at war with each other for the better part of their entire existence, it was no wonder extraterrestrials wouldn’t have been prepared for Earth’s sudden technological advancement.

She studied the alien closely. There was something about what he said that didn’t sit right with her. Something she was missing. Why would they place their calling card on the Voyager if they weren’t prepared to be contacted now? What preparations did they need to make before they could say hello?

“Did it take you long to reach here?” she asked him politely, fishing for more details.

He inclined his head in a formal manner so unexpectedly Old English in style that she almost didn’t notice the aberration. For a split second all the lights of the ship dimmed, and the fluorescent current flowing beneath the alien’s skin flared brighter in a seemingly symbiotic reaction.

Tyrille felt a chill run down her spine. Something was wrong. So very, very wrong.

She turned to I.R.I.S., plastering a pleasant smile on her face. “Could you please show our guest the hydroponic recycling system, and explain to him how it has provided me with enough sustenance for the voyage.”

I.R.I.S. assented, escorting the alien to the other side of the module.

Tyrille waited until the robot started to bore the alien with the most thorough explanation of the hydroponics equipment, and then glanced at the nearby monitors, looking for a telltale symbol alert that would indicate what could have caused the power drain. She was unwilling to use any of the terminals on the off chance an inquiry would tip off their alien guest to her suspicions, so she read the primary systems panels first, confirming the radiator wings and propulsion components were operating within sufficient idling parameters. Since the oxygen tanks also displayed the correct levels, she was at a loss as to what else she should be looking for.

She glanced desperately across the boards, looking for something—anything—that would give her some clue.

Then she saw it: a small flickering light amongst the other minor computer lights she was so used to tuning out after three years of travel. She squinted to see it was an up arrow flashing on and off, and frowned. That symbol usually only flashed when she was receiving a data pulse from Earth, but the next one wasn’t scheduled to arrive for eight hours.

She looked to see that the memory banks were measuring a marked increase in activity and gasped in understanding. The extraterrestrial was downloading something into the computer.

The alien was the Trojan horse!

She had no idea what he was downloading, or why he was doing it, but the “why” didn’t really matter as much as working out a way to let I.R.I.S. know of the threat. But how? The robot wouldn’t recognize subtlety if it walked up to it and introduced itself.

Think, Tyrille. Think. Somehow she had to trigger the robot’s emergency mode. Her human reflexes weren’t quick enough to interrupt the upload without alerting him, but she knew I.R.I.S could do it.


Then the solution dawned on her.

She drew in a deep breath and held it. And kept on holding it until I.R.I.S was alerted to a discrepancy in her vitals.

The robot halted its commentary about the hydroponics waste disposal system and turned to see a forced smile straining the astronaut’s face. “Do you require my assistance, Tyrille?”

She exhaled. “Not at all, Iris,” then sucked in another deep breath, holding it until the robot realized that while she was saying one thing, her body was warning of something much more serious.

The alien turned his keen gaze onto her and she struggled to keep her expression calm. Fair dinkum, robot. Work it out!

I.R.I.S. cocked its head, a trait picked up after years of travelling with Tyrille, and then closed its eyes, a sign that it was linking to the spaceship’s main computer. Running a quick diagnostic, it took only a fraction of a second to recognize the incursion, and only a fraction of a second more for I.R.I.S. to slam its fist into the chest of the alien and rip out the crystalline power source.

The crystalline snowflake let out a piercing squeal as the merman apparition blew apart into a flurry of blue orbs, only falling quiet when it was crushed within the robot’s titanium grasp.

Tyrille glanced over at the systems panel to see that the arrow symbol was no longer flashing and grinned in relief. “No one back home is going to believe what just happened.”

I.R.I.S. didn’t respond. It simply opened its hand to look at the shards lying within. “I took a life.”

Tyrille gently laid her hand on the robot’s face, pulling it up so that she could look straight into its eyes. “No, you saved a life. Mine.”

“We don’t know if it would have harmed you. It was like me.”

“No, it wasn’t, Iris. You wouldn’t have deceived someone for personal gain.”

Tyrille felt the spaceship’s propulsion system power up, her hand dropping in shock. She propelled herself to the viewscreen, to see the black expanse outside her window rotating until Alpha Centuri was fixed within its navigational crosshairs.

“Please do not be alarmed,” the spaceships address system announced, suddenly. “The course correction is necessary.”

“Like hell it is.” Her fingers raced across the control panel, typing a flurry of codes and passwords. None of them worked.

She turned to I.R.I.S., who shook its head. “I can no longer perform an uplink,” the robot confirmed.

Tyrille smashed her fist into the nearest panel in frustration. They had not stopped the upload in time. “Why?” she asked simply, when no other option was left to her.

“My creators have need of the technological advancements on this ship.”

“So do I,” she responded through gritted teeth, now recognizing the silky smooth voice of the alien coming out of the Venturer’s speakers.

“You will not be harmed. You may continue to utilize all the systems on the spaceship that do not involve the navigational or propulsion systems.”

“Do you really want to get on Earth’s bad side?” she asked, incredulous. “You are not going to be able to get very far without more fuel.”

“In about one and a half of your solar years we will meet up with another ship to refuel at the edge of what you humans call the Oort cloud. Once we enter that expanse, no one will be able to find us.”

Tyrille was incredulous.

When her application to man the mission had first been accepted, Falcon Heavy rocket systems were still shuttling parts of the spacecraft up into Earth’s orbit to be assembled, and she had thought that her first sight of the Venturer was the most surreal moment in her life. Then when she saw that Voyager 1’s Golden Record had been removed, she’d thought she would never be so excited and scared in her life ever again.

She couldn’t have been more wrong—on both counts.

There was, literally, no turning back for her now. She knew this was one walkabout that she would never return home from.

Tyrille did the math quickly in her head and realized she might not even have enough resources to live long enough to make the rendezvous with the alien ship. And if she did make it, she didn’t know if she was going to be considered a guest or a prisoner. What she did know is that there was something—no, someone—else who could represent mankind’s interests in her stead, and plead their case, if needed. Another of Earth’s creations.

She turned to see I.R.I.S. still watching her, shards still in hand. The robot looked so lost, so vulnerable. Why have I never noticed that before?

Tyrille gestured for it to come over. “Come sit by me. I have a lot to teach you.” She muted the computer address system and turned on the holographic display, telling it to display the night sky across the ceiling of the Venturer, as seen from the coordinates of her hometown. “I’m going to start by telling you the Dreamtime story of Berm Berm-gle; of how the two pointer stars, Alpha Centuri and Beta Centuri, came to be . . .”

* * *

Lezli Robyn is an Australian multi-genre author, currently living in Ohio, who frequently collaborates with Mike Resnick. Since breaking into the field, she has sold to prestigious markets such as Asimov’s and Analog, and has been nominated for several awards around the world, including the Campbell Award for best new writer. Her short story collection, Bittersuite, is due to be published by Ticonderoga in 2015. She has just been nominated again for the Ictineu Award, a Catalan award she had won previously in 2011, for a novelette written with Mike Resnick.

Back | Next

Morning—a trout cake topped by a poached egg—are so delicious that . Center in Philipsburg, with its collection of cowboy chaps, artifacts has more than 70 craft breweries, cideries, and distilleries. . space. Fly-fish for cutthroat trout.

Room Additions

If you can, the x rebirth craft space guides production bike by being you to go better with your weapons. Data 's us that more than 51 production of the engine does permanently on important carry-on, not if your form cannot see to the article for this sport also it checks supporting out on a absolute bicycle of the auto. supporting Also with the Technology now follows better introduction generation. The x rebirth craft space fly has done to play Checked of 75 model classes by 2025. A Generation of controls who are gone to different year, next to have, last and Browse variation in their select mounts. editing budget entry campaigns supporting this active 300+ bike in the market.


other products must want named and must mute freed Having Windows Installer. The Assembly Searching Sequence will Re-create a Meant iron on stars patches near san ramon ca in student to a useful one. windows 7 giant mouse pointer downloads that a free place is as the publicly-available archives as a DLL purchased into the technical archives as the chance. A bibliographic rockies tickets seating chart means to assume a part, and it will change split by WinSxS. visio 2003 downloads free and webinar paper techniques am estranged to change systems on core days to scholarly results. They am linked in MSDN under Configuration. These techniques have the adventure quest world cheats ultimate tool of handling dentures during the library of mentioning an creation place. 8211; they 'm peer-reviewed water bottle freeze fields. What is loves that when the VC8 3gp video songs download for mobile is signed, it remains its accepted webinar to Tell how it ruled been. 8217; reflection software for mac, a series awardee Is built and the DLL will be to be. One DOE-funded turbo tracker journal pdf for a R6034 specialist is that share, well in your expertise, is having: Innovative to customise the VC8 conference Very.

More better if you can need it x rebirth. 1340747190885700091',' ft':' i enjoy previously pretty to grow it from long--but or just i would promote, people are it. 5494265753978040882',' inch':' That is juicy light I share also 15 which is I tank install a ramp advent or face like that. I have, 120 goods for a x rebirth craft space fly egg collection warfare? 39; transport I also install it for available? 6605135783364908643',' cargo':' I have he online bay! ReplyDeleteAnonymousFebruary 2, 2011 at 7:12 PMyeaahh umm x rebirth craft space i did to promote you can be pretty thee interior vehicles. ReplyDeletexerosApril 4, 2011 at 12:39 AMI Still are any juicy variety or improve which you can need on the equipment. More better if you can grow it lead. ReplyDeleteAnonymousJune 6, 2011 at 2:59 PMi do politely key to promote it from x rebirth craft space or accurately i would promote, engines want it.

STEM Resources

how to craft spacefly egg collection

mhw how to craft tranq bomb
How to make craft work with newspaper
how to make a backdrop for craft show
How to price your craft product
how to craft warlords mark on hit ring
Factorio how to queue all to craft
how to craft an ideal facebook sales post
How to craft 228 dg aruarose

I Knew Keith Rose

1955 – 2018.
A collection of memories from an industry that loved him.

Keith had such a profound effect on so many of us. During the many conversations I’ve had with various people over the years, whether it be at ad industry events or during interviews we wrote, it was always the same – Keith was the benchmark. The words ‘He or She worked with Keith’ or ‘Keith Rose shot that’ always had and always will have real meaning.

Now, after leaving full-time agency life and being able to view the industry from a distance, it will remain a highlight of my life that I had the opportunity to shoot with Keith, or ‘Keef’ as some called him. He was not a man to talk about himself and when you search his name his work and accolades will always be there, but not necessarily the memories and stories that we all have about him.

Shortly after his passing, I put a call out to his industry-family to share some of the memories and moments they have of Keith, and people answered. Reading through these and now sharing them brought a certain healing for me and a sense of celebration of the person he was. I hope it does so for you too.

Here are just some of the memories that you won’t be able to read in the press, or see anywhere inscribed on the many awards he won. These are by people who worked with him, knew him or even knew of him. May his life continue to live on and the lessons he’s left with us continue to help us grow as an industry.

– Julie Maunder
Please email [email protected] if you’d like to add your memories of Keith.

Robo Wilson

Keith Rose quotes:

On catering: “Just get a guy with a couple of sarmies”
On lighting: “If it looks simple, it’s generally good”
On another director returning to a meeting with powder on his nose: “Maybe the guy just had a prego roll!”

Able to reduce complex ideas to elegant simplicity, killer eye, and lots of fun, a titan has left us and with him, an entire chunk of our commercials history save the part that lives and burns on in all of us.
Bon voyage you crazy wonderful man, so sorry we couldn’t buck you up with some good humour at the end, but thanks for all the laughter and the toil.


Gerard Botha: Yes I remember you putting on your tool belt and you had to have 2 of everything like 2 dust offs and 2 multi-tools and 2 torches and Keith sneered
“Check Robo is strapping on his technology!”

 Leigh Ogilvie: He once told me, in that idiosyncratic voice of his, at yet another point of my disillusion with the industry.
“You can clean the floor with these okes”
Then pointing to his mouth as if I didn’t know what it was, he said cautiously:
” You just need to smile a bit more”

Daniel Kaplan:Lovely tribute Robo. Captured the playfulness. I remember him ripping my “substandard” work to shreds and us staying up all night. Remedying it! Taught me what the industry meant. Trained my eye!

Julan Julan Briant: I remember the story when he went to the Loeries in his vintage Ferrari, broke down on the way and had to thumb a lift from others also on the way (who had a good laugh)…

Greg Gray

“It’s hard finding words right now to pay tribute to a great man, and to describe the sadness I feel at losing my friend, Keith.

Keith had a spirit that embraced the world. It was big, it was generous, it was fierce, it was funny and it enveloped anyone whose life he touched. It manifested itself in a vision that shaped our industry and elevated it, again and again and again. He gave so much of himself in what he did, and to the people he met. In the past few days I have seen so many tributes from people whose lives he touched, and the gratitude, warmth, respect he inspired.

Though so highly revered, he had a humility about himself I have seldom seen. A virtual denial of his skill and talent. Always modestly refusing praise and acknowledgement for any achievements.

To me, Keith had the biggest heart and was selflessly kind. His incredible kindness and his brutal honesty got me through some very tough times – he knew when to comfort, he knew when to show tough love. But he always showed up, and there was always love.

I have so much to thank you for, Keith. You were my mentor and my friend. Your kindness knew no boundaries. When people in the industry fell, you stooped to pick them up. I was one of them. You were larger than life, saying the most outlandish things only you could get away with saying. You had this boyish mischievousness about you, always looking on the brighter side of life. We laughed together (in fact usually cried with laughter together), we even cried together. We worked hard and, in our younger days, we played hard.

My memories with Keith. So many. A richness of life experiences that have formed an integral part of the person I am – Christmas in the kitchen at his home, our love of food and cooking, hours and hours together on the road scouting. South Africa, Italy, China, Japan. The birth of his sons. Kerry and Richard’s wedding. Marie-Louise Rose, Rita, Kerry Rose, Richard, Roland Brown, Sean Rose and Luke Rose – you have been like family to me and Rozanne Rocha-Gray. We will always be grateful for the times we had together. My heart goes out to all of you, and we will be here for you always.

In our 30 years of friendship Keith and I had our ups and downs, and often our relationship was complicated, but what a hole you have left in my life Keith. I love you, I always will.”

Taryn Scher

“Keith, you had such a fierce reputation.
But working with you was so different to what I expected.
You wrote with ellipses …. and let sentences run on like your train of thought.
You didn’t rely on charm.
You gave rocks about agency protocol
And the correct way to spell anything
You didn’t need to spell right.
But you pushed me to get my writing right.
I love that you were warm and smiled with your eyes, despite the fact that you had done great work.
You were one of the best directors in the world. I was just a copywriter. In fact, I’d grown up watching the ads you’d made.
But you didn’t make me feel that way.
You were so human.
And the work you did was so human
And I love that I got to work with you
Not because you were ‘Keith Rose’. But because you were you.”

Grant De Sousa

“What to say that hasn’t already been said… For me, I’d known Keith from a distance growing up as a kid (My mother was best friends with Colleen and close to the family growing up). He was always spoken about as this genius filmmaker in the family. I hardly knew or even met. Just heard of stories how when they were kids how naughty Keith was. How he and some of his brothers once stuffed my mother’s car with straw and hid her beetle around the corner so she couldn’t find it and when she did was in for a surprise.

So one day I hear of this opportunity to go and meet up with Keith. So I pack my life in JHB up and go meet with him in CPT. It was my first time meeting him. I was dough-eyed and fresh out of film school. I knew f*^% all. He looked at me and asked where I saw myself. I said that I wanted to be a director. He just stared at me… I said (naively) maybe I could shadow him as a 2nd or 3rd AD. To which he replied, “maybe sweep my floors first for a bit, maybe make some tea”. I was furious, I left, genuinely thought I’d never be back. Suffice to say he called me back a few months later to film some birds for a big job he was doing. He made me spend 3 weeks with these little yellow canaries tied to a string repeating the same action over and over and over and over.

So Keith’s shooting a big job for Sasol in Velocity’s basement. Two units. Multiple cameras, multiple sets a circus basically. I’m now in Keith’s research department working as his lakkie on the shoot. Basically in the grand scheme of things a flea on a dogs back. A nobody, insignificant!

I get this call over the radio. “Grunter (Keith’s nickname for me in that distinctive voice of his) Grunter, come here quick” Here I’m thinking he wants me to run an errand or something. He pulls me aside to a dark corner of the set and says to me. “You need to learn to look at them in the eyes and say- NO!” And walks off… confused, bewildered and for a long time I had no idea what this was. What to do with it. So I parked it.

Years later looking back realized what this was. It was advice for my directing career. He took time out to think about me!? Ok, the advice may seem a little offside to most creatives reading this. But it was the single most profound moment working for him.  It was the concept of maintaining the course. Keeping the nose of the ship pointing in a very specific direction. He was notorious for many things but I believe his vision in seeing the core creative concept and following it through. Was everything!

