Category Space Ship One

SpaceShipOne, with its landing gear retracted, was rolled on a dolly underneath White Knight and then raised using a hand crank. The top of SpaceShipOne attached to a two-point pylon that was mounted on the belly of White Knight. Two hooks inside the pylon, fore and aft, clamped onto SpaceShipOne, securing the vehicles together, as shown in figure 3.3. Heating ducts from White Knight to SpaceShipOne also ran through the pylon. The wings of SpaceShipOne were further secured by braces running down from White Knight. The clearance between the two was only a meager 1 foot.

The optimum time to launch from Mojave Airport was at day­break. Figure 3.4 shows a predawn preflight briefing, which reviewed the mission readiness and addressed any last-minute concerns. After White Knight, carrying SpaceShipOne, rolled out of the Scaled

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Fig. 3.3. SpaceShipOne attached to White Knight at several points. A pylon underneath White Knight housed two hooks that fit into two rings on top of SpaceShipOne. A brace between each set of wings also helped to stabilize SpaceShipOne and keep it from swaying back and forth. Mojave Aerospace Ventures LLC, photograph by David M. Moore

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Fig. 3.4. Early in the morning before each test flight, a preflight briefing was held so that the test pilots, ground crew, and Mission Control could review the details of the flight plan and receive updates on the status of the vehicles and the weather conditions. Mojave Aerospace Ventures LLC, photograph by Scaled Composites

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Fig. 3.5. White Knight and SpaceShipOne taxi to Mojave Airport’s Runway 30. Located less than eighty miles northeast of Los Angeles, Mojave Airport became the first inland spaceport and the first public spaceport licensed by the FAA. Mojave Aerospace Ventures LLC, photograph by Scaled Composites

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Fig. 3.6. Inside Mission Control, the flight director, Doug Shane (seated

front row center), was the point person on the ground who communicated directly to the pilots aboard SpaceShipOne and White Knight during all phases of the mission. The Mission Control staff monitored all aspects of SpaceShipOne based on the instrument and video data transmitted by the craft. Mojave Aerospace Ventures LLC, photograph by Scaled Composites

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Composites hangar and final preparations were completed, the two vehicles taxied out to the runway. Figure 3.5 shows White Knight and SpaceShipOne getting ready for takeoff. Once in the air, White Knight headed 40 miles (64 kilometers) to a release box, an area that had been designated by the FAA.

Early in the program, the target for the separation altitude was

50.0 feet (15,240 meters). However, both the characteristics of the air, more specifically the density, and the performance of White Knight, or lack thereof, favored a separation altitude closer to

47.0 feet (14,330 meters). For this first stage of the ascent, White Knight spiraled up at a rate of about 700 feet per minute (210 meters per minute). And by the time the vehicles reached 45,000 feet (13,720 meters), the vehicles were above about 85 percent of the atmosphere.

“We fly up there on White Knight, and that is a really long period of time. It is close to an hour to get up there,” Melvill said.

“I really hated the ride up there,” he continued. “No one wants to talk to you. They think you need to sit there and concentrate on what you are about to do. I really would have liked someone to distract me and have a conversation about something else, because an hour is a long time to sit there and worry about what’s going to happen.

“You start getting close to the drop zone and close to the altitude. Then you go through a pretty extensive checklist setting the airplane up. You trim it 10 degrees nose up, so that when it drops off, it holds its nose up.”

Watching for the slightest abnormality, Mission Control carefully monitored the flight data and video transmitted by SpaceShipOne during the entire flight, as figure 3.6 shows.

It was possible to rotate the entire horizontal stabilizer on each of the tail booms. Adjusting it with 10 degrees nose-up trim would help ensure that SpaceShipOne didn’t go into a dive once it detached from White Knight. This setting was also necessary to help force the nose up once the rocket engine fired, enabling SpaceShipOne to move from horizontal flight to nearly vertical flight.

Figure 3.7 shows a close-up of SpaceShipOne during the captive-carry.

The procedure for the airborne launch of the rocket-powered second stage from the carrier aircraft was pretty simple. Even before the 1920s, flying vehicles had been dropped by larger flying vehicles. And NASA extensively used motherships for dropping X-planes and even for flight testing the Space Shuttle (refer to figure 3.8 and figure 3.9, respectively).

White Knight had to remain steady with its wings level. The pilot in SpaceShipOne began the sequence by arming part of his release system. In the cockpit of White Knight, a yellow light then came on. White Knight would arm next, giving another yellow light. At that point, the release handle inside White Knight became “hot.” A crew member in the backseat pulled it to retract the hooks. White Knight shook with a big bang as the spring-loaded hooks came to a sudden stop. SpaceShipOne dropped away as White Knight surged upward.

“There is an instant feel of you climbing,” said Pete Siebold about flying White Knight during this separation. “You lost almost half your weight. You were at 1 g and it jumped up to 1.6 g’s the second you pulled the release handle.”

Siebold flew SpaceShipOne three times, but all the test pilots pulled double duty when it came to flying. During flight tests with SpaceShipOne, one of the other SpaceShipOne pilots always flew White Knight.

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Fig. 3.8. Carried to a height of

45,0 feet (13,720 meters) by a NASA B-52, the North American X-15 dropped from the wing at a speed of 500 miles per hour (800 kilometers per hour). The X-15 would typically carry out one of two missions: high-speed hypersonic (faster than Mach 5) test flights or high-altitude test flights. NASA-Dryden Flight Research Center

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Fig. 3.9. The Space Shuttle Enterprise launches from the top of a NASA 747 Shuttle Carrier Aircraft (SCA). During the test flight, Enterprise glided back down to Dryden Flight Research Center, so aerodynamic and control characteristics could be evaluated prior to an actual spaceflight. NASA-Dryden Flight Research Center

For safe separation from White Knight, as shown in figure 3.10, the pilot in SpaceShipOne pushed forward on the control stick. This briefly counteracted the trim setting on the horizontal stabilizer. So, instead of wanting to pitch up, SpaceShipOne dipped down to avoid re-contacting White Knight.

Gliding for about 10 seconds, SpaceShipOne grew quiet, since it was now out of earshot of White Knight’s engines. The pilot made some quick final checks with Mission Control.

“You have to get the motor started as soon as you possibly can because you are just teetering on the edge of a stall,” Melvill added. “You’ve got all
that rubber fuel at the back of the airplane.” The center of gravity for SpaceShipOne was very far back. If its nose pointed up too high, without the rocket engine going, a stall would develop that would cause the space­ship to lose aerodynamic control. A pilot could recover from this, but SpaceShipOne would have lost a good deal of altitude in the process.

hen SpaceShipOne touched down on Mojave’s Runway 30 after its third flight into space, it not only won the Ansari X Prize, but it also, in a way, completed a journey that had started on two separate paths that intertwined along the way and then finally merged together in 2004. SpaceShipOne was a small, lightweight rocketship somewhat resembling NASA’s early X-planes but with elements of Burt Rutan’s distinct flair for the unique and unconventional. Figure 1.1 shows Burt Rutan with Doug Shane, the test flight director, and the three SpaceShipOne test pilots, Pete Siebold, Brian Binnie, and Mike Melvill.

On that day test pilot Brian Binnie did more than capture the Ansari X Prize. He captured people’s imagination and reignited the space-crazy in them. Back in 1927, Charles Lindbergh, who just barely cleared telephone lines after takeoff in pursuit of the Orteig Prize, crossed the Atlantic Ocean nonstop from New York to Paris and sparked a boom in aviation like none other. These two turn­ing points forever changed the way people looked up into the sky and saw them­selves flying free as the birds or high as the stars.

Without people there would be no flying machines. It is not the mechanisms of engine, fuselage, wing, and empennage that provide transport into the air and through the clouds: it is the people whose ideas, visions, and daydreams have taken flight and soared. Without the human mind, the greatest height reached would only be as high as the highest surface that could be climbed.

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Fig. 1.1. Burt Rutan (top left), the SpaceShipOne and White Knight designer, and Doug Shane (top right), the test flight director, stand behind their test pilots, Pete Siebold, Brian Binnie, and Mike Melvill (left to right). Mojave Aerospace Ventures LLC, photo­graph by Scaled Composites

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It is no coincidence that the breakthroughs in aviation have come from ingeniousness and inventiveness as early as Leonardo da Vinci’s drawings of flying corkscrews and birdlike flight suits, or even earlier when the ancient Greeks pondered the air around them. As ideas like these were being conceptualized, more often than not, peers would view such thinking as folly, insanity, or even sacrilege.

Thankfully, there are a few whose hides are thicker than most, whose resilience is more enduring than most, and whose passion burns brighter than most. And more importantly, there are some whose persistence in moving forward, even if it takes stepping back­ward at times, is unwavering. It is not enough to be a great thinker. The genius lies in the execution. As inventor Thomas Edison is famous for saying, “Genius is one percent inspiration, ninety-nine percent perspiration.”

But these factors are no longer enough in this day and age. In centuries past, it may have been sufficient for just one person to cultivate a dream, from beginning to end, into fruition. But in today’s ever changing, ever more complicated society, often a wheel with only one cog will not provide the grip needed to take hold of an idea and spin it into something magical. It is only when the sprocket has gathered enough teeth that it can truly turn and move forward in a synchronicity of movement.

Burt Rutan

In 1965, Elbert L. “Burt” Rutan found himself in the backseat of an F-4 Phantom trying to figure out how to regain control as the fighter jet whirled around in circles in an unrecoverable flat spin. At the time, the Phantom was one of the U. S. Air Force’s frontline fighters. Under the right set of conditions, though, pilots could enter a flat spin where the only way out required the use of their ejection seats. A total of sixty-one aircraft had been lost because of this, and Rutan’s job was to determine a way to recover from this disastrous condition.

Fresh out of college, it was certainly a dream job for someone who had craved a challenge. Born in Portland, Oregon, in 1943 and raised in Dinuba, California, southeast of Fresno, he had been flying model airplanes that he designed and built since he was a young boy.

“None of those things were kits,” Rutan said. “They were original designs.” He entered model-airplane competitions during high school while also learning to fly. His models took him to the nationals, and he brought home trophies.

“I was of course fascinated by space,” Rutan recalled. “I listened to the Alan Shepard flight on the radio as I was driving to my college to interview.”

Rutan attended California Polytechnic University, where he would receive his bachelor of science in aeronautical engineering. In 1964, he was one a very few students, the only one from his college, selected to attend the CalTech Space Technology Summer Institute. During this time the United States continued to lag behind the Soviet Union in the space race. Yuri Gagarin, aboard Vostok 1, had become the first man in space three years earlier, and it would be yet another five years until Neil Armstrong and Buzz Aldrin would set foot on the Moon.

The U. S. space program was hungry for engineers during this electrified time. It seemed natural that someone like Rutan would have his sights set on Apollo manned Moon missions.

Rutan remembers his boyhood imagination being stirred by watching television programs where Wernher von Braun, who headed Germany’s V-2 program but was now leading NASA’s Saturn V rocket development, talked about the exploration of the Moon and Mars with Walt Disney.

“Von Braun was a big hero of mine because of the Disneyland television show in 1955,” Rutan said. “Those programs were enormously compelling to me as a twelve-year-old because we didn’t know much about Mars in ’55. I have a college astronomy textbook that I had gotten a long time ago. It was written in ’53. It is interesting to read because they are debating what kind of life is likely to be on Mars and would there be a chance that it would be intelligent life. So, imagine yourself back in a time period when you believed there was vegetation there because you saw the colors change in the telescopes.”

Rutan had a tough decision to make when it came time to leave college. Although the space program barreled forward, and opportunities
certainly waited for him, he was very skeptical about how and where he would fit in. “I felt I was so far behind on being able to come in and take a new idea and actually get it out there flying if I focused on spaceflight or manned spaceflight.”

He didn’t want to work on the space widget of the what-cha-ma-call – it subsystem. While this obscure part was indeed a piece of the puzzle that would have been necessary for launch, Rutan desired to really make a big impact and influence the big picture. Working for an airliner or fighter manufacturer didn’t interest him, for the same reason. “I’d be working on a bulkhead or a door.”

So, he turned in another direction. “I thought I could make a big dif­ference with general aviation, which I thought was archaic and frozen.” He felt that he’d have the opportunity to let his creativity fly, even if it wouldn’t be quite as high as if he worked for the U. S. space program. But Rutan’s competitiveness helped sway him in yet another direction.