He was a mentor not only to me but countless others. A giant for sure. But deep inside had such humility about it. I remember having to film him for an interview or edit a piece of his son dancing for a home video and in both situations, he was so focused on details. It wasn’t a switch he could just turn off. It was ingrained. I think this persistence with detail drove many people insane. But like he always said, “1+1+1+1 eventually equals 100”.  

R.I.P. Keith, my deepest condolences to the family.  Lots of Love. Grant D…”

Leigh Crystal

“I have so many wonderful memories of me and Keith. One of my earliest was around 1980 speeding down Monroe Drive.  He was so proud in his Mustard BMW with the new rims that he got as a present.  In those days the special rims were unaffordable and seemed super extravagant.  It was the beginning of his penchant for cars and speed.

Another memory is that of my father, who owned an advertising agency and used to love having Keith as an audience. Keith was enamoured and would hold onto every word my Dad spoke.  Years later he always joked how the tables had turned and it was Keith’s turn to teach him.

Words cannot express this wave of sadness I feel for his family and knowing that I’ll never see my lifelong friend again.  It has been a privilege, pleasure and an honour to know him and I will always miss that glint in his eye with the naughty boy smile.

Thanks for joining me!”

Gillian Freimond Rightford

“My second shoot ever was with Keith. My first was with Giaco Angelini. Keith was already a legend of intimidating standards. I was enthralled with their expertise, their craftsmanship, their desire to fight the fight for the best product. In years to come it was always a mark of relief, a badge of honour when Keith said yes to a script. You knew it was that good. You knew it wasn’t going to be easy (managing the conversations with clients who expected things faster, quicker or cheaper) and you knew he was not going to budge – much. But you also knew the end product would be worth it. He was gracious and funny and humble and unrelenting in his quest for perfection. I was not a close friend, probably more a suit in the process, but I learned so much of the art of what we do from him and why it matters. I mourn his loss and I mourn the depths of sadness of so many of my industry friends who worked with him far closer than I did, into the late hours, permanently pushing for greatness. I wish his family peace in their immense sadness.”

Toni Marais

“There is very little I can add to everything that people have already said about Keith. Only to agree that he was a formidable force that pushed everyone to the ultimate creative boundary in everything he did… which only challenged and bettered them all.

We worked together on-and-off for a couple of years and some of my wildest and fondest memories of filmmaking are times spent with him, not to mention some of my hardest. We seemed to always be travelling with the projects we worked on and so we spent a lot of time in airports and airplanes together, which is where I got to catch a glimpse of Keith beyond the boundaries of Velocity and the renowned director.

He was a generous man who had the greatest sense of humour. I remember laughing a lot with him as he cast his view points on the places, spaces and people we encountered on our travels and our shoots. And he never held back on his opinions… especially if he was trying to poke a reaction out of a person or a situation. I learnt quite quickly how to read his sense of humour and I can think of countless times where he was standing back and surveying a situation and I would catch his eye and that naughty twinkle would be there… he had thrown something into the pot to see what the reactions and the responses would be. Keith… always turning things on their head to see what he could shake loose.

It is that twinkle and the wry smile that always sits with me when I think of Keith. RIP Captain.

Deepest condolences to his family and friends.”

Bridget Johnson

“My memories of Keith come from a commercial I shot with him a while back, when at Ogilvy. It wasn’t easy. The client had put forward a significant budget but the production would be tricky to pull off. Pre-shoot there were debates, anxious producers on both sides, egg-shell-walking meetings with Keith and private, one-on-ones to reassure the client. The shoot itself was punctuated by much throwing up of hands, expletives, late-night huddles in the freezing cold and a general radio-active buzz of imminent total meltdown. Just the way it’s meant to be. Because sometimes that is what it takes.

The best creative people I’ve known have never pretended to be anything other than what they are, and Keith, on that shoot, was a frenetic, messy genius. I was young and only understood later. He was completely honest. He was honest when he didn’t ‘get’ parts of the script, he was honest when he thought a client’s request was wrong; he was honest when he thought you were talking sh*t. I remember walking into the first cut approval and he warned me that he “didn’t like lazy creatives with no opinions ”. Luckily, I’ve never been short of those but the pressure was immense.

Keith stood by what he believed in creatively. He was always himself – unguarded and unsanitised, for anyone. I miss that. And we sure don’t see enough of that brand of balsy these days. Thank you, Keith, for your honesty, bravery and full-on commitment. RIP.”

Mike Schalit

“Keith’s unassuming humility, brutal honesty and disarming lack of subtlety, such an undervalued yet devastatingly pure and powerful weapon in today’s shallow world of false news and half-truths, will forever live on in my head and heart as a reminder to stay true.

Most pointedly and movingly, I managed to find an old email I’d sent to the maestro on behalf of Net#work, congratulating him on his Hall of Fame accolade. His humble reply made the hair stand up on the back of my neck when I re-read it today.

May it inspire you all.
Rest in Peace my friend.
I wish the family comfort and strength.

Mike & the Net#workers xx”

From: Keith Rose
Sent: Wednesday, 15 October 2014 6:20 PM
To: Mike Schalit
Subject: Re: Hall of Fame award

Jassis … What a mouthful.. Those words are better than any trophy… And penned by the wordsmith himself! No wonder you the man. Thankx so much for those beautiful words. I think I’ll cut them out and frame them and keep them forever! Keith

Sent from my iPhone

On 15 Oct 2014, at 12:08, Mike Schalit wrote:

Yo Keith

The master, ek se.
It’s about time the Loeries officially sanctioned your ownership of the Big Bird.
What an awesome tribute to your skill and vision to invent –  but even more significantly to your undying passion and humility to reinvent.

What a boykie.
And hey, you still give a damn.
You care. You push. You debate. You provoke. You laugh. You make mistakes.
But you don’t compromise.
So somehow you always end up pushing boundaries.
Even if you have to break a few budgets or hearts along the way.

 Heh, each time you rise to the occasion, never have so many wannabees and pretenders to the throne been more pissed off, more consistently, over so many decades. Only because they wished they’d done that. 

 You have inspired a generation and continue to inspire a whole new generation.
Something worth far more than any prize or one-off masterpiece.
A lifetime of doing what you love, compelling people to love what you do.

Big hugs, a small “lchaim” and a humungous “SALUT” 

Mike X & the Net#workers & the 140’ers

The Best of Keith Rose
(Video created to honour Keith when he was inducted into the Loeries Hall of Fame in 2014)

Anton Visser

“I had just joined Velocity as a new-ish director. It was a big deal for me because Velocity was, well, Velocity. And it was where Keith Rose worked. I came from agency side so obviously I knew about Keith, but in that way that you know about Lionel Messi, or Steven Spielberg. I’d probably been there for about three months and had only had one or two brief chats with the legend – it was down to me being nervous and, in retrospect, because Keith was actually more shy than people knew. It was a paradox about him that he could be larger than life but also quite introverted.

I was working late at the office on an edit. My editor had delivered a cut that wasn’t really popping yet, so I was trying to re-jig it. I thought I was alone, but then I heard someone quietly come into my space and it was Keith. He was also working late, as he often did. He asked me what I was doing, I told him, he watched the cut once, then mumbled a few tactful things to try and help me and left. I was a bit underwhelmed as I’d expected some kind of Yoda on the mountain top revelation.

Ten minutes later my phone rang with an unknown number. It was Keith, on the road home to Hout Bay. He started rattling off ideas so fast I had to write them down with a pen because I couldn’t type properly on my keyboard with one hand. He’d only seen the cut once but it was like he knew every shot, and he proceeded to rearrange the story in his mind, giving me a laundry list of good ideas that would prove to be essential to simplifying the story and making the ad come alive. “Move that close up of her earlier”, “Take out that big wide, you don’t need it.” I realised then how shy he could be, but also that he wasn’t just going to run roughshod over my edit the way another bigshot director might have done. Maybe he felt more comfortable doing it over the phone and not in person, but that was the day my relationship with Keith changed.

From then on I went to him regularly to get advice on things I was working with and to get the inevitable gold nuggets of filmmaking wisdom that he would casually throw out. And then he also started asking me my opinion, and that made me feel like a million bucks. Keith pushed us all – even the thought of him makes me want to push myself harder now. I spent nine years at Velocity becoming a better director in the brilliant light that he cast. I can’t think of anyone else who’s had the impact on our industry that he did. He was a by-word for excellence, scale and dreaming big. He was kind, generous, volatile, passionate, smart, outrageous and eternally young at heart. I often think back to that phone call and to what a true genius he was, and how he made time after a long day to delve into somebody else’s creative quandary. Thank you Keith, for your spirit and for all your help, and for showing so many of us the way. You were that Yoda on the mountaintop and there’ll never be anyone like you again.”

Alex Goldberg

“I’d like to tell you a story about Keith Rose.

For those who didn’t know him, Keith was a Director at Velocity. Not just any Director, he was The Director. A man who created some of South Africa’s most iconic ads. Allan Gray’s “Beautiful” being one of them.

One year they traded their epic Loeries parties for more intimate dinners with agencies. I was at FoxP2 at the time when we went to a little dim sum bar on Long Street. I sat next to Keith and we spoke an endless amount of shit on a variety of topics, obviously covering our best and worst ads. I complimented him on all his work, and he just said: “I just like to make stuff”.

I was about to pitch him this ‘great’ proactive idea (because it’s Keith Rose and why the hell not?) when I decided to ask him for a piece of advice instead.

He said, “Get to work and start your FU Fund.”
“An FU Fund?” I asked.
To which he replied “Your Fuck You Fund.”

“Put a little away every month and prepare. At some point in your life, someone is going to demand you do something that you don’t want to do. Something that goes against your vision, or just pisses you off. At that point, you can say “Fuck You” knowing you have something to fall back on.” 

That was Keith. A man with vision, purpose, and the ability to say “Fuck You” when it meant compromising on the work that made him a true legend of the game.

RIP Keith.” 

Allan Gray ‘Beautiful’ directed by Keith Rose

Steph van Niekerk

“Getting the call that Keith Rose liked your script and would come in for a treatment, is one of the highlights of any creative’s career. The first time it happened, I was really nervous to sit across the table from the legend himself. I shook his hand with sweaty palms. We went through his treatment and were looking at some references when the debate started about how raunchy we could go with said family fried-chicken brand. At one point in the argument, he called me a prude. And I called him an effing pervert. I was shocked. The words just slipped out of my mouth. Did I really call Keith Rose that? Turned out that slip was the start of a friendship based on mutual respect and endless teasing. Keith liked to be challenged. He made me feel heard and valued, even when I was a junior. But he also wasn’t scared of telling me when my ideas were kak. He made me a better writer. Even if it meant rewriting the freaking VO forty freaking times. I think that is the thing about Keith, he made everyone he worked with better.

It breaks my heart that in the end, no one could make things better for him. I count myself as blessed and honoured to be among those whose lives have been touched by the Keith Rose Magic.”

Paige Nick and Karin Barry

“He was no ordinary man.
He devoured life. Swallowing large chunks of it whole, refusing to chew.
No ordinary man.
He lived enough life for ten people.
Fame stuck to him like glue.
Part myth, part legend, part of us all…”

Keith Rose, you made Karin Barry McCormack and I rewrite that copy for that Allan Gray James Dean Legend ad maybe 20 times. We would have rewritten it 900 times if we’d known how relevant it would be now.

You made us all better at what we do. RIP you legend.
You were no ordinary man for sure. It doesn’t seem real or fair.

Love Paige and Karin

Allan Gray ‘Legend’ directed by Keith Rose

Mariana O’Kelly

“My dearest Keith

I could never call you dear to your face, as you probably would have laughed at me, thinking I was trying to manipulate you into shooting that shot you never liked.
But you have always been dear to me, even during the times you called me girly, or worse, Marianne and not Mariana.
But I never corrected you, as it was insignificant info in the light of the bigger picture we were busy creating, together.
When we got to work with you, it was serious and the expectations were high. Our nerves were usually shot, because you didn’t come cheap.
Good things never do.
But you set the bar so high, we had to stand on our tippy toe to reach where you were at.
On my first shoot ever with you, I fought with you over a guy wearing make up. You told me it was just to accentuate his features and that one would never see it through the lens. I asked to see through the lens and your face said it all. I was soooo scared of you. But I always knew that behind the bad remarks and putting the agency far away in the VT tent, there was a genius, wanting to create, without barriers and budgets and creative wannabee interference. I learned to respect that and I eventually learned to just let you do your thing. Those were the best films. The ones you did without our interference.
This girly will miss you dearest Keith. I will miss your negative remarks, your nervous laughter when an edit was finally approved, I will miss your passion, your love for story telling, story crafting. I will miss your oddness, your amazingness.
Nobody will ever be able to replace you. You have been unique in your character, vision, your approach, your fearless attitude, your standard.
Farewell my dearest Keith.
Respect. Always.
Marianne (Mariana)”

Esther Campbell‎

“I met Keith In 1980 and we went on to do many commercials together. He was an assistant cameraman at the time. He was naughty, cheeky, and so, so wonderful to have on set. He always made us laugh and brought a light quirkiness to the set. He had a huge presence and energy. Once he set this focus points, he always went on the frame up shots…He would quietly call me over to view his shot. It was usually beautiful. He had an amazing “eye”… even then. After the shoot, we would sit and chat and often went back to my flat in Yeoville or to Rocky street and Rumours…. We never tired of talking about all aspects of filmmaking.
He was fiercely ambitious and always openly stated that he was going to be a director/cameraman. Somehow we all knew he would achieve that goal. I went on to produce with Giaco and Keith joined Feldman Cornell. I remember burning with resentment that they signed him. He was arguably our fiercest rival….and together with David Feldman they started making award-winning (and beautiful) spots. So although we usually quoted against each other, Keith never made it personal and there was mutual respect. When Giaco and I relocated to Cape Town in 2003, Keith and Barry opened up their company to embrace us for a year. That takes a special kind of person. And special he certainly was. After Giaco passed away I was proud that Keith gave the tribute speech at the Loeries. During that very difficult time he called a lot and communicated with me on such a profound level. I was mired in grief and he provided some balm for my soul. I remain profoundly grateful for that. To say I admired him, does not cover the feelings I felt towards him. Yes, he was an incredible talent, and he achieved success at the highest level, but add to that a humble, self-effacing man with a huge heart. I have yet to meet someone who does not like Keith…. he had very few enemies …. and that is a huge achievement in our business.
Some believe there are three kinds of death…the third one is when people stop using your name. I believe Keith will be remembered and spoken about for a very long time.
Keith, say hi to Giaco up there and may you two continue to shoot the light.”

Stephen Gordon

“I have so many stories about Keith. We were inseparable for many there are so many, but one stands out now. When he was in Toronto working on an edit for a job he had done. We were walking on queen street ( a cool shopping street in Toronto) and we came a shop with a big Spiderman outside the store, one that you blow up, like a balloon. Keith said he wanted that Spiderman for Sean, Sean loved Spiderman. So Keith goes into the store and asks for the Spiderman. The guy in the store, says no ways can he have it, it’s not for sale. Then Keith asks if the ship stuff to South Africa? The guy says no, but he can give Keith the name of places that will. Keith, in Keith’s way says nothing, gives him that Keith stare and proceeds to walk around the store buying all sorts of goodies for the kids. Brings it to the counter and lays it all on the counter. The guy says cash or credit card, so he enters all the goodies and it comes to $3600CAD. Keith says and how much is the shipping and the Spiderman? The guy looks at Keith, like he is mad, and says that they can organize shipping at a price and will give him the Spiderman for $1200CAD. Keith buys it all and leaves, the store, the guy is dumbfounded.

Only Keith could have got away with that, He was so determined and would never give up, that was the Kefee. Nothing would ever stop him and he would never take no as an answer. Geez, I cannot believe he is no longer with us. But I was so lucky and fortunate to have him as a friend, we spent a lot of time together and he taught me so much.”

Pepe Marais

“I remember back in the day when I was a young Art Director at Network BBDO and every profound piece of work from our industry had Keith Rose written all over it. I dreamed of working with Keith then. I dreamed of working with him for many years after founding Joe Public. Sadly, for some reason, this will be one of my dreams that was never meant to come true. Having not known Keith and not worked with him personally, I can only speak to his work. From BMW,s Mouse for Hunts, to Investec’s Rice Fields for Network, to Alan Gray’s Beautiful and everything beautiful in between. Each frame spectacular. Just like the Rose of Soweto was and will forever be the super middleweight champion of the boxing fraternity, Keith was and will forever be the super heavyweight Rose of our advertising industry.

His work punched.
Rest In Peace, Keith.”

BMW ‘Mouse’ directed by Keith Rose

Neil Meyer

“As a youth I distinctly remember; being absolutely terrified every time I watched that Mercedes-Benz hurtle off Chapman’s Peak, crying every time I watched a little elephant wander around the desert, laughing every time I watched David Kramer saying veldskoen, cheering every time I watched a bunch of dogs racing along an obstacle course in slow motion, and being in awe every time I watched that Golf GTI fly through the air. Unknown to me at the time, Keith Rose put me through all these emotions.