“I couldn’t bring myself to go work on Cessnas while everyone I went to school with was on the way to the Moon. So, I made a compromise. I went into air force flight testing.”

This was by far the best decision Rutan could have ever made. Working as a civilian at Edwards Air Force Base in Mojave and spending six to ten months on an aircraft before moving to the next one, he learned what risks to take and what decisions to make when testing out new aircraft. This education, he felt, was critical for a designer.

“I’m out there evaluating the performance, flying qualities, safety, etc., of the top-of-the-line, brand-new military airplanes. I got to fly in them, measure data, and report on their performance.”

In the Phantom on that day in 1965 when it went into a flat spin, once Rutan and the test pilot were sure that the flat spin was unre­coverable, they deployed a special recovery parachute that forced the large fighter jet out of the spin. “I’ve done the only flat spin in an F-4 that did not have an ejection.” But the very next flight, with a different test engineer in the backseat, the spin recovery chute failed, and both the pilot and test engineer ejected to safety. Rutan still keeps in his office a piece of the F-4’s canopy from the wreckage that actually has his name on it. Eventually a procedure would be devised using the Phantom’s existing landing drag chute, which greatly reduced the rate of unrecoverable flat spins.

Rutan left the air force in 1972. He explains, “Now I could really exercise with my own responsibility, my own authority, my own decision on risk taking with nobody to answer to in developing the VariViggen, the VariEze, the Defiant, the Solitaire, and all these homebuilts. That path could never have accelerated at that rate if I had gone into the space program.”

Clear of White Knight, the pilot armed the rocket engine, flicked the ignition switch, put his head back against the seat, and grabbed the control stick with both hands.

“When you light that rocket motor off, everything literally starts with a bang. There is so much energy associated with that rocket motor. It is like a tsunami sweeps through the cabin and literally takes you away,” said Brian Binnie, the pilot who flew the first and last powered flights of SpaceShipOne.

“You really have nothing in your background or DNA to tell you that what is happening to you is good. You have no basis. Three or four seconds will go by, and you go, ‘Ah, I’m not dead. Therefore, it must be going as they told me it was going to go.’”

The roar from the rocket engine was extremely loud. “The noise is certainly worse right at ignition when you have little forward speed,” explained Binnie. “But as soon as you are supersonic, you are going faster then any sound that the rocket motor makes. It doesn’t really penetrate the cabin a lot. What you hear in the cabin is all the gurgling off the main oxidizer tank that’s right on the other side of the bulkhead from which you’re located. So, you hear that. There is a certain amount of wind noise over the vehicle. A good helmet with reasonable ear protection let the radio come across just fine.”

The force pinning the pilot to his seat just added to the flood of sensations. “The acceleration is fierce. It’s abrupt. It’s sudden. It’s a big slap in the back and whoosh off you go. It is a very dynamic environment, and you are very much holding on for dear life,” Binnie said.

“As it develops, your body readily adjusts to the g’s that you are experi­encing. They are not that high during boost. They are between 3 or 4.” Having been a former navy fighter pilot, Binnie had some experience with some pretty fast starts. The initial kick from a catapult off the deck of an aircraft carrier had some similarity. After 2—2.5 seconds, the acceleration from the catapult was over, but after the same amount of time, SpaceShipOne would still be going and going.

“A catapult shot takes you from 0 to about 150 miles per hour [240 kilometers per hour] in 2 to 2.5 seconds. If you continue that accel­eration rate, which is kind of what the spaceship is doing, you would then go from 150 to 300 miles per hour [480 kilometers per hour] in another 2.5 seconds or the 5-second mark. And at the 8-second mark, you’d be doing not 300 miles per hour but 600 miles per hour [970 kilometers per hour]. And by the 10-second mark, you’d be supersonic.”

The pilot held the control stick with both hands because, as SpaceShipOne moved faster and faster, the forces from the outside air pushed harder and harder against the vehicle and its controls. The pilot had to make sure the nose was coming up right away. Otherwise there was a danger of overspeeding SpaceShipOne and breaking it apart. The “never-exceed” speed was around 260 knots equivalent airspeed (KEAS). A knot is a nautical mile per hour, which is a little faster than a mile per hour. Equivalent airspeed is a measure of how fast a vehicle feels it’s going in terms of the air pres­sure pushing against it. So, this value may seem very low, but SpaceShipOne started out already operating above 85 percent of the atmosphere. The air density was very low to begin with and didn’t exert as much air pressure as if the vehicle were flying at a lower altitude where the air density was higher.

Figure 3.11 shows SpaceShipOne during the initial pull up, also called “turning the corner” or the “gamma turn.” With the feather locked down tight, it was critical for the pilot to keep the wings level during this phase.

“Because our wings are level, that turn results in pointing nose up,” Pete Siebold said. “So, if any portion of the time you roll to a

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Fig. 3.11. Once the rocket engine ignited, the test pilot immediately had to begin to pull the nose of SpaceShipOne up in a maneuver called "turning the corner." By the time the turn upward was complete, SpaceShipOne was already traveling at supersonic speeds. Mojave Aerospace Ventures LLC, video capture provided courtesy of Discovery Channel and Vulcan Productions, Inc.

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non—wings level attitude, instead of going up, you are going to turn to a different heading and not go up. A significant amount of the energy is spent doing that initial turn.

“If there was any time spent non—wings level during this turn, you ran the risk of not making your ultimate goal of 100 kilometers [62.1 miles] at the end of the flight.”

A number of things caused the wing to wander back and forth. Asymmetries in the thrust from the rocket engine and asymmetries that resulted from supersonic shockwaves wanted to knock SpaceShipOne off course.

Melvill added, “And there are wind shears that exceed 100 miles per hour [160 kilometers per hour] going in different directions. So as you go up, it will blow you this way and then it blow you that way. You are not there for long, so you don’t get massive changes, but you are constantly correcting.”

By using an avionics system called the Tier One navigation unit (TONU), the pilot could ensure that SpaceShipOne was wings level and had the proper pitch rate, which was a measure of how fast the nose was rising. For the first 5 seconds, the pilot used the control stick and the rudder pedals to keep the wings level. “You can feel the forces start to build quite rapidly,” Binnie said. “And now your thinking is, ‘Okay, I’m going to keep fighting this thing physically until about 8 or 9 seconds, and then I’m going to transition over to controlling the vehicle with electric trims.’” To do this, the pilot took his left hand off the stick and reached for the rudder trim controller, a big black knob that looked liked a turtle shell.

Binnie explained, “As you are going through transonics, where the vehicle is shocking up asymmetrically, it is still rocking back and forth or more like whipping back and forth. Your job is to try to filter out the oscillatory motion and chase down with the turtle any longer-term disturbance that is driving the nose of the vehicle off trajectory.

“You have high-rate motions but you have a low-rate controller. So, things don’t happen as quickly as you’d like them to. You put in an

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Fig. 3.12. Traveling close to vertical, SpaceShipOne’s hybrid rocket engine burned 76-84 seconds during a spaceflight. At rocket engine shutdown, SpaceShipOne was a little more than half the way up to apogee. Mojave Aerospace Ventures LLC, photograph by Scaled Composites

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adjustment, and you’re going to have to be patient to sort of see it take effect. And that is not the easiest thing in the world to do because you just had your brains scrambled. And everything about you is on high alert, and now you have to be patient and wait for the thing to respond. If you don’t, it is easy to over-control it, and you can get yourself into even more trouble.”

As the pilot was finishing the initial pull up, SpaceShipOne passed the rough transonic transition from subsonic to supersonic.

“You settle in around the 10- to 15-second mark and look out the window. And appreciate that you are no longer horizontal. The nose will appear vertical, but it is not quite there yet,” Binnie said.

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Fig. 3.13. Photographed from inside the cockpit of SpaceShipOne by Brian Binnie near the apogee of 367,500 feet (112,000 meters), the Channel Islands and the Pacific Coast peek through the cloud cover as black sky shrouds Earth. Mojave Aerospace Ventures LLC, photograph by Scaled Composites

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Figure 3.12 shows SpaceShipOne and its contrail during the ascent to space.

As SpaceShipOne continued to ascend and slowly move its nose closer to vertical, the use of the control stick came back. The pilot could again use the mechanical controls to fly, even though it traveled much faster than Mach 1 and was still gaining speed. The air density was too low to create much opposing force but still high enough for aerodynamics to work.

At about the 1-minute mark, the rocket engine went through a liquid-to-gas transition. “This is kind of a wake-up call that you are getting near the end of the boost phase of flight,” Binnie said. “The vehicle shakes and shudders some more. And then the rocket motor valve that you are sitting not too far from has some unusual acoustics
associated with it. It sounds like riding along with a possessed cat. It kind of screeches and howls and complains.”

SpaceShipOne reached a maximum speed of Mach 3.09, or 2,186 miles per hour (3,518 kilometers per hour).This occurred just before burnout while it was still accelerating. But the atmosphere was very thin at this point, so the airspeed was only about 40 knots equivalent airspeed.

The highest altitude for rocket-engine shutdown occurred at

213,0 feet (64,920 meters). The burn lasted 84 seconds. Unlike shutdown inside the thick atmosphere, where thrust no longer kept the pilot pinned to the seat and the deceleration force flung him forward in his seat, shutdown at high altitudes was tame because of the thin atmosphere and because the rocket engine’s thrust had tapered off due to the longer burn duration. SpaceShipOne now coasted upward.

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Fig. 3.14. During the 3.5 minutes of weightlessness, the test pilots were able to take photographs from inside SpaceShipOne’s cockpit. In this photograph, the red-colored thermal protection on the leading edge of the right wing can be seen through one of the porthole windows. Mojave Aerospace Ventures LLC, photograph by Scaled Composites

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“Three wonderful things happen/’recalled Binnie. “The noise goes away. The shaking, the shuddering, the vibration go away, and you become instantly weightless. And the weightlessness is just a pro­foundly exciting and pleasurable experience.”

“Then of course there is that view. You’ve seen it on the cover of magazines and things like that. But when you see it for yourself, it is really breathtaking. The eye is so much more dynamic than a video or a camera. It is yours for the enjoyment.”

As SpaceShipOne rocketed upward, light scattered less and less in the dwindling atmosphere. “You can already see the blue skies turning a much darker, deeper shade of blue and as you continue to watch that, it will deepen and darken and kind of go purplish and then to black,” said Binnie.

Figure 3.13 shows the black sky surrounding Earth in a photo­graph taken by Brian Binnie aboard SpaceShipOne. So where are the stars in the black sky? Above the atmosphere there should be stars galore. Well, they are there. However, a camera cannot catch the stars. Earth is much too bright. To see the stars in a photograph, a much longer exposure time is needed, but then the features of Earth would be totally washed out. This phenomenon can also be observed in the famous “Earthrise” photograph taken by the crew of Apollo 8 as they circled the Moon, where Earth is seen rising above the sur­face of the Moon and no stars can be seen in the background.

Following a ballistic arc, the unpowered spacecraft continued to climb, coasting up while the atmosphere dwindled away. To win the Ansari X Prize, it was necessary to reach an altitude of 328,000 feet (100,000 meters). So, as SpaceShipOne raced toward this height, the pilot enjoyed the effects of zero-g. Without the atmosphere, the drag
caused by the air resistance was no longer a factor causing SpaceShipOne to decelerate. Gravity still had a hold on SpaceShipOne, however, and the spacecraft was not traveling at a high enough veloc­ity to escape the pull of Earth.

Having taken an hour to reach launch altitude and separation, the max­imum altitude when SpaceShipOne reached the top of its climb, or its apogee, occurred about 3 minutes after the rocket engine initially fired off. SpaceShipOne stopped moving up at this point and began to free fall back to Earth. The pilot experienced weightless conditions for approxi­mately 3.5 minutes, which he started to feel once the rocket engine shut down. For comparison, the Space Shuttle took 8.5 minutes to go from its launch pad to its orbital altitude of around 200 miles (320 kilometers).

Shot from space, the photograph in figure 3.14 gives a glimpse from SpaceShipOne’s window of the leading edge of its wing high above desert mountains.

While outside the atmosphere, SpaceShipOne could not use its rudders or elevons to control movement whether it was ascending or descending. Since space is a vacuum, there was no air to provide the lift that these control surfaces required to change the spacecraft’s course. This is the same problem faced by the Space Shuttle, as well as other spacecraft and satellites. Even astronauts during extravehicular activity (EVA), floating outside the International Space Station, need a way to steer themselves around. To maneuver in space, they accomplished this by shooting little jets of gas in a direction opposite to that of the intended motion. So, for example, if a spacecraft needed to move to the right, it shot a puff of gas to the left.