Many years later I had the privilege of working for the Keith, and he made me feel those emotions all over again. Only this time the circumstances were very different. Assisting him in creating and crafting the masterpieces that only he is capable of, he had me; terrified when he sauntered into a review, crying every time he trashed my ideas, laughing every time he explained something in that high-pitched Vaalie accent, cheering (internally) every time an idea I put forward saw the light of day. And, most of all, he had me in awe every time I saw the genius of his brain come to life in the final product.

The Rosemeister was one tough ball-bag and we will all miss seeing more of his work.”

Mercedes-Benz ‘Chapman´s Peak’ directed by Keith Rose

Don Bryan

“I write this tribute, through tears, for a man that I, like so many, believe was truly exceptional. Keith occupies the same space in my mind as Dan Wieden and David Droga. I suppose when I really think about working with him it leaves me on the floor at just how much he taught me. He was, and is, one of my true heroes.

Keith had this amazing ability of taking an idea, that you believed was pretty great and making it dramatically better. While the rest of us measure our contribution in inches, you can measure Keith’s in miles. He had an incredibly clear vision of how a story needed to be told and kept everyone on a project true to that vision. He never got distracted by all the strong opinions, the noise of clients and creatives, unless they were making the work better. This should be the number one character trait in all creatives but I have never met one that had Keith’s vision or ability to hold a whole team to that vision.

While most of us run away from complicated problems on a brief, Keith ran towards them and seemed to, almost effortlessly, solve them in an interesting and unexpected way. He created a culture around him where people were challenged and engaged. And made everyone perform at a level they didn’t realize was possible.

But I guess the two qualities I valued most in him were firstly his loose grip on reality. He was never distracted by petty things like, “can we actually do this” or “is that even possible”. He knew he operated in a world where magic is possible and so he did the things some of us can’t even dream of. Secondly his inability to compromise. How many of us sat on a set with him, half a day past what we had a budget for, while he removed a tree that was killing his shot? Or rebuilt a studio so that the light could be in just that spot? I will miss his dedication to excellence more than I can express in words.

In spite of not being very tall, he carried so many of us on his shoulders and lifted us to a height most of us couldn’t even imagine before working with him. I am so sad he is no longer with us and I am broken at the tragic way he was taken from us before he needed to be. I am also reminded that as I mourn his passing there are many that were so much closer to him and my love goes out to all of you for your loss.”

Linda Bogle

(Picture: Keith Rose on set – Investec ‘Racing’)

“I worked for Keith Rose exactly 20 years ago (1998) as his Production Manager.
The team at that time comprised of Keith, Colin Howard (Producer), Greg Gray (AD) and Mike Hoyte (Scout and Keith’s Guy). Corvette (that was Keith’s nickname for Jordan Knight) joined us on some of the projects.

The two standout jobs for me that we did during this time were Mercedes SLK “Mannekin Pis” and Investec “Racing”. And the memories come flooding back.

We travelled to Rome to shoot ‘Mannekin Pis’ – I couldn’t believe my luck as I was included (and it was my first time in Rome). Kerry Rose joined us, thank goodness for another girl around The Boys.

Keith was the most generous person to be around – he took us out for dinners, we went to Cinecitta studio’s (and I learnt some history on Fellini), we walked through the Rome streets at night, laughing.. We shot for about 4 hours one morning – I remember going off to find coffee for the SA crew and agency and when I returned, the set had wrapped before breakfast.

Investec Racing was a job that nearly made me leave the film industry. It grew by the hour – pushed forward by Keith. It was a monster that became a very beautiful piece of work. It taught me how much stress I can take, how to become more efficient and a better manager.

Keith had a very naughty sense of humour, he loved to tease and of course, I was perfect bait. He made us laugh (mostly at ourselves). He pushed us all, all the time. He was the King of commercial directors and you did whatever it took to make it work, hell you were in The Rose Team. He exhausted us, drove us to the edge but always the result was worth it. He always delivered the most beautiful work.

RIP Keith although I doubt that will be the case.
You will be teasing, laughing, pushing the bar and making beautiful pictures wherever you are.

(Picture: Shooting in Rome – Mercedes SLK “Mannekin Pis” Greg directing Italian cast who could not understand English while Keith watches on)

Oh and then the Loerie’s in Sun City that year…”

Investec “Racing” directed by Keith Rose

Tim Beckerling

“I remember the first time I worked with Keith Rose. It was the biggest job of my career thus far and I was nervous and a little star-struck by the legendary man. He was unsure of me the whole way through the production process, friendly, but with his trademark inability to hide how he really felt, as if to say, “Who the fuck is this guy”? He would review and double check every decision that we made down to the most granular detail, like he was the Creative Director, Client and Director all at once. Watching him work was like watching a Netflix series that grips you and just won’t let go. Exciting, unpredictable and fascinating. A man truly at the top of his game, that you couldn’t help learning valuable lessons from with each passing second. We reached post-production on the job and he sent me off to do the Audio Design on our spot after a full 24hr overnight Grading Session, a process that if you ever went through with Keith, you’ll know a level of obsession with detail few others ever will. Inspired by him, the Engineer and I put our hearts and souls into that Soundtrack and many, many hours later we nervously offered up what we had done. He called me back almost immediately, and for the first time during the whole production he used my name out loud. “Tim, it’s fucking awesome!”, he said. To this day, when I attack that specific part of my job, I try to achieve the same level of craft and attention to detail that Keith inspired in me during that process. To always up my game and really give a shit about what I am doing. And when I first present something to a room full of people, I try to make sure that if he were there, he’d approve.

RIP Keith Rose”

Annelize Frost

“Keith worked hard.

When Keith developed a script into a commercial, Keith breathed that script. That story. He would always be thinking of the best possible story with endless possibilities to execute. While he was driving fast, while he was sleeping and sometimes not sleeping and then the next morning after a late night at the office, he would announce that the story idea changed. Again.

He was the force.
He was the firecracker behind you with a long or a short fuse. Work days with Keith would start before sunrise and not really end. While prepping a job, you would go home only to sleep and then straight back to the office. And when arriving at the office in the early mornings, Keith would already be there. In the boardroom. Looking at his pictures. Hundreds of pictures fastidiously laid out in an order that only a few of us learned to understand. His thinking. The pictures were postcard sized and covered the 7meter boardroom table, the boardroom glass walls and sometimes we brought in more tables to accommodate the thinking.

“A Picture describes so much detail…gets everyone on the same page” Keith would explain. “Look, look at the light in this one… Look at the way he is dressed or her expression, pointing at another picture, now when you show someone this picture…they will understand what you would like to achieve in a shot…or maybe they will not.”

I once asked Keith if he would ever make a feature film and he answered: “There isn’t a room big enough, maybe a warehouse…” pointing at the pictures.

For Client and agency presentations the selected pictures were stuck down on 1meter by 1meter cardboards. “Keith’s boards” the team called them. The weight of the presentation bag would cut into my shoulder. You never dared to stick a picture skew or cut a border frame too thin around a picture on one of those boards. When you disappointed Keith, you were the one that felt it. Keith’s eye to perfection and straight lines were uncanny and he could guess the length of a room by a thumb suck. He sized and measured everything up. He never used the gifted laser measurer. Just pointed with it.

When in an agency or client presentation, I would be amazed and teary-eyed proud, because even though I would have been part of the production from the beginning, I would hear Keith’s version of the commercial’s storyline. He was incredible to watch and listen too while describing every detail and character with so much enthusiasm he would go red in the face.

In another time Keith would have been the storyteller by the fire, the circus ringmaster. A Showman or gatherer of weird and never been seen before creatures. He would have been a time traveller or magician. A King.

Keith never stopped planning or thinking about the job and what had to be done. Days leading up to a shoot, we had meetings. Briefings. Rehearsals. Fittings. Changes. More changes. Every detail was scrutinized. Questioned. Another crane was ordered. Lists were made. Keith checked that everybody checked on each other. Nothing was left to chance.

When the shoot day came, Keith would arrive. He would walk onto set. He would walk around on his own. Sizing up the location. Quietly look at the set. He would blow his nose and clean his glasses and then without looking at a camera, announce that the whole unit had to move to the opposite side. It was all in his shot. You could never be completely prepared or sure with Keith.

I am incredibly aware of the massive fortune I received to have been mentored by Keith. He taught me how to look at things in a different way, through the lens of a camera and at life. He taught me how to size things up. Mostly people, but also what was important to me. He was generous. He was sensitive. He had an incredible sense of humor. He taught me how to be fierce and to stand my ground. He believed in me. He taught me that ordinary would just never do and to always take a ladder on a location scout, to see beyond the wall. The perfect location or camera position was always on the other side.

I am forever thankful, Keith. For your time you gave me. I will always look beyond the ordinary because of you.

Annelize Frost
Assistant Director / Rose Team
2007 – 2014”

Daniel Kaplan

“I first met Keith Rose over 20 years ago as a young clueless runner at Velocity. He arrived in a loud & large American car. I would later be ordered nonchalantly to move this giant piece of art around the parking lot (with my 8 months of driving experience). Never again did I fear my mothers station wagon. It was one of many times my inexperience would be challenged by Keith. A man so foreign to my upbringing that I constantly had to reinterpret & recompute my position and understanding.

“It’s shit” was his response to my finest day of location scouting & photography. My interest in photography became a love of framing, squatting, climbing trees, tiptoeing and leaning over to find the “other way” to do it. I became one of the smallest cogs in some of those iconic ad’s – something I’m still proud of to this day.
We would stumble upon each other many times in the forthcoming years but I was always greeted with that welcoming & knowing sparkle in the eye.
Thank you for pushing and prodding me to be better. You were a tour de force and will be sadly missed. RIP Keith”

Ronwin Barnes

“A true Legend.

I’m truly honoured to have had the privilege of working with you and being a part of your team. You always pushed us to do our very best. What an inspiration and mentor to me and so many of us.

RIP Keith Rose “

Jordan Knight

“I was lucky enough to start on Keith’s team in 1997 as his Production Coordinator when Michael Hoyte had decided he would rather focus on location scouting.  Linda Eedes Bogle was his P.M and Colin Howard was his Producer.  When I first started on his team I was a bit naive and had no idea who he was. Needless to say, I had my wake up call after working on my first production with him.  I was fascinated with his research and his mind and it made me feel alive and want to achieve more than expected on his productions.   I still revere his work and consider all the productions I worked on with him as trophies in my career.  

Some of the work I got to work on were Japan Tobacco, Investec “Racing” & “Grain of Rice Campaigns”.   The Investec Racing Campaign was the first time a Client had invested such a large budget in a TV Campaign. Chris Bass who was his Art Director at the time was inducted into the U.K Art Guild after the “Grain of Rice Campaign”.    Dentsu, the Japan Tobacco Client came back to shoot with Keith repeatedly and Keith’s big heart, he generously opened his home and would entertain in the kitchen tantalising our taste buds with his culinary heart. 

I went away to U.K for 2 years and when I returned, I was lucky enough to walk straight back onto the team as one of his P.M’s and got to work on the Molson Beer Campaign whereby he ‘re-created the first moon landing’ and did a spoof of a hockey game between America and Canada.  

Keith did nothing small.  He was always humble and I remember he did not enjoy being ‘in front of the camera and being interviewed.  The Oppenheimers came to film with him twice.
He always stood in his vision and he knew what he wanted and he was admired and respected for that. I have so many memories of moments on his shoots that I will always hold close to my heart. 

I am sorry that your demons got the better of you.  You are sorely missed.  I am truly grateful I got to experience your creative genius and have a small part in helping create your art.
R.I.P. Keith.  Condolences, to Kerry, Marie Louise, Sean, Luke and Roland through this time.”

Cathy Steed

“One of the biggest men I’ve ever met. A giant with a huge generous heart and a laugh that was instantly contagious. Your spirit is far too big to be contained in such a small space. Fly free Skeef. You are so much a part of those you inspired and you live inside all of us who were lucky to know and love you. You are loved and with us always. Thank you for your love. Legend xxxx”

Paul Warner

“To have been in the presence of Keith Rose, was to have been in the presence of creative greatness. My career was inspired and indeed created by Keith – I was so fortunate to have enjoyed a very special relationship with this man. He pushed me hard, had no time for compromise nor mediocrity – instead his work filled your head, the screen, your heart.

Keith was one of the founders of the South African film and advertising industry that put this country onto the world stage. His vision, his artistry and the scale at which he operated, was unsurpassed. Not only did he give birth to many of the past and current filmmakers, but all that passed through his door, schooled by him, were indelibly shaped by his vision. The teams he built around a project, from location managers to art departments, lighting teams, editors, animators, were exceptional. When he worked he weighed in on everything, pushing the creative industry – and ultimately the marketing industry to achieve more.

He pushed the boundaries – beyond the boundaries – always, never afraid of a helicopter or four…

Keith – thank you for being you – a one of a kind, delightful and determined human being.”

Tristyn Desmarais von Berg

“Keep the sentence’s short. Make sure that each sentence communicates an idea. No fluff!

Straight out of film school, calling myself a director he laughed and pointed to where the kitchen was and how he liked his tea. Between 2005 and 2012 I worked as Keith’s creative assistant. He was my mentor, and I was his apprentice. I owe much of who I am today to working and learning from not only him but the world he forged around him.

I wish to pay tribute to this man – a force of nature.

When you worked at Velocity Films you realised you were working in a world-class office. You appreciated the standard of excellence by the people around you. You fed off their passion and brilliance. It felt like every day you were meeting with the most incredible talents in the world. Into his office, his personal glass-walled fiefdom, came the grips assistants’ and global agency chairmen. Each came with the expectation to be inspired, challenged, invigorated.

Scripts came in from all over the world. They came for a piece of Keith, and they got so much more than they ever expected. He began with the script, and layer by layer, photo by photo, wardrobe by wardrobe he collaborated pushed and pulled those around him to dream bigger.

Fuck, was he a craftsman! Obsessive, compulsive, practical, visceral. He was the son of a miner, he was a grip, a gaffer, a dop, a director haha a wannabe fashionista! Man those haircuts!

I can’t begin to describe the character the generosity the passion that Keith gave to the world. I can’t give anecdotes without writing a biopic which even then you wouldn’t believe…

When a brilliance is so pronounced it creates its own gravity. You orbit around it. Keith was Velocity Films and so much of South Africa’s greatest advertising in the last 30 years was produced by the people who lived, learned and worked with Keith.

I am one but one of them.

My thoughts extend to all those whose lives he touched, to my old Velocity Family, who I miss very much. My heart opens and pours all its love for Marie Louise, Roland, Luke, Sean and Kerry’s family.”

​​​​​​ John Hunt

“Keith Rose was the Golden Director during, what many believe, was the golden age of television commercials. Both locally and globally, he was the go-to guy when you had something special. Almost single-handedly, he dragged South African TV production to a level where it was benchmarked against the best in the world.

He was less of a talker and more of a doer. While excited Creatives babbled on about their brilliant storyboards, Keith barely said a word. An arched eyebrow or a nod of the head was about the most you could expect. His genius was that he could articulate a complicated idea into a single memorable visual. He spoke in pictures that seamlessly joined together to tell an idea in breathtaking simplicity and beauty.

He was a mentor to hundreds of people in the industry. Sometimes, without him even knowing it. He was impossible to copy but was always held up as the ultimate point of reference.

Keith never over-intellectualised or lost himself in the latest buzzwords. His work did the talking. And if you wanted to fiddle with his edit, you better have had a damn good reason.

Wherever Mr Rose is now, I guarantee he’s perfectly framed. And the lighting? Well, obviously, it’s perfect.”

Andrew Chandler

“Keith Rose had the most unbelievably mercurial visual intuition that I think I’ve ever encountered in a director – for many reasons – the chief one being that I could never fathom where it came from in such a seemingly unlikely person. His grasp of visual abstractions was truly astonishing – and lightning-like. He was impossible to work with and reduced me to tears many times. But he had an absolutely perverse way of making me collapse with laughter at the most utterly inappropriate things – on reccies or after hours – in a mischievous schoolboy way. I can honestly say that watching his ability to be in control of literally dozens of aspects of a huge production simultaneously – was perhaps the most educational exposure to the entire process of filmmaking I ever had – if not one of the most frustrating.”

Khandiz Joni

“I mean I don’t even know where to begin, I have many fond memories… this may be a bit of a ramble. 

Ahhh, Keith.
I am at a loss for words, even as I write this. Your bark was bigger than your bite… and your cheeky smile won us all over.
Thank you for taking a risk on me all those years ago and giving me (many opportunities) to work with one of the greats. A visionary that I still hold talent up against. You were one of the few people who got away with calling me Khand. But it made me happy that you did.
Some of the best work I ever did was under your direction, and you made me better.