SpaceShipOne was no different. In the airless environment, the pilot had to use the reaction control system (RCS) to maneuver SpaceShipOne.

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Fig. 3.15. In an interview with Ed Bradley for 60 Minutes after the Ansari X Prize spaceflights, Burt Rutan shows the feather configuration and describes how it allowed the safe return of SpaceShipOne to Earth’s atmosphere. Mojave Aerospace Ventures LLC, photograph by Scaled Composites

After he switched the RCS on, he used the control stick and rudder pedals to control thrusters mounted on the fuselage and wings.

“We chose to put a microswitch on the end of the travel, so you had to get your knees out of the way just to do anything at all. You had to move the stick all the way to a stop until it closed the microswitch, opened up a valve, and then the jet worked,” Melvill said.

The rudder petals worked the same way, in that they had to be pushed all the way on the floor to activate the thrusters. So, the thrusters would fire as long as the pilot pressed against the microswitches.

After working two years as the director of Bede Test Center for Bede Aircraft, makers of the BD-5J Microjet, Rutan was ready to go it out on his own. In 1974 he founded Rutan Aircraft Factory (RAF) to continue the development of his first airplane, which he began designing back in college and started flying in 1972, and the develop­ment of brand new designs.

“I name very few of my airplanes,” Rutan said. “Even the VariViggen, my first one, was named by a guy at work. I told him I was going to build something that was a lot like the Swedish Viggen, except that it had the feature of variable camber that changed the loading. He said, ‘Okay, how about VariViggen.’” Rutan simply replied, “Okay.”

Although Burt Rutan is well known for the use of composites, the VariViggen’s only use of composites was a fiberglass cowling. The aircraft was made out of wood, and its wings were aluminum. However, it had what would become a hallmark of Rutan’s—a canard. The canard was a small wing forward of the main wing that enhanced lift, allowed for slower maneuvering speeds, and helped prevent stalling. The VariViggen was powered by a pusher propeller at the back of the aircraft and had vertical fins at the wingtips called winglets, which improved the rate of climb and cruising speed. These two features also reoccurred in many of Rutan’s designs. Figure 1.2 shows some of Rutan’s earliest aircraft.

Rutan had begun construction of the VariViggen in his spare time while still working for the air force, and it took him four and a half years to complete it. With only seventy-five hours on the aircraft, Rutan flew the VariViggen to Oshkosh, Wisconsin, to give the public its first viewing during the 1972 Air Venture, the annual fly-in held by the Experimental Aircraft Association (EAA), which is the premiere aircraft organization for homebuilts and experimental aircraft. The crowd thrilled at the futuristic-looking aircraft.

“When you look at the wide variety of his designs from the VariViggen to SpaceShipOne and everything in between,” said Tom Poberezny, the President of EAA, “Burt has been a design leader. He’s always been creative and pushing the envelope.

“If you attend a forum at Oshkosh, it is always a packed house because people want to find out what’s the latest and greatest in Burt’s fertile mind. And that becomes motivational for people in terms of the excitement of being inside of design theory, design thinking, and innovation.”

Rutan gave the VariViggen the tail number N27VV. Characteristic of Rutan, the tail numbers of his aircraft weren’t arbitrary. All U. S. aircraft begin with N, but the “27” stood for the model number Rutan gave it, and VV obviously stood for VariViggen.

Another revolutionary aircraft made its debut at the 1972 AirVenture. The tiny little Rand Robinson KR-1—at a length of 12 feet 6 inches (3.8 meters), a wingspan of 17 feet 2 inches (5.2 meters), and a weight of 310 pounds (140 kilograms)—generated a lot of strange looks and disbelief. Ken Rand’s homebuilt aircraft had started people talking and thinking a little differently about the way airplanes were built. The outer wing panels, vertical and horizontal tail surfaces, and other parts of the aircraft were made using polystyrene—the same stuff foam coolers and coffee cups are made.

Even though plywood, which is technically a composite because it is made of wood layers glued together, was also used to build the fuse­lage, the KR-1 made use of composites like no other aircraft of its time. Polystyrene is very light, but it is also very weak. So, epoxy and cloth made of Dynel, a synthetic fiber, covered the polystyrene in order to give it the rigidity and strength needed to hold together. The KR-1 had a profound influence on the evolution of large-scale use of composite materials in homebuilt aircraft.

Rutan’s next design, the VariEze, also a pusher prop with a canard and winglets, took him only three and a half months to complete by taking the use of composites to a whole new level. “I didn’t have as a goal to build better, lighter, safer, more affordable composite structures. I saw it as a way that I could take a complex aerodynamic shape and build it quickly and get it into flight test,” Rutan said.

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Fig. 1.2. The early aircraft designs and projects of the Rutan Aircraft Factory (RAF) came in many shapes and sizes, including Voyager, AMSOIL Racer, Quickie, Defiant, VariViggen, Grizzly, NGT, Long-EZ, AD-1, Catbird, VariEze, Boomerang, and Solitaire. Provided courtesy of Scaled Composites

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“The KR-1 was a wooden airplane with Dynel and foam to shape its outer shape. Its primary structure was wood—the fuselage and wings and tail—whereas if you took the wood out of it, it would fall apart. The VariEze was different. Its composite was its primary structure.” The composite Rutan had used was polystyrene foam sandwiched between layers of fiberglass. “I started my composite work with moldless methods that I used on the VariEze and the Defiant and a bunch of our airplanes,” Rutan said. “I did that by copying what they did when they did repairs to molded European sailplanes. European sailplanes were made, and still are, in molds.”

But to fix damage to one of these sailplanes, it wasn’t necessary to go back to the mold. “The brainstorm that I had was, ‘Wait a minute, I could build a whole airplane with these repair methods.’ And that’s how I came up with hotwire wing cores and the hand-carved foam for the fuselage box. And sure enough, I built a whole airplane with­out a mold.” Figure 1.3 shows Rutan with a composite panel during the assembly process.