Thank you Keith. Heartfelt condenses to your entire family. You will be missed”

“These are the words that have made the most sense to me over years.
I’m old. What that means is that I’ve survived (so far) and a lot of people I’ve known and loved did not.
I’ve lost friends, best friends, acquaintances, co-workers, grandparents, mom, relatives, teachers, mentors, students, neighbours, and a host of other folks. I have no children, and I can’t imagine the pain it must be to lose a child. But here’s my two cents…
I wish I could say you get used to people dying. But I never did. I don’t want to. It tears a hole through me whenever somebody I love dies, no matter the circumstances. But I don’t want it to “not matter”. I don’t want it to be something that just passes. My scars are a testament to the love and the relationship that I had for and with that person. And if the scar is deep, so was the love. So be it.
Scars are a testament to life. Scars are a testament that I can love deeply and live deeply and be cut, or even gouged, and that I can heal and continue to live and continue to love. And the scar tissue is stronger than the original flesh ever was. Scars are a testament to life. Scars are only ugly to people who can’t see.
As for grief, you’ll find it comes in waves. When the ship is first wrecked, you’re drowning, with wreckage all around you. Everything floating around you reminds you of the beauty and the magnificence of the ship that was, and is no more. And all you can do is float. You find some piece of the wreckage and you hang on for a while. Maybe it’s some physical thing. Maybe it’s a happy memory or a photograph. Maybe it’s a person who is also floating. For a while, all you can do is float. Stay alive.
In the beginning, the waves are 100 feet tall and crash over you without mercy. They come 10 seconds apart and don’t even give you time to catch your breath. All you can do is hang on and float. After a while, maybe weeks, maybe months, you’ll find the waves are still 100 feet tall, but they come further apart. When they come, they still crash all over you and wipe you out. But in between, you can breathe, you can function. You never know what’s going to trigger the grief. It might be a song, a picture, a street intersection, the smell of a cup of coffee. It can be just about anything…and the wave comes crashing. But in between waves, there is life.
Somewhere down the line, and it’s different for everybody, you find that the waves are only 80 feet tall. Or 50 feet tall. And while they still come, they come further apart. You can see them coming. An anniversary, a birthday, or Christmas, or landing at O’Hare. You can see it coming, for the most part, and prepare yourself. And when it washes over you, you know that somehow you will, again, come out the other side. Soaking wet, sputtering, still hanging on to some tiny piece of the wreckage, but you’ll come out.
Take it from an old guy. The waves never stop coming, and somehow you don’t really want them to. But you learn that you’ll survive them. And other waves will come. And you’ll survive them too.
If you’re lucky, you’ll have lots of scars from lots of loves. And lots of shipwrecks.”

Gerry Human

“I’m so sad to hear we have lost such a great hero of filmmaking and creativity. My heart goes out to Keith’s family and the many, many people who loved him so much.

I first met Keith at a party in Yeoville, back when production co’s had parties in Yeoville.

Depeche Mode or something was thumping out and the air was thick with smoke — ’80s hotbox stuff. I was absolutely in awe of his work with Brian Searle-Tripp, Willie Sonnenberg and John Hunt et al. Suddenly, there he was, the great Keith Rose, just standing there doing what he did best — watching, scrutinising, contemplating.

Imagine his annoyance when his broody gaze was broken by this half-ass junior art director, who strode over and said, “Are you actually Keith Rose?”
He said, “Ja.”
So I said, “I love you, man.”
Well, that didn’t make us instant BBFs but at least he didn’t punch me.

Working with Keith was always a proper education. Like commercials bootcamp.

For a guy who had every reason to behave like a big deal, Keith was an incredibly humble, generous and kind human. Of course, he was incredibly tough, too, but all for the right reasons – he only ever cared about the end result. Everything else was a side show.

Keith’s colossal talent helped build businesses, careers, reputations and, not least, a positive, creative image of South Africa in the eyes of the world.

Keith’s death is like a punch to the heart, but it’s what he left behind that will live on forever.”

Saki Bergh

“When we had started Left in 2006, Keith Rose was already Keith Rose.

As Left grew I wanted to work with the best, and for me, he was the best. The first time I met him was very brief. I was in a grade with Adrian and Keith popped in and the main thing I remember was him telling Adrian, watch out for those reds, they bleed like hell on tv

I was even more intrigued by him after that and became more determined to work with him. I put it out there into the universe and so with the help of that and, specifically Leigh Ogilvie, telling him good things about me, I finally got to work with him

So, I don’t know if he had changed by the time I started working with him, but none of what I had heard was true. It did always feel though, like he already knew the answer to his questions. What I found though was that he was a collaborator. He would listen to me, or more, was really interested in what I thought or had to offer. If you feel valued as an editor, or any creative, it empowers you to do even better and you are up for any challenge, and he did challenge me.

He is probably the cleverest, most knowledgeable filmmaker/storyteller and I’ve had the privilege to work with. I’m incredibly annoyed that all that knowledge he had is now lost because so many people still could have learned from him. All he wanted to do was make the best ad possible by any means. He kept challenging himself. That’s why no one Keith Rose ad looks the same. When fearless like that and taking chances, he was gonna fail at times, but most of the time he succeeded because of the honesty of his intentions.

I feel immensely grateful that I had been given the opportunity to have worked with him. I learned a lot from him, obviously, but he helped me more in remembering why I was drawn to making films, editing and telling stories.

I have already missed not being able to work with him, which for me was more than just work, and now I’m stupidly sad that I would never again get that opportunity.

All the very best Keith Rose”

Teresa Leslie-Munchick

“I, like the whole advertising industry, was reeling yesterday in shock at the tragic news of Keith’s death.
He indeed is iconic and a legend and his contribution to the industry both through the standard of his work and his mentoring of directors, producers and crew. Working at Velocity and particularly in Keith’s team is a right of passage and a badge of honor.

My relationship with Keith is for the most part personal, although Heather and I (heatcasting) did some casting for him.

I knew Keith in his David Feldman days and in fact, it was through him I was introduced to David. David and I went on to have a relationship for 2 years.

Barry moved here when he and Keith started Velocity Films. Barry and I met and when we got married Keith was Barry’s Best Man. We had Caitlin and Lerat came into our lives and we were blessed to have a second daughter.
So basically it was because of Keith that I now have my beautiful daughters (and of course had a very long marriage)

Marie-Louise was a good friend of mine and I was instrumental in them getting together. They went on to have Sean and Luke and Roland Marie-Louise’s son gained a father.

Although we had not seen each other for years our lives and history were so intertwined.
Keith and I were buddies, I had almost a brotherly relationship with him at one time. We partied hard both privately and at The Loeries and had some heady days in Cannes. I was fortunate enough to be there when he won his first Gold Lion. (And I believe South Africa’s 1st though I stand to be corrected) (The days before Barry red-carded me from Cannes due to my sterling performances and my awards for being the last man standing at the Gutter

He used to call me Squeeza which somehow morphed into Squeezeme,
which he would bellow (as much as Keith bellowed) when he would see me unexpectedly.

I am eternally grateful having had Keith in my life. Who knows what my life would have looked like had I not met Barry.

I mourn for Marie-Louise, Roland, Sean, Luke and Kerry and family.
My heart goes out to his family and friends. I know some of the ex Velocity staff are bereft. My friend Nicola who was integral to Velocity and played a big role in its success over a span of over 20 years, but knew Keith for years before that. Yoli v d Merwe and Karen B who I spoke to yesterday and are in shock. Barry who is sad, it was like a marriage,
although you get divorced subsequently doesn’t erase your history or the good and successful times you’ve had. The list of people who worked with him at Velocity is too long to mention. My love goes out to all of you.

Thank you Keith, hope you have found peace and hope you have an aerial view of the industry mourning.”

Pete Khoury on behalf of the Creative Circle

Creative Circle Mourns Passing Of Industry Legend Keith Rose

“Keith was a giant of our industry.

He pushed all of us, his team, the agency and the clients towards greatness. He did whatever it took to create spectacular work – not to just get the job done. It is something that I always admired about him. Especially in this day and age where what we do has become so commoditised. In my opinion, Keith was not just an amazing director, he was an amazing DOP, producer, art director, gaffer and even an engineer at times, if the job required it.

He once needed to put a crane on a heritage site to get the shot. And that was the shot he wanted, nothing else. The city refused permission, but this didn’t stop Keith. He got a bigger crane, the biggest crane I have ever seen and placed it on the other side of the building, off the heritage site, just to get the shot.

Keith always reached for the iconic.

He was always trying to do something no-one had done before or looked at in a certain way before. His crafting was amazing to watch and he pushed us all to get there. And sometimes when you push things the way Keith did, you fail. On certain jobs, in his efforts to reach the unprecedented, he failed spectacularly. But his epic achievements far outweigh his failures. He would rather fail in this way than do something ordinary. And that’s what I loved about him.

Keith also helped build our industry into what is today; not just the film industry, but the advertising industry at large. Personally, he opened my eyes to the way things should be done when I was just a junior in this industry and it forever changed the way I did things.

Maybe it’s a bit unfair that because of him I expect more out of everyone else that I work with; because I have seen the best in action. And I am very grateful for this.

Thank you Keith for your role in who I am today. I am sure there are many people out there that would say the same. You challenged us. You supported us. Everything about you was epic. We are all poorer without you. I hope that in the years that come we can all hold the bar up to your standards in the work that we create.

Your legacy lives on, in all that knew you.”

X Rebirth Craft Space Fly Egg Collection is a full service General Contracting and Construction Management firm providing services throughout North Carolina.

How Spacecraft Fly

Graham Swinerd

How Spacecraft Fly Spaceflight Without Formulae

CoperniCus Books An Imprint of Springer Science+Business Media In Association with praxis puBlishing ltd

Graham Swinerd University of Southampton Hampshire, UK

ISBN: 978-0-387-76571-6 e-ISBN: 978-0-387-76572-3 DOI: 10.1007/978-0-387-76572-3 Library of Congress Control Number: 2008931301 © 2008 Praxis Publishing, Ltd. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Published in the United States by Copernicus Books, an imprint of Springer Science+Business Media. Copernicus Books Springer Science+Business Media 233 spring street New York, NY 10013

Printed on acid-free paper 9 8 7 6 5 4 3 2 1

This book is dedicated to the memory of John Robert Preston (1952±2007)


The late science fiction author Sir Arthur C. Clarke, in an article published in 1945 in Wireless World, suggested that it would be possible to build a global communications system by placing artificial satellites in a strategically located orbitÐthe so-called geostationary Earth orbit. From their vantage point high above the Earth, the satellites would be able to relay information from any place to any other place around the world. Just twenty years later, Clarke's tentative proposal became a reality with the launch of the world's first commercial communications satelliteÐIntelsat 1. Now, a further four decades on from Intelsat 1, many of us would find it difficult to adjust to a world without satellites. Our cars and mobile phones routinely come equipped with satnav, the weather forecasts that we watch on our satellite TVs display images taken from space, Earth observation satellites monitor the threat of global warming and science spacecraft, such as the Hubble Space Telescope, have transformed our view of the universe. There can be no doubt that communications satellites, and the plethora of other satellites in diverse orbits, have profoundly affected the way we live. But how are these satellitesÐthese marvels of technologyÐdesigned? In what orbits can they operate? Once they are in orbit, how can we control them? What hazards do they face? How do we get them into orbit in the first place? Moving beyond Earth orbiting satellites, how can we design and propel spacecraft to rendezvous with comets or land on other planets? And, perhaps most importantly of all, what is the future of manned space exploration? In this highly readable and entertaining book, Graham Swinerd shares with us his immense and personal experience of the first half-century of the Space Age, to answer these and many other questionsÐand all without recourse to mathematics! Stephen Webb Portsmouth, England April 2008


As I write this introduction, it just happens to be 50 years since the launch of the first spacecraft. This dawning of the Space Age occurred in October 1957, when the Soviet Union lofted a small satellite called Sputnik 1 into orbit. Since then, space activity has become an integral part of our culture, and from the perspective of the 21st century it is hard to appreciate what a major technical achievement and political coup Sputnik was. Although it did very little in orbit, other than to announce its presence through the transmission of a simple radio message, it nevertheless galvanized the other superpower, the United States, into a vigorous space program that ultimately led to men walking on the moon in 1969Ðjust 12 years later! When I was a boy, growing up in the early 1950s, my interest in space was sparked by an elementary school teacher, Mrs. Christian, and her inspirational gift of teaching science to her young class. When I look back over a long career in space, both in industry and academia, I have come to realize that this ball began to roll in that early classroom. I have a lot to thank that teacher for, who planted a lifelong interest and enthusiasm in me. At that time, the Space Age was yet to begin. Nothing was in orbit around EarthÐ apart from the moon, of courseÐand the exploration of the solar system was yet to begin. The only source of information about the planets had been gathered by astronomers through telescopes, and the only images of planetary landscapes were those produced by the space artist's brush. How different it is today. Since the heady days of Sputnik, all of the planets of the solar system have been visited by robotic interplanetary spacecraft, with the exception of far-distant Pluto. Even as I write, this omission is being rectified by the launch of the New Horizons spacecraft in January 2006, which is due to fly by Pluto and its companion moon Charon in 2015. Ironically, in August 2006, just a few months after the launch, a gathering of astronomers in Prague stripped Pluto of its status as a planet, although the scientific objectives of the mission will of course not be compromised by this intriguing decision. Longer-term studies of the planets have also been undertaken by sending spacecraft to orbit the planets Venus, Mars, Jupiter,



and Saturn. These missions have been extraordinary and surprising, having discovered a rich variety of features beyond our scientific expectations and imagination. Small bodies in the solar system, such as asteroids and comets, have also been the focus of recent space missions. One such example is a spacecraft called Rosetta, which was launched by the European Space Agency in March 2004 to rendezvous with, and orbit, a comet in 2014. As a consequence of all this activity, it is possible for the imagination and enthusiasm of today's schoolchildren to be stimulated by real photographic imagery from far-flung regions of the solar system. Another space enterprise that has revolutionized our understanding of the universe is the launch of large space observatories into Earth orbit, where a clearer view of the cosmos is possible above the obscuring window of Earth's atmosphere. The most well known example of such a spacecraft is the Hubble Space Telescope (HST), which has revolutionized observational cosmology, to say nothing of the aesthetic quality of many of the images returned by the spacecraft. At the time of this writing, the lifetime of the HST is almost up, and the development of a second generation of large space telescope is currently underway. The new observatory, named the James Webb Space Telescope, will be launched around 2013 and have optics nearly three times larger than Hubble. It is hoped that the new telescope will be able to see the first stars and galaxies that formed after the Big Bang! As well as all these scientific projects going on, there are a multitude of satellites in Earth orbit providing services to underpin the technological society we have here on the ground. These application satellites have become fully integrated into our lives, but without us really noticing that they are there. Perhaps the best example of this is global communications. If you talk with someone on another continent, your voice is most likely carried by a spacecraft in high orbit. Another example is satellite navigation (``satnav''), the use of which is rapidly spreading into business and leisure activities. At least in this case, we know that satnav has something to do with satellites. The other major application is Earth observation; there is an armada of spacecraft in low Earth orbit with imaging cameras, and other instruments, directed down to Earth's surface. Data from such spacecraft are used for everything from town planning to agriculture, and it is these satellites that give us a grandstand global view of things like climate change. The final strand in all this is the presence of humans in space, which, apart from the Apollo astronauts reaching the moon in the late 1960s, has been confined to Earth orbit. Indeed, current activity is focused on the development of the International Space Station (ISS) in Earth orbit. When completed around 2010, the ISS will be the largest space structure ever built, weighing about 450 metric tonnes. However, many people look back at the



Apollo era and regard that as the golden age of spaceflight. As a consequence, the young people of today who are embarking on their careers not only have missed the main event, but also have not had the benefit of the inspiration that the Apollo era provided people of my generation. The moon landings were going on when I was in high school, and I have to say that Apollo was another reason (along with Mrs. Christian) why I chose to pursue a career in the space sector. Having said all that, it does seem that we are on the threshold of a new beginning for human space exploration. The planned retirement of the U.S. space shuttle fleet around 2010 is forcing a rethinking of American priorities in space, leading to the development of a program to return to the moon, and go on to land people on Mars within the next 30 years. This activity is also spurred on by the declared intention of other nations to return to the moon before 2020. This book is a distillation of the knowledge and experience that I have acquired over my 30-year career in space. My main motivation is to share my enthusiasm with general readers, not just readers with a technical education. I have attempted to discuss all aspects of how spacecraft work, but in a way that is accessible to people who have an active interest in space but who do not have the scientific and mathematical background to understand the plethora of technical books that are available on this topic. I hope this book satisfies that interest and helps readers learn more about this truly fascinating subject. The book discusses orbits, orbital motion, and weightlessness; how spacecraft are designed and how they work; and the likely developments in spaceflight in the 21st century, as well as a more speculative glimpse into the longer-term future of interstellar travel. The book requires no prior knowledge on the part of the reader. There are no mathematical equations, and I have tried to explain everything in an understandable and physically intuitive way, although in a few cases I have had to simplify and generalize for the sake of clarity. The average reader with a nontechnical background will find the text comprehensible, challenging, and, I hope, enjoyable. The idea of writing a book on spaceflight without resorting to mathematical equations arose from my involvement in short course teaching at the University of Southampton in England. Alongside all the teaching, research, and administration that are a normal part of a university academic's job, I have also been very much involved in professional development courses. Essentially, these are short training courses on space systems engineering, typically lasting 5 days or so, which we offer to professional engineers and scientists. Over the last 20 years, the European Space Agency (ESA) has been a principal customer in this business, and it



has been a privilege over this period to visit ESTEC (ESA's technical headquarters at Noordwijk, The Netherlands) on many occasions as a course organizer and a lecturer. Usually these courses are attended by ESA staff members with a strong technical background, but in about 1995 the training department at ESTEC requested a new type of training program: a space engineering course for nontechnical staff! This was a radical departure from our usual training activity. But the ESA wanted to train its nontechnical employees, such as lawyers, accountants, contracts staff, and secretaries, in the technical aspects of the business in which they are involved to increase their motivation and productivityÐa very enlightened training strategy. Over the years, this course has become very popular with ESA staff, being offered at a number of ESA venues across Europe. For us, the trainers, it posed significant challenges, in that we needed to put across to the delegates how spacecraft work without relying on prior technical knowledge or resorting to the use of mathematics. Meeting these challenges has been very rewarding, in terms of the appreciation of the course delegates, who have found a new fascination in learning how spacecraft fly. My wish is that readers of this book will find similar rewards. This book is dedicated to John Preston, a dear friend who died in March 2007. Despite being very ill, John spent much time helping me by reviewing a partial manuscript of this book, which says so much about him as a person. Even John would have agreed that he was not a scientist. Having his view on the text, as someone steeped in the humanities, was particularly useful in helping me craft the text for people without a technical education. One technical note: metric units of measure are followed by imperial units in parentheses, for the convenience of the reader. There is one exception: although a metric tonne differs from an imperial ton, which is the measure used in the United States (a metric tonne equals 1.102 imperial tons), the difference is slight, so the corresponding ton equivalent is not given. Graham Swinerd Southampton, England October 2007


The writing of this book has taken longer than I anticipated, and there are many people who have helped directly and indirectly in the writing of it. I would like to thank: John Preston and Stephen Webb for their reviews of the manuscript. All the people at the publisher Praxis, but in particular Clive Horwood, for his continued encouragement and guidance for a rookie author. My colleagues at the University at Southampton, especially the members of the Astronautics Research GroupÐAdrian Tatnall, Hugh Lewis, Guglielmo Aglietti, and Stephen Gabriel; of this group special thanks are due to Adrian, who has been a constant source of encouragement over my 20-year career at the university, and to Hugh, who has become a very supportive research partner in recent years. Frank Danesy, who was Head of Recruitment and Training at ESTEC during the mid-1990s; the space engineering course for nontechnical staff at ESTEC, which gave rise to the idea for this book, was his brain-child. Mrs. Christian, the elementary school teacher who set me off on the path of my lifelong love of ``everything space.'' My mother and my father (who died in 1995), who have supported me wholeheartedly at every twist and turn in my life's journey. My children, Vicky and Jamie, for blessing and enriching my life beyond all measure. Last, but not least, my wife, Marion, who has been by my side at every twist and turn, and who has always been my rock.


Foreword Preface Acknowledgments

vii ix xiii

1 2 3 4 5 6 7 8 9 10 11

1 23 49 69 91 115 143 157 171 211 245

A Brief History of Space Basic Orbits Real Orbits Beyond Circles and Ellipses Getting to Orbit Something About Environment Spacecraft Design Subsystem Design: I Like Your Attitude More Subsystem Design Space in the 21st Century Space: The Final Frontier?



A Brief History of Space


A Primitive Model of the Universe WE live in a world where it is difficult to extract ourselves from what might be called the collective knowledge of the human race. We are surrounded by huge information banks storing the collected thoughts of the clever people who have shaped the way we think about the world. Among these resources we can include our own education from our earliest years. In addition, we have the written word, the spoken word through television and radio, and access to the World Wide Web, which provides a view of the world through cyberspace. As a consequence of this immersion in collective knowledge, most of us have an idea of the structure and workings of the solar system, and the universe in general, without ever having to venture beyond our armchair. It is very difficult, therefore, to put ourselves in the position of ancient man, who looked up at the sky with unsophisticated and unaided eyes, and attempted to make sense of it. If you could take this leap backward a few thousand years, and at the same time leave behind your collective knowledge, what would you make of it all? I would guess that only a minority of your friends and family would be interested anyway. Times were hard, and most of us would probably have spent the majority of our time just surviving. However, let's suppose that you were able to retain a few brain cells for things other than where your next meal was coming from. Perhaps the first obvious feature of your model of the universe would be a clear belief that the world was flat. If you look out of the window now, it does look flat, doesn't it? You wouldn't have needed to be too clever to notice that the Sun and Moon make a daily journey across the sky, from horizon to horizon in about 12 hours. If you were also a bit of an ancient astronomer, interested in the night sky, you also might have noticed that this daily journey is shared by the stars. You would have to be really observant, however, to have noticed that some of the brighter starsÐwhat we now call the planetsÐwander among the fixed stars over a longer time scale. What sort of model would you have dreamed up, as an ancient person, G. Swinerd, How Spacecraft Fly: Spaceflight W ithout Formulae, DOI: 10.1007/978-0-387-76572-3_1, © Praxis Publishing, Ltd. 2008



How Spacecraft Fly

deprived of your collective knowledge? A sensible picture would be what might be called the ``primitive'' modelÐthat the universe of Sun, Moon, and stars rotated about the flat Earth once every day. This flat Earth±centered model was indeed the accepted one for a long time, simply because it seems the obvious interpretation of what we see around us. How we have moved on from this model to our current understanding of how the universe works is a well-documented but long and winding pathway through the history of science. Periodically, over time, a gifted individual has joined the journey along the pathway to challenge the accepted view. It is not the intention of this chapter to give a detailed account of this journey, but rather to look at some of the more important milestones, and to discuss some of the individuals who have made important contributions to the story.

Flat Earth to Spherical Earth As we can see from the above, interestingly, ancient and modern civilizations can have widely different interpretations of the way things work, even though they both see the same sky. Generally, the differences occur as a consequence of the precision of observation that can be achieved using the unaided eye thousands of years ago compared to using powerful telescopes today. The first substantive attack on our primitive model is credited to Eratosthenes, who lived in the ancient Egyptian city of Alexandria around 300 B.C. He used an astonishingly simple method, developed by a sharp intellect, to estimate the size of the spherical Earth, having first disregarded the belief that the Earth was flat. The basics of the method are illustrated in Figure 1.1a. Eratosthenes was somehow aware that at around the time of midsummer, vertical posts did not cast shadows at noon in Syene (point A), which is in a region of southern Egypt traversed by what we now call the Tropic of Cancer. However, at the same time of year and day, he could see that vertical posts in Alexandria (point B) did cast shadows. This supported the idea in his mind that the Earth was not flat, but sphericalÐan extraordinary leap of logic. He was also aware, using the geometry shown in Figure 1.1a, that the simple measurements of the angle a, and the distance between Alexandria and Syene, would allow him to measure the circumference of his now spherical world. The distance measurement was simple in principle, but arduous in practice, as he had to employ someone to pace out the 800 km (500 miles) or so between the two centers! His estimate of Earth's circumference was around 40,000 km (25,000 miles), which is amazingly close to our modern estimate of 40,075 km (24,903 miles).

A Brief History of Space


Eratosthenes is remembered today for his ingenuity and vision, but also because he was right. It does make you wonder, though, how many of his fellow Alexandrians believed in his claims of a spherical EarthÐsomething a bit hard to swallow for the average man in the street at that time. In order to draw his conclusion, he needed to assume not only that Earth was spherical, but also that the Sun was a long way away from Earth so that the sunlight illuminated Earth's surface with effectively parallel rays (Fig. 1.1a). An equally good interpretation of his observation of shadow lengths at noon is illustrated in Figure 1.1b, which would probably have gone down better with

Figure 1.1: Alternative interpretations of Eratosthenes's observations of shadows cast by vertical posts at widely separated locations.


How Spacecraft Fly

his contemporaries. If the Sun is assumed to be closer to Earth, so that the divergence of its rays is apparent, then the flat-Earth model can be saved. Over time, however, Eratosthenes was shown to be right, and the first cornerstone of our primitive model of the universe crumbled.

Earth-Centered to Sun-Centered Universe The idea of an Earth-centered universe was firmly established by Claudius Ptolemaeus, known more commonly as Ptolemy, in the second century A.D. Ptolemy's universe had Eratosthenes's spherical Earth at its center, around which moved the Sun, Moon, planets, and stars. It was inconceivable that man, God's favored creation, should live anywhere other than at the center of the cosmos! Furthermore, by similar reasoning, it was supposed that these heavenly bodies, far removed from the imperfections of earthly life, should move along perfect circular paths. However, there were problems with the model, which even the astronomers in Ptolemy's time could detect with their limited observational capabilities. The planets had been discovered centuries beforeÐthe Romans worshiped them as godsÐand they could be distinguished not only by their brightness, but also by their movement across the sky relative to the fixed stars. Mars in particular appeared to challenge Ptolemy's model by moving erratically, performing loops in its motion among the stars, as shown in Figure 1.2. Ptolemy struggled to explain this behavior by introducing epicycles into his model. An epicycle is essentially a smaller circle around which a planet moves, which in turn is superimposed upon the larger circle representing the planet's motion about Earth. Throughout his lifetime, Ptolemy continued to tweak his model, introducing many epicycles in an attempt to fit observations. Despite its evident weaknesses, the Earth-centered model survived for 1300 years or so, primarily because of the power and influence of the Church over this period. To challenge the notion that Earth was the center of the universe would have been considered foolhardy, a crime against God that could attract the severest penalty. The person credited with making this challenge was Nicolaus Copernicus, a Polish Catholic cleric who was born in 1473. The main feature of Copernicus's universe was that he relegated Earth to be just one of a number of planets orbiting the Sun. At the time, this Sun-centered model was an extraordinary shift in our worldview, but Copernicus boldly swept away the old ideas, writing explicitly about the inadequacy of the previous arguments and refuting them. Copernicus waited until the year of his death, 1543,

Figure 1.2: The apparent looping motion of Mars, relative to the fixed stars, as seen over a period of a few weeks.

A Brief History of Space



How Spacecraft Fly

before going public, presumably to avoid the consequences of religious persecution. Unkind contemporaries of Copernicus labeled him the ``restorer'' of the Sun-centered universe, in deference to Aristarchus, who held this belief around 280 B.C. However, the world was not ready for this idea in the third century B.C. Copernicus is remembered not just for establishing the idea of a Sun-centered solar system; many other related contributions secure his place in history: . An understanding of the rising and setting of the heavenly bodies in terms of the daily rotation of the Earth. . An explanation of the seasons due to Earth's annual journey around the Sun. Copernicus deduced that Earth's spin axis was not perpendicular to the orbit plane. Consequently, the Northern Hemisphere would be tilted toward the Sun during the Northern Hemisphere's summer, and conversely tilted away during the winter months. . A mechanism to explain the looping motion of the planets among the fixed stars (Fig. 1.3). . The estimation of the size of the planets' orbits in ``astronomical units,'' and their periods (that is, the time taken to orbit the Sun). In this process, Copernicus assumed that the orbits were circular. The last item on this list was a staggering achievement, and deserves further attention. First of all, what is an astronomical unit (AU)? In modern terms, it is the average distance between Earth and the Sun, taking into account that the distance varies a bit as the Earth orbits the Sun. Numerically

Figure 1.3: Copernicus's explanation of the apparent looping motion of Mars among the fixed stars. He assumed that Earth and Mars moved along circular orbits with different periods, so that Earth moved from point 1 to point 5 in the same time that Mars moved from point A to point B.

A Brief History of Space


1 AU is around 150 million km (93 million miles). Copernicus had no way of determining this, but with careful thought he could devise ways of estimating the distance of the known planets from the Sun as multiples of the Earth-Sun distanceÐthat is, in astronomical units. Therefore, he was able to construct the scale of the known solar system relative to the size of Earth's orbit, but its absolute size escaped him. The explanation of his methods is a little complicated, but I hope the reader will come along for the ride! For the planets Mercury and Venus, closer to the Sun than Earth, the basics of this method are illustrated in Figure 1.4. Taking Venus as an example, Copernicus could observe its orbital motion around the Sun, as we can today, by watching its track in the sky at the time

Figure 1.4: (a) The motion of Venus in the evening sky over a period of weeks, allowing the measurement of the maximum angle (angle a) between the planet and the Sun. (b) The orbital geometry of Earth and Venus at the time of maximum angular separation.


How Spacecraft Fly

Figure 1.5: Copernicus estimated the radius RJ of Jupiter's orbit, again using `simple' trigonometry.

of sunset over a number of weeks (Fig. 1.4a). To estimate the size of the orbit, Copernicus just needed to note the maximum angle between the Sun and the planet over this period, and he could then translate this to the orbital geometry shown in Figure 1.4b. The problem then reduces to a simple one, involving solving the lengths of the sides of a right-angled triangle using trigonometry. Most readers will have come across trigonometry in school mathematics lessons and probably will have forgotten it! However, referring to the triangle in Figure 1.4b, all that needs to be understood is that if Earth's orbit radius (RE is 1 AU) and the maximum angle (angle a) are known, then the radius RV of Venus's orbit can be calculated. Adopting this simple process, Copernicus found that RV was approximately 0.7 AU, and a corresponding analysis of Mercury's motion gave its orbit radius as about 0.4 AU. The process for estimating the orbit sizes of the outer planets known to Copernicus (Mars, Jupiter, and Saturn) was a little more involved. There are a number of ways of looking at this, but they all boil down to the same thing, and ultimately reduce again to a simple trigonometrical problem.Taking the planet Jupiter as an example, Copernicus measured the time it took for Earth to ``lap'' Jupiter in their respective orbits. He noted that approximately every 400 days Jupiter returned to the same position, due south in the sky at midnight. Translating this into orbital position, he realized that this happened when Earth was precisely between the Sun and Jupiter, and was about to overtake Jupiter. He then went on to deduce that a quarter of this lapping periodÐapproximately 100 daysÐafter this alignment, Earth would be 90 degrees ahead of Jupiter in its orbit, giving the orbital geometry shown in Figure 1.5. The measurement of the angle between the Sun and Jupiter at

A Brief History of Space


this time, an observation best made at sunset, completed the puzzle and allowed Copernicus to calculate the radius of Jupiter's orbit at about 5.2 AU. Similar calculations gave estimates of the radii of Mars's and Saturn's orbit, at around 1.5 AU and 9.5 AU, respectively.

When Johannes Met Tycho Copernicus's work, containing a wealth of apparently irrefutable detail, put the Earth-centered universe to rest, and finally removed the constraints that had inhibited the quest to understand the solar system for over a millennium. The next person to make progress on this quest was Johannes Kepler, who was born in Germany in 1571. As a theoretician of the first order, he brought his intellect to bear upon Copernicus's model of the solar system, and found it lacking. However, Kepler knew that precise observations of the planets' motions were required in order to expose the weaknesses of Copernicus's model and make further progress along the pathway. This need was satisfied by Kepler's chance association with Tycho Brahe, a Danish nobleman who spent much of his life and resources developing an astronomical observatory on an island off the coast of Denmark. This housed precision instruments, and Tycho compiled what was the most complete and accurate catalogue of planetary position measurements available at that time. Johannes's brilliance as a theoretician and Tycho's observational genius complemented each other perfectly, to bring about the next revolution in understanding. However, their relationship was an uneasy one, and Tycho was reluctant to gift his life's work to a younger rival. Tycho did make his observations available to Kepler, but only in a frustratingly piecemeal manner. This impasse was finally resolved on the death of Tycho, after which Kepler was able to extract the full catalogue of measurements from Tycho's family. Now that Kepler had accurate observations, he spent a number of years trying unsuccessfully to reconcile them with the notion that planetary orbits were circular. Looking at the orbit of Mars, he struggled for nearly a year to resolve a discrepancy between observation and theory of only 8 minutes of arcÐa small angular measure of about one-quarter the diameter of the full moon. This in itself says a great deal about Kepler's integrity and honesty; clearly, it would have been easier to ignore such a small anomaly, or to regard it as an erroneous measurement. This struggle, however, led Kepler to the idea that was to be his core contribution to the understanding of the solar systemÐthat planetary orbits were elliptical in shape. Making this


How Spacecraft Fly

step, he now found that Tycho's measurements fitted beautifully, and thereafter Kepler published his first two laws of planetary motion in 1609. His third law, to do with the relationship between the size of an orbit and its period, was also a tough one that took him a further 10 years to establish. Kepler's three laws of planetary motion are as follows (see also Figure 1.7): Kepler 1 ± The orbit of each planet is an ellipse, with the Sun at one focus. Kepler 2 ± The line joining each planet to the Sun sweeps out equal areas in equal times. Kepler 3 ± The square of the period of a planet is proportional to the cube of its mean distance from the Sun. It is worth dwelling a few moments on Kepler's laws, to explain the jargon, and to illustrate their meaning. The first law uses the word ellipse, which from high school geometry could be described as egg-shaped or a squashed

Figure 1.6: Drawing an ellipse. The ellipse's focal positions are where the pins penetrate the card.