Rutan originally had no intention to sell the VariEze. He built it as a research aircraft to do more testing with the canard concept. But during its introduction to the public at EAA’s 1975 Air Venture, the public went wild for the design. Rutan responded by slightly enlarging the design and selling the VariEze as a kit airplane, so homebuilders could purchase plans and components to build it themselves.

“The VariViggen, the VariEze, all these designs, were unique in the fact that they were out of character from the type of design that was typical of the day,”Tom Poberezny said. “He breaks the mold every time he does something.” Figuratively speaking, of course.

In 1986, Rutan’s Voyager made the first nonstop flight around the world without refueling. It lifted off from Edwards Air Force Base with its tanks full of 7,011 pounds (3,181 kilograms) of fuel, circumnavigated the globe without once landing, covering a distance of 24,986 miles (42,212 kilometers), and then touched down nine days later at Edwards Air Force Base with 106 pounds (48 kilograms) of fuel to spare.

The amazing strength-to-weight ratio of the graphite fiber and honeycomb composite that Rutan used to build Voyager allowed a wingspan of 110 feet 8 inches (33.8 meters) and a primary structure weighing in at only 939 pounds (426 kilograms). Fuel actually accounted for 72 percent of its gross takeoff weight.

It was hard not to notice Rutan’s design and engineering prowess. And soon NASA, defense contractors, and large aircraft manufacturers began knocking at the door. In 1982, the year construction actually began on Voyager, Rutan founded Scaled Composites to specialize in proto­type development, offering design all the way through flight testing of full-scale vehicles or scaled-down versions and models. Figure 1.4 shows early designs that Scaled Composites worked on, including the

Starship, Pegasus, and the Pond Racer. Scaled Composites built some of these designs from start to finish, but for others the company only contributed to part of the construction.

“Things got more conventional,” explained Rutan. “I mean the way we build airplanes. They are still sandwich. They tend to be more honeycomb core than foam core. They tend to prepreg, and we cure them at higher temperatures. We still do them without the autoclave. And we occasionally come up with a breakthrough in manufacturing methods.”

But the manufacturing processes, while important, were never the driving force. As always, it was the design and the need to fly that drove the manufacturing processes. And after about thirty years from the time Rutan graduated college, he started to wonder what was next. Space was never that far from Rutan’s mind, or reach. In his bookshelf was a fat binder that contained original writings of Wernher von Braun. It was the Mars project. Rutan decided, “‘Damn it! Nobody else is going to do this. I’ll do something for space.’ That didn’t dawn on me until about ’93 that if I focused on suborbital, then I could do something interesting.”

Burt Rutan described the idea of the feather maneuver as the pivotal piece of the puzzle needed for the design of SpaceShipOne. Reentry into Earth’s atmosphere was the most critical point of every spaceflight. By deploying the feather mechanism, referred to as “carefree” and “hands – off,” the aerodynamic drag increased substantially, resulting in very low thermal loads. This was because the spaceship slowed down so quickly in the upper atmosphere that when it reached the thick atmosphere, it was traveling with much less energy. Because there was less energy, there was less heat being generated, and SpaceShipOne didn’t get as hot. On ascent after the boost, as SpaceShipOne continued to slow and close in on apogee, the test pilot put the feather up. “We put the feather up because we want to have as much time as possible to troubleshoot if it doesn’t
go up,” Melvill said. “It goes up with two different pneumatic actuators, either one of which can do the job. They are fed out of two separate high-pressure bottles. And you can put both bottles to one or the other. We had redundancy.”

Going up to space had its challenges, but coming back down was where a space program was truly tested. And the feather was SpaceShipOne’s ticket back home. Figure 3.15 shows SpaceShipOne with its feature in the extended position.

“So, we would put it up as soon as we were out of the atmosphere because if we put it up in the atmosphere, we would start doing loops.”

The rear half of each wing folds upward about a hinge line, looking like a jack-knife. It took less than 20 seconds for the feather to deploy to an angle of 65 degrees, and the pilot watched the instrument panel to make sure it went all the way up.

“As soon as you moved the handle, that unlocked it, and as soon as it was unlocked, you’d hear it,” Melvill said. “Without the motor running, it was very quiet. And you would hear it go konk in the back as it unlocked. As soon as we heard that, you would put the feather up with the handle. There were two handles right next to each other on the left side. The feather took a long time, and it made a noise going up. You could hear the air hissing into the large-diameter actuators.”

After SpaceShipOne reached apogee, going over the top, it began to pick up speed and continued to follow a ballistic arc downward much

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Fig. 3.16. The feather extends and retracts by air-powered actuators, or pistons, that are attached on either side of the fuselage and connected to each side of the wing near their trailing edges. Mojave Aerospace Ventures LLC, video capture provided courtesy of Discovery Channel and Vulcan Productions, Inc.

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like the parabola traced by a ball thrown into the air and as it drops back down to the ground.

The spacecraft had a lift-to-drag ratio of about 0.7 in the feathered configuration, so the descent was nearly vertical, with an angle of attack of 60 degrees. While in space, a video camera mounted in SpaceShipOne’s tail boom captured the image of the feather shown in figure 3.16.

Now as SpaceShipOne transitioned from space to reentry, the atmosphere began to get thicker and thicker. Mach 3.25 was the fastest reached by SpaceShipOne. This corresponded to an airspeed below 160 knots equivalent airspeed.

“You come back a little faster than you go up,” Melvill said. “You get a tremendous amount of g-forces on your body when you are coming back. We were looking at 5.5 g’s on reentry.”

The pilot didn’t wear a g-suit. But he did experience a decelera­tion force above 5 g’s for around 10 seconds. Since the pilot sat upright the entire flight and SpaceShipOne reentered the atmosphere belly first, it was critical for the pilot to train beforehand in order to build up his g-tolerance.

“You see because of the rods and cones in your eyes,” Melvill explained. “They need oxygen-enriched blood to feed them. If the blood gets drained down to where there is not much oxygen – enriched blood behind your eyes, you go blind. You just black out. And you can still hear and think and move the stick. But you can’t see. And that would be hard to fly if you couldn’t see.”

In the feather configuration, SpaceShipOne acted like the conical­shaped shuttlecock, or birdie, used in the sport of badminton. Originally made of feathers and now more commonly made of plastic, the shuttle­cock’s skirt has such high drag compared to its base that after a hit from a racket, the shuttlecock automatically orients itself base-first in the direction of flight. The Scaled Composites team took advantage of the two important aspects of this concept when considering the reentry of SpaceShipOne. The high drag caused rapid deceleration, and the self-aligning tendency ensured the proper orientation.