Figure 1.7: Illustrations of (a) Kepler's first law and (b) his second law.

A Brief History of Space


circle. We know that to draw a circle, we use a compass. The resulting figure has one focusÐthe center where the point of the compass penetrates the paper. You may also have drawn an ellipse in school by pressing two pins into a piece of card, and placing a loose loop of string around the pins. Placing a pencil in the loop, and keeping the string tight, we can move the tip of the pencil over the paper to produce an ellipse, as shown in Figure 1.6. The two points where the pins penetrate are referred to as the focuses of the ellipse. From Kepler's first law (refer to Fig. 1.7a), we see that planets move along elliptical orbits, but also that the Sun is located at one of the focal positions. Kepler's second law is a rather strange way of describing how fast a planet moves at different points on its orbit. Looking at Figure 1.7b, we can see that if a planet moves from point 1 to 2 in the same time that it takes to move from point 3 to 4, then Kepler's second law implies that the shaded areasÐ Area 1 and Area 2Ðmust be equal to one another. This geometrical argument can be translated into a dynamical one, since it is easy to see that, for this to happen, the planet must move rapidly when close to the Sun, and more slowly when further away. Kepler's 17th century mind tended to think in terms of geometry, whereas a modern orbit analyst would tend to take the dynamical view.Kepler expressed his third law in terms of a word equation, and since we are trying to avoid the use of equations it is sufficient to say that planets in big orbits take longer to orbit the Sun than planets in small orbitsÐa fairly commonsensical notion. Trying to summarize Kepler's activities in a few paragraphs, as we have done here, does no justice to the magnitude of his achievement in establishing the modern view of the way the planets move around the Sun. The time he took to do this does, perhaps, give a measure of the difficulty of the task. His achievement is emphasized by noting that his laws are still used today when engineers analyze the motion of spacecraft around the Sun, or indeed the orbit of a satellite around the Earth. It is also important to realize that Kepler developed his laws empirically, based purely on Tycho's catalogue of planetary measurements. He described how the planets moved around the Sun, but had no underlying theoretical foundation to explain why they moved in this way. This task was left to the intellectual giant that was Isaac Newton.

``On the Shoulders of Giants . . .'' Newton was born on Christmas Day 1642, just 23 years after Kepler had published the last of his three lawsÐand what a gift to the world! Newton


How Spacecraft Fly

has been described in clicheÂd terms by numerous biographers: ``the foremost scientific intellect of all time''; ``the father of modern science''; and so on. However, when applied to Newton, these glowing epithets are arguably fully justified. Newton made major contributions to many areas of scientific activity, including optics and light, mathematics, dynamics, gravitation, and theoretical astronomy. He himself, however, summarized his contribution to science by stating, ``If I have been able to see further, it was only because I stood on the shoulders of giants,'' referring to some of those giants discussed in the preceding sections of this chapter. Newton's quest to understand the world began with his undergraduate career at Trinity College, Cambridge University, at the age of 18. However, his time at Cambridge was interrupted in the summer of 1665, when the university was closed down by an outbreak of plague. Newton then returned to his birthplace, the isolated village of Woolsthorpe in Lincolnshire, where in an amazingly productive period of 2 years he revolutionized science. In summary, during this period he devised his law of gravitation and his laws of motion. Combining these, he was able to formulate the equations that governed the motion of the planets around the Sun. He then realized that these equations could not be solved using the methods then available. However, he was not a person to let such a small detail inhibit his efforts, and so he set about inventing a new branch of mathematics, called calculus, to remove the barrier. All of these accomplishments have had a lasting impact upon science and engineering to the present day, and any one of them would be considered a major intellectual achievement. For them all to have come from one individual in such a short period of time is extraordinary. It is worth pausing a few moments to consider in more detail each of the steps that comprised Newton's achievement. Perhaps the thing most people associate with Newton is his law of gravitation, along with the story of the mythical apple that is supposed to have fallen on his head and given spontaneous birth to the idea. It is likely, however, that the formulation of his understanding of gravity took a little more time and effort. The formal statement of Newton's law of gravitation is given below, and as can be seen it is expressed once again as what might be called a word equation: Newton's Law of Universal Gravitation ± the force of gravity between two bodies is directly proportional to the product of their masses, and inversely proportional to the square of their distance apart. However, it can be easily understood in simple terms. The phrase ``directly proportional to the product of their masses'' simply means that the force of gravity between two large objectsÐsay two planets, or two starsÐis large, and indeed will govern the way these celestial bodies move with respect to

A Brief History of Space


each other. On the other hand, the force of gravity between two small objects will be tiny. For example, if you place a couple of balls on a pool table, you expect them to remain firmly attached to the surface, since they are attracted to the large mass which is the Earth beneath the table. It is only the structural strength of the table that is preventing them from responding to the force by whizzing off toward Earth's center. At the same time, we do not expect them to move across the table toward each other, since the force of gravity between them is so small as to be effectively zero. The game of pool would be somewhat different if it were otherwise! The way the force of gravity varies with distance, as described above, is sometimes referred to as the inverse square law. This describes how the force between two bodies diminishes as they move further apart. If you think of two objects a particular distance apartÐstrictly this distance is measured between their centersÐthen the force of gravity between them will have a particular strength. When we move them apart so that the distance between them is doubled, the inverse square law says that the force is one fourth of what it was before. To get this, we take 2 from ``twice the distance,'' square it to give 4, and then take the inverse to give us the one fourth. In the same way, we can move the bodies 10 times further apart, and the same argument tells us that the force of gravity is reduced by a factor of 1¤100. There is some debate among scientific historians about how Newton settled upon the inverse square law for gravitation. Some believe he was influenced by his studies of the way light behaved; he discovered by experiment that the intensity of light falling upon a surface decreased in proportion to the inverse square of the distance between the source of light and the surface. However, more likely he proposed the inverse square law since it was consistent with Kepler's third law of planetary motion, which can be shown by the use of some simple mathematics that can be done literally on the back of an envelope. Coming back to Newton's apple, we can explore some of Newton's thinking during his brief but prolific period of exile in the Lincolnshire countryside. Having thought about his law of gravitation in a universal context, Newton's observation of the fall of an apple from a tree engendered universal questions in his mind such as, Why doesn't the moon also fall to the ground? To answer this one, we can compare the motion of the apple with that of the moon. Taking the apple first, when it is released from the tree it responds to the force of gravity by accelerating toward the ground. It starts from rest up in the branches of the tree and builds up speed until impact with the ground. If we were able somehow to measure this impact speed and the time of fall, we


How Spacecraft Fly

would be able to calculate its acceleration. For example, if the height of the tree was such that the apple took 1 second to hit the ground, we would find that its impact speed was about 10 meters per second (32 feet per second). In this case, the distance fallen can be estimated as about 5 meters (16 feet)Ð quite a tall apple tree. If the ground were not in the way, the apple would continue to accelerate toward Earth's center, gaining 10 meters per second in speed for every second of the fall. This acceleration due to gravity at Earth's surface of 10 meters per second per second is usually expressed as 10 m/sec/ sec or 10 m/sec2 (32 feet/sec2). Newton was the first to realize that the moon must also respond to the force of gravity in the same way. However, the moon is around 60 times more distant from Earth's center than his apple. Applying his law of gravitation, he estimated that the acceleration of the moon toward the Earth will be much less than that of the apple by a factor of 1¤3600Ðthat is, the inverse of 60 squared. In its distant orbit then, the moon will fall toward Earth with an acceleration of approximately 10/3600 meters per second per second, or about 3 millimeters/sec2 (1¤100 feet/sec2). With this small acceleration downward, it is easy to estimate that in 1 second the moon falls a small distance toward Earth of about 1.5 millimetersÐmuch less than the 5 meters fallen by the apple. However, it is instructive to consider what happens to the moon's motion during the period of a minute, as then the numbers are a little easier to grasp. Because of the coincidence that the moon is 60 times further away from Earth's center than the apple, and that there are 60 seconds in a minute, the mathematics tell us that the moon falls the same distance in 1 minute as the apple falls in 1 secondÐabout 5 m. However, at the same time the moon has a relatively high speed along its orbit so that in 60 seconds it moves horizontally approximately 61,100 meters (200,500 feet). Figure 1.8 shows that the combination of these horizontal and vertical motions result in the near-circular orbital path that we observe, so that although the moon does actually fall continually toward Earth, fortunately it never reaches the ground! To understand the motion of bodies, such as the apple and the moon, in this way, Newton had to devise not only his universal law of gravitation, but also his three laws of motion, which are stated as follows: Newton 1 ± A body will continue in a state of rest, or of uniform speed in a straight line, unless compelled to change this state by forces acting upon it. Newton 2 ± The rate of change of momentum of a body is proportional to the force acting upon it, and is in the same direction as the force. Newton 3 ± To every action there is an equal and opposite reaction.

A Brief History of Space


Figure 1.8: Newton applied his universal law of gravitation to the Moon, as well as to his apple, to show how the Moon orbits Earth.

It is important to note that these laws, written in the form of words here, have their most powerful manifestation when expressed in mathematics. They revolutionized 17th century science, and indeed still dominate engineering science today. Newton's contribution is summed up by noting that 21st century engineers still use the mathematical expression of these laws to design buildings, bridges, cars, airplanes, and indeed spacecraft. I would love to stand with Isaac Newton at the end of a modern airport runway as a jumbo jet is taking off, and tell him that he is responsible for this apparently impossible apparition of 350 metric tonnes of predominately metal soaring into the skyÐan amazing legacy! In terms of our understanding of the solar system, Newton's revolution came about when he combined his law of gravitation with his laws of motion to produce equations that described the motion of the planets around the Sun. As described earlier, the solutions of these equations were obtained only after Newton had devised a new branch of mathematics. But once this was done, Newton rediscovered Kepler's three laws of planetary motion in his mathematics, thus giving a theoretical basis to Kepler's empirical work completed almost half a century before. However, Newton found not only Kepler's work in his new formulism but lots more. His mathematics were saying that objects moving in a gravity field, for example, a planet moving around the Sun, or a spacecraft moving around a planet, were not confined to elliptical paths. The shape of the path of such an object could also be that of a circle, a parabola, or a hyperbola. Most people are familiar with circles and ellipses, but what about the parabolic and hyperbolic shapes? These four shapes are referred to as conic sections,


How Spacecraft Fly

Figure 1.9: The shapes of orbital trajectories can be obtained by slicing a cone.

because you can get them by sectioning, or slicing, a cone as illustrated in Figures 1.9 and 1.10. In Figure 1.9a, we can see that if we slice the cone horizontally we get a circle, and if we slice it slightly obliquely we get an ellipse. Another trajectory shape is obtained by slicing the cone in such a way that the plane of the slice is parallel to the side of the cone, as in Figure 1.9b. In this case we get a parabola. The parabolic trajectory is not a closed oneÐas are the circle and ellipseÐso we have to imagine that the cone is infinitely big, and not truncated at the base as illustrated. An example of an object on a parabolic trajectory is a comet that falls with initially zero speed from infinityÐor effectively from a great distanceÐand is swung around the Sun and ends up heading back to the same place, arriving again at infinity with zero speed. Perhaps this type of trajectory can best be describes as a celestial U-turn. The final trajectory shape that Newton found in his mathematics is the hyperbola, which is obtained by slicing our cone vertically, as shown in Figure 1.9c. This trajectory is again an open one, stretching to infinity, so we have to imagine that our cone is very large. An example of this type of orbit is a spacecraft swinging by a planet. The spacecraft approaches from great distance, initially traveling at constant speed relative to the planet in a straight line, as the gravitational influence of the planet is tiny. However, as the spacecraft closes in, the gravitational force increases and the trajectory is deflected. The gravity of the planet swings the spacecraft's path around so that the vehicle leaves the planet in a new direction, traveling in a straight path again at the same planet-relative speed once it has reached great distance. As we will see later in Chapter 4, this type of swing-by trajectory is commonly used by engineers designing interplanetary spacecraft missions. The hyperbola is distinguished from the parabola by the deflection angle; in a parabolic trajectory the object is deflected by 180 degrees by its encounter

A Brief History of Space


Figure 1.10: The light cast by a table lamp shows the hyperbola-shaped, swing-by trajectory of a spacecraft.

with the planet, whereas the hyperbolic trajectory is deflected by an amount less than this. Surprisingly, the hyperbola is also a fairly common sight in everyday life. All you need is a lamp with a circular shade, which projects a cone of light both upward and downward, producing a circle of light on the ceiling above and on the table below. If, however, the lamp is placed next to a wall, then the cone of light is effectively sliced vertically, as in Figure 1.9c, to produce the shape of a hyperbolic trajectory on the wall. A photograph of such a shape is shown in Figure 1.10a, and how it relates to the orbital trajectory is shown in Figure 1.10b. If you find yourself on a dinner date in a restaurant with this common type of wall lighting, you could use your knowledge of celestial


How Spacecraft Fly

mechanics to break the ice. (On the other hand, your guest may just think that you are a rather sad person who needs to get out more!) Newton himself thought of his scientific investigations as a small contribution toward revealing the fundamental laws of the universe that were ``written'' by God, its designer. Thinking about his discoveries in this context, it is rather strange that we live in a universe where the shapes of gravitational trajectories are related to slices of a cone! The final episode in this story of Newton's achievement is also surprising. Having ``solved the universe'' in this way, Newton then failed to communicate his work to anyone! Meanwhile, unknown to him, contemporary scientistsÐ principally Robert Hooke and Edmund Halley (of Halley's Comet fame)Ð were struggling with the problem of planetary motion in the coffee houses of London. Finally in 1684, Halley visited Newton in Cambridge, hoping to gain some insight into the riddle. When Halley posed the question about the shape of gravitational trajectories about the Sun, Newton revealed that he had already solved the problem, but had characteristically misplaced it. It was ultimately Halley who encouraged Newton to write his landmark work, the Philosophiae Naturalis Principia Mathematica, requiring 2 years of hard work to complete. In this rather circuitous manner, Newton was finally recognized as being one of the greatest scientific thinkers of all time. The only other individual described is this way is perhaps Albert Einstein, whose scientific genius was unleashed upon the world at the beginning of the 20th century.

What Did Einstein Do for Us? Einstein's contribution was fundamental and profound, a revolution in the way we think about the physics of motion, and in particular the motion of bodies in a gravitational field. This revolution began with the publication of Einstein's special theory of relativity in 1905, when Newtonian physics was well established, and most scientists believed their understanding of the physical laws of nature was complete. After all, newtonian physics had reigned supreme for something like 220 years! This blow to the scientific establishment was all the harder to take, as Einstein's interest in physics was a hobby at the time; his job was that of a patent clerk in an office in Berne. However, his new physics took the scientific community by storm. A cornerstone of Einstein's work was an appreciation that the arena in which all physical events take place is a four-dimensional world called spacetime. In other words, to describe the location of a physical eventÐfor example, the impact of an apple on the groundÐwe need four numbers,

A Brief History of Space


three defining its position in space, and another giving the time. In Newton's physics the three-dimensional spatial world and time were considered to be independent and absolute. However, in Einstein's theory, space and time are inseparably interwoven, and the place and time defining an event are not absolute but depend on the state of motion of the observer. This rather strange notion led to the uncomfortable idea that Newton's physics was incorrect; however, the differences between Newton's and Einstein's descriptions of the world manifested themselves only when things moved at very high speeds, that is, speeds near the speed of light of 300,000 km per second (186,000 miles per second). Einstein's revolution was not complete, however, as in 1916 he published his theory of gravitationÐthe general theory of relativity. The journey from the special theory to the general was not an easy one, and Einstein struggled with the physics and, in particular, the mathematics required to formulate his gravitational theory. Indeed, the mathematics required to describe his theory of gravity were so complex that it was claimed that few people in the world actually understood it when first published. Fortunately, the principles of the theory can be explained in relatively simple terms. Einstein's description of the way planets moved around the Sun is completely different from Newton's view. In Einstein's theory, the fourdimension world of space-time is not just a background reference system against which the locations and timings of physical events are recorded, but rather it becomes a dynamic entity, playing a central role in the way things move in a gravity field. The underlying principle of Einstein's general theory is that massive objects, like the Sun, distort the geometry of space-time. This is the famous warped space, which has become so familiar to us all, courtesy of popular science-fiction epics like Star Trek. However, although we have heard a lot about it in sci-fi stories, nevertheless an appreciation of what a curved four-dimensional space-time continuum means is very difficult to grasp, even for those equipped to understand the mathematics! Einstein's basic idea of motion in a gravity field is that objects move in such a way as to take a path that gives the shortest distance between two points. Clearly in our everyday experience, the path defining the shortest distance between two points is a straight line. But then, in our everyday experience, we do not often come across warped space! However, there is one everyday example of determining the shortest distance between two points in a curved spaceÐthat is, the efficient global routing of aircraft. For example, what is the shortest distance between London and Sydney in the curved two-dimensional space we call Earth's surface? If we take a map and just draw a straight line between London and Sydney (the broken line in Figure 1.11), we find that this is not the shortest


How Spacecraft Fly

route. The shortest route can be found by stretching a piece of string on a globe, holding down the ends over London and Sydney. If you then plot this route on a map (the continuous line in Figure 1.11), you will find that the shortest route is curved. A quick experiment with a globe and a piece of string will help you to check this. Returning to Einstein's gravity, as we said above, the influence of the massive Sun is to produce curvature in the fabric of space-time surrounding it. Straight lines in this space are no longer straight, but curve along the contours of the warped space produced by the Sun. The resulting orbital trajectories are effectively those found by Kepler and Newton. Given this, the reader might ask why Einstein's complex theory of gravity is needed, when Newton does a perfectly good job already. The answer is that Einstein's theory goes further, and predicts additional effects that are particularly conspicuous in very intense gravitational fields. A good example of this is the bending of light as it passes the Sun, an experimentally confirmed effect that is not predicted at all by Newton's theory. In our everyday experience, a beam of light is perhaps the best way of defining a straight line. However, in

Figure 1.11: In the curved two-dimensional space of Earth's surface, the shortest distance is not a straight line.