“You don’t even need to do anything coming back down. It is a ‘carefree’ reentry,” Melvill said. “You could put your hands behind your head and take your feet off the rudder pedals and just wait. And you could reenter in any attitude. You could be tumbling when you reenter. You could be upside-down when you reenter. You could be knife-edge and the feather will turn you around and straighten you out. It happens real slowly.”

A terminal velocity of 60 knots equivalent airspeed is reached in this high-drag configuration. This corresponds to a ballistic coefficient,
calculated by using the weight, drag, and cross-section of SpaceShipOne, of 12 pounds per square foot (psf), compared to that of 60 psf for the early Mercury capsules. A low value of the ballistic coefficient means that the spacecraft will begin to slow down quickly in the thin atmosphere. So, SpaceShipOne experiences only low overall structural and thermal loading. It goes from supersonic to subsonic in about a minute and a half.

“The temperature when we reenter around the airplane is very high,” Melvill said. “It is about 1,200 degrees, but that’s the air temperature against the skin. Because that happens at 100,000 feet [30,480 meters] or more, there is so little air to conduct the heat into the structure. The molecules of air are so far apart because it is only 1 percent, or less, atmosphere up there. So, it takes time for that heat to be conducted into the structure, and we’re through that heating period before it has time to get into our airplane. Burt designed it that way, and that was very clever. He made sure that we wouldn’t spend very much time under the conditions where we could melt the airplane.”

During a presentation at the Experimental Aircraft Association’s 2006 AirVenture at Oshkosh, Wisconsin, Rutan described the differ­ence between the thermal protection system of SpaceShipOne and the Space Shuttle: “You don’t have the problems going Mach 4 that you do going Mach 25.

“On the boost, SpaceShipOne sees temperatures that are too hot for the skin at the nose and on the leading edges. That’s all. To be conser­vative, we protected some of the areas that got relatively hot on reentry. That’s why you see that stuff down under the nose and up underneath the wing. However, our measurements there showed that none of that was required. SpaceShipOne doesn’t need any thermal protection at all for reentry. It only needs several pounds of material for boost.”

In cooperation with the U. S. Air Force, SpaceShipOne reentered into restricted airspace controlled by Edwards Air Force Base. But within the restricted airspace, the Office of Commercial Space Transportation (AST) had designated a location, a box roughly 2.5 square miles (6.5 square kilometers) in size, for SpaceShipOne to come down through during reentry.

This was certainly a piloting challenge because in order to reenter through the box, the pilot already had to be in position on the way up. So not only did the pilot have to make sure the wings were level, the nose was pointed up, asymmetries were compensated for, and the occasional wind shear was counteracted, he had to try to position SpaceShipOne so that once the engine shut down and the atmosphere was gone, it would coast more than 100,000 feet (30,480 meters)

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Fig. 3.17. SpaceShipOne returns from space as a glider and makes a horizontal landing similar to way the Space Shuttle does it. Although not the most efficient glider, SpaceShipOne had a glide range of around 60 miles (97 kilometers). Mojave Aerospace Ventures LLC, photograph by Scaled Composites

V_________________ ) feet to apogee, free fall back down, and then drop through a relatively small-sized box.

“Our priorities were we wanted to get altitude, and we wanted to leave the atmosphere without a lot of body rates or gyrations,” Binnie said.

The third goal was to come back inside the box. “But controlling the body rates and maneuvering the vehicle to find that box were kind of at odds with each other.”

SpaceShipOne continued to descend with its feather up. This configuration was so stable that in the atmosphere at the higher altitudes, it was easier for the pilot to just leave the feather up, even though SpaceShipOne had performed a safe reentry. However, there wasn’t much control. The pilot couldn’t pitch the nose and roll the wings, but he was able to change the direction that the nose pointed.

“This is something we didn’t feel necessary to test, but it is likely that you could survive a feather-up landing in SpaceShipOne,” Rutan said. “We did not plan to ride it down if the feather didn’t come down. We planned to jump out.”

At an altitude below 70,000 feet (21,340 meters), the feather was retracted and locked. SpaceShipOne, flying subsonically, transformed into a glider.

“I always had the space bug, keep in mind,” Rutan said. “When did I jump in and do it myself? It came in a time when I thought I could do it. And it wasn’t with SpaceShipOne at first. I was going to do a capsule, and launch it from an airplane that did a steep climb and a parachute recovery.” He began sketching out ideas in 1993.

“I was going to build something to fly out of the atmosphere. I’m not saying the things that I originally laid out were easy. They weren’t easy, but they weren’t really innovative. They were pretty straightforward. It didn’t require anything that was new or patentable or breakthrough in nature.”

His first ideas focused on a single-person rocket carried as an external store by a mothership. The carrier aircraft would pull up and then shoot it off like a missile.

“Around 1995 or so, we were designing and starting to build an aircraft called Proteus,” said Doug Shane, the vice president of business development and the first engineer that Rutan hired at Scaled Composites. An award-winning test pilot himself, Shane also became director of flight operations, which is a position he has held at Scaled Composites since 1989. Figure 1.5 shows Shane in Mission Control with Rutan at his side.

Proteus was a utility aircraft designed to fly at high altitudes above

60,0 feet (18,290 meters), but one of its design requirements was to launch a single-person suborbital rocket. Proteus would perform a zoom maneuver at 27,000 feet (8,230 meters), pulling up to 40 degrees to assist the rocket’s trajectory. Figure 1.6 shows the original launch concept with the rocket attached by an offset mounting, and figure 1.7 shows its separation from Proteus.

When Rutan got word of the formation of the X Prize, well before it was called the Ansari X Prize, he decided to change the design from a single-person capsule to a three-person capsule, which was a condition set forth by the X Prize. Figure 1.8 shows the rocket during ascent and the capsule and booster parachuting down after reentry.