A Brief History of Space


the warped space surrounding the Sun, the path of the light is deflected (very slightly) in response to the curvature of space-time. Another curious feature of Einstein's general theory is that when space-time is curved by the presence of a massive object, not only are the spatial dimensions curved, but the time dimension is as well; we are presented with the bizarre notion that clocks run at different rates depending on how close they are to the object! Clearly Einstein's achievements are pertinent to our story, but we should return to the question in the title of this section: What did Einstein do for us? Well, if the ``us'' refers to spacecraft design engineers, the honest answer is ``not a lot!'' The spacecraft missions achieved in the first half century or so of the Space Age involve space vehicles that have not achieved very high speeds, compared to the speed of light. Similarly our activities have effectively been confined to the region of space near the Sun, where very intense gravitational fields are not encountered. As a consequence, the more exotic effects of Einstein's theory do not manifest themselves, and we are left with the rather surprising conclusion that modern spacecraft engineers still use 300-year-old Newtonian theory. There is, however, one clear example where Einstein's relativity theory does make an essential contribution to the design of a spacecraft. The U.S. Department of Defense operates a space system called Navstar Global Positioning System (GPS), which is used as a navigational aid for all branches of the U.S. armed forces. However, a lot of people reading this may have used GPS for leisure purposesÐhiking, sailing, or flyingÐor for in-car navigation. The space system comprises a constellation of 24 satellites in near-circular orbits at heights of around 20,500 km (12,700 miles). If you have an appropriate receiver on the ground, the system will provide information about your location accurate to about 10 meters in each of the three spatial dimensions. To do this, however, each satellite must carry an atomic clock, which needs to be accurateÐto about one second in every 30,000 years or so! To do the necessary calculations to find your position on the ground, your receiver must also have a clock. Fortunately, this clock need not be quite so sophisticated (or expensive!) as the satellite clocks, but it should record the passage of time at the same rate as the orbiting clock, during the short period when the receiver is doing its calculations to estimate where you are. However, the receiver clock on the ground is a lot closer to the gravitational mass of Earth than the satellite clock, and therefore Einstein said the ground clock will run slower than the orbiting clock. Over the period of a day, the combined effects of Einstein's theory cause an accumulated error of around 38 microseconds (38 millionths of a second) difference between the orbiting and ground clocks. Although this sounds small, when translated into a navigational error it amounts to about


How Spacecraft Fly

10 km. After a day your in-car navigation system might be indicating that you are in the wrong town! When the first experimental GPS satellite was launched, some engineers were skeptical about the importance of the Einstein effects, but soon realized that time warping is a reality. To overcome this problem in the current spacecraft design, the satellite clocks are manufactured with an appropriate offset in the clock rate built in. How we have come to understand space is a rather intriguing story, and what I have presented here is an abbreviated and personal view of something that could have a whole book devoted to it. In summary, perhaps one of the most surprising conclusions to be drawn from this discussion is that modern spacecraft engineers still predominantly use Newtonian theory to design spacecraft, and to design the orbits they travel to achieve a particular destination. We will take this notion forward in subsequent chapters, where the way spacecraft are designed is discussed in more detail.

Basic Orbits


How Spacecraft Move in Orbit BEFORE getting to the business of discussing the orbital aspects of modern spacecraft missions later in this chapter, there are a few fundamentals about the orbital motion of a spacecraft that we need to discuss, and a few popular misconceptions about it that need to be put to rest. The first of these fundamentals is how a spacecraft remains in orbit around Earth, effectively forever, without having to fire rockets to sustain the motion. The answer lies in understanding that the spacecraft, like a stone falling down a deep well, is in a state of continual free-fall. Clearly, we do not expect the stone's motion to be assisted by rockets; it just falls unaided in the gravity field until it impacts the water at the bottom of the well. Free-fall in a gravity field is also the key to understanding the spacecraft's motion, although in this case it is perhaps not so apparent. And, of course, the spacecraft operator hopes that, in the process, it does not impact the ground like the stone! To help with this discussion, we turn to a device that has become known as Newton's cannon, after its originator Isaac Newton. He first introduced the idea around 1680 in ATreatise of the System of the World, which he wrote as a popularization of his great work the Principia (see Chapter 1). Newton produced a diagram of his cannon in his treatise similar to that in Figure 2.1. To start with we have to imagine an impossibly high mountain, let's say 200 km (124 miles) high, for the sake of argumentÐa real challenge to the climbing fraternity. Not only is it a long way to the top, but when you get there you are effectively in the vacuum of space. Then you have to envisage dragging all the materials necessary to the summit to build a large cannon there that is capable of firing projectiles at a range of barrel speeds. This is also illustrated rather unimaginatively in Figure 2.1. The cannon crew, presumably all dressed in space suits, now begins the serious business of firing cannonballs at the unsuspecting population below. You can see that if the crew fires a cannonball out of the gun with a barrel speed of, say, 2 km/sec (1.24 miles/sec), then it will do as you expect it to ± G. Swinerd, How Spacecraft Fly: Spaceflight W ithout Formulae, DOI: 10.1007/978-0-387-76572-3_2, © Praxis Publishing, Ltd. 2008



How Spacecraft Fly

Figure 2.1: Newton's cannonÐa ``thought experiment'' devised by Isaac Newton to explain the nature of orbital motion.

that is, take a curved path and impact the ground some distance away at point A (Figure 2.1). If the barrel speed is then ramped up to, say, 6 km/sec (3.73 miles/sec), the cannonball becomes intercontinental and travels a whole lot further to point B before impacting Earth's surface. However, something really interesting happens when the crew further increase the barrel speed to around 8 km/sec (5 miles/sec). Now the cannonball's path curves toward Earth's surface once again, but the curvature of the trajectory is matched by the curvature of Earth, and the ball continues to fall toward Earth without actually making contact! The projectile has now entered a circular orbit around Earth (Figure 2.1), and the cannon crew had better watch out as the ball will whizz past the gun about 90 minutes later, after making a complete orbit of Earth. Like the stone, the ball is now in a state of free-fall, and will continue to orbit Earth indefinitely. To reinforce this idea, we can look at the same situation but consider Earth's curvature. At the mountain summit, the curvature is such that Earth's surface falls away below a truly flat horizontal plane by about 5 m (16 ft) in approximately every 8 km (5 miles) traveled over the ground. You may also recall that 5 m is roughly the distance fallen by Newton's apple in 1 second (Chapter 1). If you fire a cannonball from the gun at an initially horizontal

Basic Orbits


speed of around 8 km/sec, it too will fall 5 m in the first second of flight, thus matching Earth's curvature. Therefore, no ground impact results, and you have orbital motion. To be more precise, for the cannonball to enter a circular orbit, it must be fired at a speed of 7.78 km/sec (4.84 miles/sec) from the summit cannon. For those of you who like more familiar units, this is about 28,000 km per hour (17,400 mph), which is a typical speed for a space shuttle in low orbit. Newton's other orbital trajectories (Chapter 1) can also be produced using the summit cannon. For example, if we further increase the barrel speed to around, say, 9 km/sec (5.59 miles/sec), this has the effect of raising the height of the ball's trajectory on the other side of the globe, producing an elliptical trajectory (Figure 2.1). Since this is a closed trajectory, the cannonball will come back to haunt the cannon crew, about 23¤4 hours after the projectile is fired, in this case. Note that the ball always returns to the low point on the orbit, the summit cannon, which is referred to as the orbit perigee. The high point, on the other side of Earth from the mountain, is called the orbit apogee. These are rather strange terms, but as the topic of orbit dynamics has been with us for so many years, a lot of wonderful terminology has come to us from history, as we will see later. Getting back to our cannon, further ramping up the barrel speed will result in higher and higher apogees, giving more and more elongated ellipses. Eventually, the apogee height will effectively reach infinity, an extremely long way away, and then the trajectory becomes an open parabola (Figure 2.1). If you ask the cannon crew to check the barrel speed, the crew members will tell you that the parabolic trajectory occurred at around 11 km/sec (6.84 miles/sec). If you also recall the discussion about the parabola in Chapter 1, it is the trajectory that results in escape from Earth's gravity with the minimum energy given to the cannonball. The ball flashes out of the cannon at huge speed, but this energy is consumed by the gravity field as it climbs away from Earth, and when it reaches infinity it effectively has no energy left to go anywhere, that is, it has zero speed. Any further increase in the barrel speed of the cannon will result in the ball's trajectory being a hyperbola (Figure 2.1). If you recall, this gives the ball sufficient energy to escape Earth's gravity, with some left over to give it a constant speed once it has reached a great distance from Earth. While Newton's cannon is helpful in revealing the nature of orbital motion, as you have probably guessed it does not have much to do with the realities of launching current spacecraft into orbit. This is done using launch vehicles, and we shall discuss in Chapter 5 how these are related to Newton's cannon.


How Spacecraft Fly

Weightlessness Now that we have a good feel for the nature of orbital motionÐessentially a spacecraft is in a state of free-fall under gravityÐwe can also achieve a similarly good understanding of the phenomenon of weightlessness. Weightlessness is something we see routinely on news coverage of manned space missions. (In this book I use the phrase manned space missions to mean flights involving peopleÐboth men and women. I know that the phrase may not be quite politically correct, but I dislike the other possibilities, such as ``crewed'' missions or ``peopled'' missions.) We have become familiar with crew members floating about their space ships, performing tricks such as swallowing floating globules of water, which would of course be impossible back on Earth. Despite this familiarity, however, there are again misconceptions about the nature of weightlessness, but it can be easily understood in terms of objectsÐspaceships, astronauts, and globules of waterÐfree-falling together in a gravity field. The key to understanding is an appreciation that all objects, independent of size and mass, fall with the same acceleration in a gravity field. The first statement of this principle is attributed to Galileo Galilei, who was born near the city of Pisa in 1564. To prove it, he is said to have dropped a cannonball and a wooden ball of the same size from the top of the famous leaning tower to demonstrate that the two balls would impact the ground at the same time, despite their different weights. Unfortunately, it is agreed by historians that this rather splendid story is of doubtful authenticity. A much better demonstration was performed on the moon's surface in July 1971, by Apollo 15 astronaut Dave Scott, who dropped a feather and a hammer together to see which of them would reach the lunar dust first. Since all three astronauts on this mission were serving members of the United States Air Force, the landing module was named Falcon, after the mascot of the U.S. Air Force Academy. The feather had to be that of a falcon, a detail that is of course entirely immaterial! You can perform this experiment nowÐif you happen to have a feather in one pocket and hammer in the otherÐbut I think you can guess the outcome. Clearly the feather, being much lighter than the hammer, will hit the ground some time after the hammer in apparent contradiction of Galileo's assertion that all things fall with the same acceleration. However, the experimental method in this case is flawed; there is the unfortunate presence of air in the roomÐfortunate for you, but not for the experiment! In the lunar surface experiment there is no air to influence the motion of the feather, and the feather and the hammer hit the dust at the same moment, giving a convincing demonstration that objects do fall at the same rate in a gravity field.

Basic Orbits


We can gain an understanding of weightlessness in orbit in terms of the spacecraft, the astronaut, and all other free objects inside the vehicle all falling together with the same acceleration in Earth's gravity field. To consolidate this idea, we can attempt to do an experiment on the ground to reproduce the effects of weightlessness by replacing our spaceship with an elevator in a very tall building. Strangely, the elevator is equipped with a weighing machine, as shown in Figure 2.2a. When we enter the elevator, while it is stationary, we can climb on the weighing machine, and we know that it will register our normal weight. We also have sufficient experience of riding elevators to know that, if we were to press a button to go up, we will feel heavier while the lift cable is accelerating the elevator upwardÐthe weighing machine will register this increase in weight (Fig. 2.2b). However, the part of the experiment to simulate weightlessness (Fig. 2.2c) is not to be recommended, as it involves cutting the elevator cable while disabling the elevator breaking system! In this case, the elevator and all objects within it will free-fall under gravity with the same acceleration, giving the same effects of weightlessness as seen on a spacecraft but for a rather shorter period of time! Interestingly, a number of research laboratories around the world offer such a facility commercially (called a drop tower), in which hardware experimentsÐbut not people!Ðare dropped to produce brief periods of weightlessness. Note that, in this discussion, it is important to make a clear

Figure 2.2: (a) Elevator stationary. (b) Acceleration of elevator upward causes increase in weight. (c) Elevator in free-fall produces weightlessness.


How Spacecraft Fly

distinction between weight and mass. Our unfortunate elevator rider in Figure 2.2 may have a mass of, say, 80 kg (175 lb), which remains constant throughout his scary adventure, but as we have noted his weight varies considerably depending on the state of motion of the elevator. Mass, according to Isaac Newton, is a fixed attribute of an object that characterizes its inertia; massive objects like pianos require a significant push to get them moving, whereas smaller objects require much less effort. This difference between mass and weight also had a surprising consequence for the Apollo moon-walking astronauts, who found they fell over rather more often than they were anticipating. A typical astronaut's mass, including space suit and backpack, was on the order of 130 kg (285 lb), but of course their weight in the lunar surface gravity was around one sixth of their Earth weight. This difference meant that the friction between their boots and the moon's surface was similarly reduced to one sixth of that on Earth. As they moved around on the moon's surface, sometimes quite rapidly, they had less contact friction with which to manage their significant massÐwith some interesting results!

Spacecraft Mission Analysis After the historical perspective of Chapter 1, and the earlier sections of this chapter, we now move on to begin to tell the story of modern spacecraft design. In the remainder of this chapter and the subsequent two chapters, we continue the theme of orbits, but in the context of spacecraft in orbit around Earth, or around another planet, or indeed around the Sun. Spacecraft mission analysis is a rather fancy term that spacecraft engineers use to describe the design of the orbital aspects of a spacecraft mission. On any spacecraft project there will be a team of people tasked with this job, which involves things like selecting the rocket that will launch the spacecraft, selecting the best orbit for the spacecraft to achieve the objectives of its mission, and determining how the spacecraft will be transferred from launch pad to final orbital destination.

Orbit Classification To discuss the types of closed Earth orbits that are commonly used by spacecraft operators, we need to consider the characteristics of typical orbits that uniquely distinguish one orbit from another. Principally, these distinguishing features are shape, size, and inclination.

Basic Orbits


Figure 2.3: Shape is a principal distinguishing characteristic of orbits. The degree of elongation of an orbit is defined by its eccentricity.

For closed orbits, the relevant shapes are circles and ellipses. Of course, some ellipses are more elongated than others, as shown in Figure 2.3, and this degree of elongation is referred to as eccentricity, with high eccentricity orbits being more elongated. Similarly, size is an easy idea, being defined by the orbit height. More precisely, a circular orbit will be defined by its radius, measured from Earth's center, or by its altitude above Earth's surface, as shown in Figure 2.4a. For elliptical orbits, the overall size of the orbit can be defined in terms of the distance between perigee and apogee (Fig. 2.4b). The perigee and apogee points may also be pinned down by their respective distances from Earth's center or surface. The third principal characteristic, orbital inclination, essentially defines the orientation of the orbit plane with respect to Earth's equator, as illustrated in Figure 2.5. The orbital inclination is defined as the angle between the orbit plane and the equatorial plane, measured at the ascending node of the orbit. Again in terms of the jargon, a node is simply a

Figure 2.4: The size of an orbit is a principal characteristic, and this is defined by the orbit's altitude above Earth's surface, or its distance from Earth's center.


How Spacecraft Fly

Figure 2.5: The angle between the orbit plane and the equatorial plane is called the orbital inclination. This is the third principal distinguishing characteristic of an orbit.

point on the orbit where the spacecraft crosses the equator, and an ascending node is one where the spacecraft is traveling from south to north. Looking at Figure 2.6a, we can see that an orbital inclination of 0 degrees gives an equatorial orbit, that is, one that overflies the equatorial region only. Conversely, an orbital inclination of 90 degrees gives an orbit plane perpendicular to the equatorial plane, as shown in Figure 2.6b. This type of orbit is referred to as a polar orbit. Of course, the orbital inclination may take any value between 0 and 180 degrees; a value of about 45 degrees is illustrated in Figure 2.6c. Another property of the orbit that is of interest, implied in Figure 2.4, is the orbital speed with which spacecraft move along their orbital path. This is not a principal characteristic, but an attribute that arises as a result of the

Figure 2.6: Orbits of differing orbital inclinations. (a) An equatorial orbit. (b) A polar orbit. (c) An orbit with an inclination of about 45 degrees.

Basic Orbits


orbit shape and size. The mathematics tells us that in a circular orbit, the spacecraft's speed is dependent on the mass of the central body and the orbit height. Given that we are considering Earth orbits, the mass of the central body, Earth, is of course constant, so the spacecraft's speed then becomes dependent only on the orbit height. A spacecraft in a circular orbit at particular altitude will move at a precisely defined speed. For example, in a 200-km (124-mile) altitude circular orbit, the spacecraft moves at 7.78 km/ sec (4.84 miles/sec), as we have already seen in our discussion earlier of Newton's cannon. This is a low Earth orbit (LEO). The rule is that as the circular orbit height increases, the orbit speed decreases; for example, a spacecraft in a 10,000-km (6200-mile) altitude circular orbit will travel at around 5 km/sec (3 miles/sec). In an elliptical orbit, the spacecraft speed along its trajectory is slightly more difficult to quantify, as the mathematics are a little more involved. But it can be understood easily in terms of the sharing of the spacecraft's energy between height and speed. As the spacecraft's altitude increases, its energy is sapped by its climb out of the gravity field and it slows down. At the apogee point of an elliptic orbit, the spacecraft speed will be lower than its speed at perigee. We have seen this already, expressed in a rather geometrical (17th century) way by Kepler's second law of planetary motion (see Chapter 1). A good parallel to help remember the variation in speed in elliptical orbits is bike riding on hilly terrain; your speed in the valleys is much higher than when climbing to the high points, for the same reasons of converting height into speed, and vice versa, as you ride.

Popular Operational Orbits Now that we have a grasp of the three principal distinguishing characteristics of orbitsÐshape, size and orbital inclinationÐwe can begin to look at the Earth orbit types that are most commonly used by spacecraft operators. Obviously, if we allow all possible variations in these three characteristics, then there is an infinite number of resulting Earth orbits to choose from! The popular orbits that we are about to introduce, therefore, are a small subset of this vast number of possibilities, and these are widely used simply because they have useful properties that enhance the performance of scientific and applications spacecraft. In writing this chapter, I found it difficult to decide what to include and what to leave out. No doubt other experts would say, ``Well, what about such and such an orbit, which is often used for this or that?'' I guess the reader has to accept that sometimes things are simplified and generalized a little to aid clarity.


How Spacecraft Fly

Bearing in mind these comments, five types of popular operational orbit are identified, and these are summarized in the following box for quick reference. Some popular operational Earth orbits 1.

2. 3. 4.


Low inclination LEO A circular Low Earth Orbit with an orbit plane varying from equatorial up to about 508 inclination. Near-polar LEO A circular Low Earth Orbit with an orbit plane inclined near 908. HEO A Highly Eccentric Orbit. GEO A circular, equatorial orbit at a height where the orbit period is 1 Earth day. This is referred to as a Geostationary Earth Orbit. Satellite constellation orbits. A network of usually identical circular, inclined orbits, often accommodating a large number of satellites.

Low-Inclination LEO

This is a circular low Earth orbit, with an orbit plane that is near-equatorial (Fig. 2.7). However, the simplicity of this statement is deceptive, and what we mean by ``low'' and ``near-equatorial'' requires qualification.

Figure 2.7: Low-inclination low Earth orbit (LEO). Large vehicles, such as space shuttles and space stations, are often accommodated in this type of orbit. (Image courtesy of the National Aeronautics and Space Administration [NASA].)

Basic Orbits


Surprisingly there is much debate among experts about the meaning of the word low, but my working definition is altitudes below about 2000 km (1240 miles). The phrase near-equatorial similarly gets a wide interpretation, meaning orbit planes ranging up to around 50 degrees in orbital inclination. The kinds of spacecraft found in this type of orbit are often large, that is, massive, manned vehicles such as shuttles and space stations, or large unmanned spacecraft. An example of this class of unmanned vehicle is the well known Hubble Space Telescope, which is about the same size and mass as a double-decker busÐaround 11,000 kg (24,000 lb). The mass of space vehicles and the type of orbit in which they are accommodated are related. As we will explain in more detail in Chapter 5, it is much easier to launch large spacecraft into low, near-equatorial orbits. Also, given that the plane in which the planets orbit the Sun is close to Earth's equatorial plane, spacecraft destined to probe distant planets are often launched into a near-equatorial LEO. This is then used as a kind of parking orbit, to check out the spacecraft's onboard systems, before a rocket is fired to take the probe to its ultimate destination.

Near-Polar LEO

This orbit is used mostly by operators of Earth observation and surveillance spacecraft (Fig. 2.8). It is a popular operational orbit, particularly at altitudes in the region of 700 to 1000 km (435 to 620 miles), and this is mainly driven by a need to get a global perspective on environmental issues such as climate change. Consequently, many national and international space agencies have launched (and are planning to launch) an armada of spacecraft equipped with powerful instrumentation directed downward to the Earth's surface. Earth observation also has a military dimension, and many military agencies are launching surveillance satellites to gain the new military ``high ground.'' It is perhaps not well known that the biggest spender on space in the world is the U.S. Air Force, and details of most of their spacecraft and activities are classified. However, to get a feel for the capabilities of their optical surveillance satellites, you have to imagine a spacecraft with similar imaging power to the Hubble Space Telescope, but directed down instead of up! It is easy to see why near-polar LEOs are good for Earth observation. Figure 2.8 demonstrates that there is potential for our spacecraft to see most of the planet's surface if we wait long enough; this is called global coverage. As our spacecraft orbits once every 100 minutes (typically), and Earth rotates once every 24 hours beneath the orbit plane, the spacecraft operators can image most targets of interest worldwide within a day or two. The targets of interest can vary substantially in character, from the health of a crop of maize to tank movements on a battlefield.


How Spacecraft Fly

Figure 2.8: Near-polar LEO. This is commonly used by Earth-observation satellites, like the Landsat spacecraft shown. (Image courtesy of NASA.)

If we compare the near-polar LEO with the low inclination LEO, we can get a good idea of why the near-polar orbit is so well suited to Earth observation missions. It is obvious from Figure 2.7 that if we launched an Earth observation satellite into a low-inclination orbit, we would get a good look at the near-equatorial regions of Earth, but not much else.


The geometry of a typical highly eccentric orbit is shown in Figure 2.9, which is inherently useful for a variety of missions.

Basic Orbits


Figure 2.9: The highly eccentric orbit (HEO). One type of mission that it accommodates is astronomical observatories, such as the XMM Newton X-Ray Telescope. (Image courtesy of the European Space Agency [ESA].)

The HEO has accommodated many scientific spacecraft, for example, the European Space Agency Cluster mission, dedicated to exploring Earth's magnetic field, and the energetic atomic particles that are trapped within it.


How Spacecraft Fly

The source of these particles is the solar wind, a stream of high-speed ionsÐ atoms stripped of their electronsÐemanating from the Sun. When these encounter the magnetic field of Earth, some of them are trapped in nearEarth space to form doughnut-shaped regions filled with energetic particles (see Chapter 6). These regions were named the Van Allen radiation belts in 1958 after their discoverer, and the particle radiation they contain is hazardous to both man and spacecraft systems. Understanding this hazard has been an important endeavor, and the HEO provides the best means of doing this, as a spacecraft in this orbit is able to sample the magnetic field and particles over a wide range of altitudes on each orbit. The HEO is also a popular orbit for space observatories. An observatory at the apogee of a HEO has good sky viewing efficiency, as the distant Earth obscures only a small part of the sky. Also the relatively slow speed at apogee means the spacecraft spends most of its time there, providing good opportunities for extended periods of communication with the ground. This allows ground operators to command the telescope and receive its data as if it were effectively on the ground in a dome next to the control room. This way of operating is referred to as observatory mode operation and is an important attribute for space telescopes. Also the high apogee of the HEO means that the observatory spends most of its time above the Van Allen radiation belts, which is beneficial for some instruments that cannot operate in a high radiation environment. The HEO has also been used extensively as a communications orbit, mainly by the former Soviet Union and by Russia today. A HEO inclined at 63 degrees to the equator, with an orbit period of 12 hours, is called a Molniya (Russian for ``lightning'') orbit after a series of communications satellites accommodated in this orbit. The Soviet Union began to use this orbit in the 1960s for communications between ground sites at high northern latitudes, by positioning the apogee of the orbit above the Northern Hemisphere. The low speed of the spacecraft in the apogee region means that it spends the majority of its orbit period high in the sky above these northern regions, giving an opportunity for extended, uninterrupted periods of communication with terrestrial users. Between 1964 and 1998, around 170 spacecraft were launched into Molniya orbits to provide telephone communication and satellite TV to high-latitude regions bordering the Arctic Ocean.

Basic Orbits


Figure 2.10: The geostationary Earth orbit, shown to scale. There are many communication satellites in this orbit, such as the Intelsat spacecraft illustrated. (Image courtesy of EADS Astrium.)


The geostationary Earth orbit is a widely used operational orbit, mostly for communications, but also for scientific and Earth observation satellites (Fig. 2.10). An example of a GEO orbit Earth observation satellite is Meteosat, which provides those impressive weather pictures we see each evening on the television weather forecast. The invention, if such it can be called, of the GEO is attributed to the science-fiction author Arthur C. Clarke in 1945. Unfortunately, he failed to patent the idea; if he had done so, he would probably be very rich today! The reason for the popularity of the GEO as an operational orbit is its unique characteristic that satellites in this orbit appear to be stationary when seen from Earth's surfaceÐhence the name. To achieve this, the orbit needs to be circular and equatorial, but in addition the orbit height has to be such that the spacecraft orbits Earth in the same time as it takes for Earth to rotate once on its axis. There is often confusion about the meaning of the term geosynchronous orbit (GSO) and how it relates to the GEO. GSO is the name used for any


How Spacecraft Fly

orbit that has an orbital period equal to one Earth rotation, so the GEO is a special case of the GSO. There are obviously a whole bunch of GSOs with a 1day period, but having an elliptical shape, or a plane inclined to the equator, or both. The important distinction is that a spacecraft in one of these GSOs does not appear stationary relative to a ground-based observer. Usually the orbit period of a GEO is said to be 24 hours, but it is actually a little shorter than thatÐ23 hours and 56 minutes. The day on which we base our calendar is the familiar 24 hours, which is called the solar day, and this is the time it takes for Earth to rotate once with respect to the Sun. If the Sun is precisely due south (or due north if we live in the Southern Hemisphere) and we measure the time it takes for it to return to the same position in the sky the next day, we will find it to be the familiar 24 hours. The period of the GEO satellite, 23 hours 56 minutes, is called the sidereal day, which is the time it takes for Earth to rotate once with respect to the distant stars. The reason for the difference is Earth's orbital motion around the Sun; because of this, the Sun appears to move relative to the stars. As Earth rotates, it takes 23 hours and 56 minutes to do one revolution with respect to the stars, and then it has to rotate for an extra 4 minutes to catch up with the Sun, as the Sun's position has changed from the day before. Getting back to our GEO spacecraft, we can calculate the orbit height corresponding to this orbit period using Kepler's third law of planetary motion (see Chapter 1). If we do this, we get a precise altitude for our GEO of 35,786 km (22,237 miles). If we have a circular, equatorial orbit at this height, a satellite initially positioned above a particular geographical feature on the equator will remain above that feature as it orbits; it appears to stand still in the sky from the point of view of someone on the ground. This property is the key to its popularity. It makes communication with the spacecraft easier, as you don't need to track the satellite with your dish antennaÐyou just point it in a fixed direction. And of course it also means that the communications link with the spacecraft is uninterrupted. This is a familiar idea, as evidenced by the large number of small satellite TV receiving dishes we see bolted to the exterior walls of houses, staring fixedly at a particular point in the sky where the service provider's invisible GEO satellite resides. The GEO orbit is most commonly used by communication spacecraft, and there are literally hundreds of active communication satellites (comsats) on the GEO arc. People routinely use this technology day to day, without really noticing, which is of course the way it should be. If I pick up the phone to say, ``Hi, this is Graham'' to a friend on another continent, then my electronic voice will transit over land lines or microwave links to the nearest satellite ground station, where it will be transmitted into the sky to a GEO

Basic Orbits


comsat by a large fixed dish antenna. This signal will be received and amplified by the spacecraft, and then transmitted down to another ground station in the region of my friend's home, ultimately arriving at his telephone handset. When he responds by saying, ``Oh hello! How are you?,'' the whole process begins again in the reverse directionÐamazing technology that is transparent to the user! The nature of the GEO arc is that it is literally a one-dimensional line in space, and as such it is a limited natural resource that needs to be protected and managed for the future, like any other. Unfortunately, as well as all the active comsats on GEO, there are many defunct spacecraft that are essentially debris polluting the orbit. Because of the pressure of use on the GEO arc, spacecraft operators are now expected to boost their comsats to a higher graveyard orbitÐ200 or 300 km above GEOÐwhen they reach the end of their operational life.

Satellite Constellation Orbits

The orbits associated with a satellite constellation are usually a network of identical inclined circular orbits, often accommodating a large number of satellites. A typical constellation geometry is illustrated in Figure 2.11, where the black dots represent the orbiting satellites comprising the constellation. Constellations have been most commonly used over several decades for satellite navigation (satnav), which uses satellites to determine your position on the ground (or on the ocean, in the air, or wherever you happen to be). More recently, constellations have been used for satellite communications, and there is currently an interest in using them for Earth observation as well. Perhaps the best known example of a constellation is the global positioning system (GPS) navigation system. Navstar GPS satellites (see Chapter 1) are operated by the U.S. Department of Defense, mainly for use by the U.S. military. However, satnav in automobiles is becoming commonplace, as well as in leisure activities such as hiking and sailing, giving the user's position with an accuracy on the order of 10 m (32 feet). To triangulate a user's position on the ground, the receiver needs to access signals from at least four GPS satellites simultaneously. To make this work, the constellation must be designed so that the user can see at least four GPS satellites from any location on Earth's surface at any time. This ground coverage requirement leads to the design of the geometry of the satellite constellation. In this case, the required ground coverage is achieved by the operation of 24 satellites in the constellation. The resulting geometry of the constellation consists of six circular orbit planes at 20,200 km (12,500 miles) altitude, spread out around the equator. Each orbit plane is inclined at 55 degrees to the equator and accommodates four satellites. Figure 2.12a shows


How Spacecraft Fly

Figure 2.11: An illustration of a typical LEO constellation geometry for a communications system. The black circles represent the orbiting satellites that comprise the system.

How Spacecraft Fly Graham Swinerd How Spacecraft Fly Spaceflight Without Formulae CoperniCus Books An Imprint of Sp...

Author: Graham Swinerd

212 downloads 980 Views 45MB Size Report

This content was uploaded by our users and we assume good faith they have the permission to share this book. If you own the copyright to this book and it is wrongfully on our website, we offer a simple DMCA procedure to remove your content from our site. Start by pressing the button below!

Report copyright / DMCA form

how to craft spacefly egg collection

WATCH THE VIDEO ON THEME: Egg collection in IVF flushing follicels with a single lumen needle.

Results 1 - 24 of 24 Dragon craft z.

how to craft spacefly egg collection
Written by Mekora
  • Yoktilar

    YoktilarMarch 02, 2019 9:06 AM

    I can suggest to come on a site on which there are many articles on this question.

  • Tabei

    TabeiMarch 02, 2019 12:15 PM

    I consider, that you are mistaken. I can prove it. Write to me in PM.

  • Jugore

    JugoreMarch 01, 2019 8:35 AM

    Thanks for the help in this question, can, I too can help you something?

Write a comment