The most important part of the design of the spacecraft was the feather, the little protuberances pointed upward away from the blunt end of the capsule. Acting and looking like the “feathers” of a

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Fig. 1.3. Burt Rutan began his pioneering work with composites on the VariEze, the second air­plane he designed and built. In 1975, the VariEze took him three and a half months to construct, whereas his first airplane, the VariViggen, took more than four and a half years. Mojave Aerospace Ventures LLC, photo­graph by Scaled Composites

к________ ) badminton shuttlecock, the design would accomplish two very important things. First, the high drag would decelerate the capsule very quickly, which would tremendously reduce the thermal loading and the dangers of heat buildup during reentry. And second, it would act to self-right and stabilize the capsule, orienting the capsule’s blunt side down no matter what the attitude during initial reentry. Rutan would call this his “carefree” reentry. This allowed the spacecraft to reenter at a near-vertical trajectory. The Space Shuttle, in comparison, had to precisely control its attitude during reentry, too shallow and it would skip off the atmosphere, too steep and it would experience catastrophic heating.

The capsule would then float down over the water. “I wanted to pick it out while it was still under the chute with a helicopter,” Rutan said.

The method was very similar to the way that film canisters ejected from the very first spy satellites were recovered during Project Corona, the joint effort between the Central Intelligence Agency (CIA) and U. S. Air Force. A film canister would parachute down, and an aircraft with a large catch would swoop by and snag it out of the sky.

“My baseline at first was that if it went into the water it was an unexpected failure or emergency. I wanted to grab them and helicopter them back to the launch site,” Rutan said.

Something about a parachute and helicopter blades make it seem like a bit of an odd combination, though, even for Rutan. “When you work with parachute recovery,” Rutan mused, “you take certain generic risks that you just can’t get around. And I thought I could do it. I think it was a much bigger decision that led me to develop something that could survive a steep reentry and land on a runway and not have to be controlled in attitude during reentry.

“That concept, that design, that approach was much more significant.”

So, the ideas of a capsule and a parachute were scrapped. But air launch was still on the table. Scaled Composites would also stick with

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Fig. 1.4. Scaled Composites built complete aircraft as well as components for many vehicles. Just a few of these are Pegasus,

Starship, Triumph, ATTT, ARES, and Pond Racer. Provided courtesy of Scaled Composites

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using the name “feather” even though the final design looked more like a pair of broken wings.

“If you can buy some time in the event of a propulsion problem instead of being this high off the ground when the motor quits or does something funny,” said Shane while sticking his hand out to his side about four feet off the ground, “if you are at 50,000 feet [15,240 meters], you really have a lot more time to deal with it. It gives you an awful lot more options.”

Early models, like those shown in figure 1.9 and figure 1.10, used a high-drag speed brake and large deflecting elevons as the feather mecha­nism for reentry. And Rutan’s team demonstrated several models where the feather worked subsonically. But when it came to supersonic speeds, like those encountered during reentry, they didn’t trim supersonically. In other words, they were uncontrollable. If the center of gravity (CG) was moved back, they would fly okay, but then they became unstable at sub­sonic speeds. A computerized fly-by-wire flight control system might have made them flyable, but the cost was too high and the reliability too low.

This was an enormous setback. Only two manned, winged vehi­cles had made it to space, the X-15 and the Space Shuttle. Both had fatal accidents during reentry. An X-15 had a flight-control failure in 1967, and the Space Shuttle Columbia had a failure of its thermal protection system in 2003. It was necessary to solve this problem before any more forward progress could be made.

“Finally, maybe it was some spicy food he ate late at night or some other kind of epiphany,” Shane said about Rutan. “He suddenly realized that maybe the thing to do would be to pivot part of the wing and the tails on a hinge on the body and provide that high-drag configuration. And that ended up satisfying all the subsonic and supersonic aerody­namic challenges. That was actually a pretty clever concept, and that’s what we went forward with.”

Figure 1.11 shows the new spacecraft design with the feather deployed for “carefree” reentry.

With the wings returned to the normal flight configuration, SpaceShipOne became a glider. The hard part was certainly over, and the pilot had time to take a breath and take in the view again. But his work was not completely over. Figure 3.17 shows SpaceShipOne gliding over the high desert of Mojave.

If SpaceShipOne was off course during the boost phase, it could be far away from where it needed to land. However, the spacecraft had a glide ratio of seven to one. So, SpaceShipOne had glide range of about 60 miles (97 kilometers) after it defeathered. “It’s got an awful lot of capability to deal with poor trajectory,” Doug Shane said.

The pilot also had to resolve a technical glitch with the global positioning system (GPS) receiver. It would drop out or lose its way during spaceflights. “The GPS receiver was never previously tested in that high and in that fast of a flight regime,” Pete Siebold said. “And so it had software difficulties of its own. The GPS receiver was some­thing you buy from a company off the shelf. It just didn’t perform the way it was supposed to.”

In one of the spaceflights, the GPS receiver reset by itself, but for the other two, the pilot had to reset it.

“So, we had to do a power cycle. The avionics go away while it is booting back up, and then it does a realignment of the inertial navi­gation system once it powers up again. But we could live with that fault. We had workarounds,” Siebold said.

The spaceship glided down for 10—15 minutes and was much lighter now that the oxidizer and fuel were burned off. SpaceShipOne was not able to land safely with a full load of oxygen and fuel. The extra weight changed the balance, and it was just too heavy for the landing gear to take. So, for an abort, it would have to dump all the nitrous oxide, but it still had to manage with the remaining mass of rubber.

Although SpaceShipOne did a good job gliding down and getting close to the airport, it did not have all the controls or responsiveness of a typical glider, so its maneuvering when it came to landing was limited. Early in the program, a few landing attempts were almost too short or too long for the runway.

Pete Siebold and Brian Binnie modified the landing technique, allowing SpaceShipOne to easily compensate for coming in too high or too low. “We would fly at 8,500 feet [2,590 meters] above sea level above our touchdown point,” Siebold said. “And we had a 360-degree turn to make back to that point again, and then we would be lined up for the final touchdown on the runway. The original technique allowed you to vary the radius of that turn. If you were too low, you could decrease the radius, and your circumference was your flight path. And if you were too low, you could make up for being low on energy by flying that tight radius. Or you could widen it out.

“We also had one last-ditch effort to make any adjustments, and that was to put the landing gear down. When the landing gear was up,

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Fig. 3.18. Landing proved to be a bigger challenge than anyone had anticipated. There was only one shot at it. SpaceShipOne had to come in at the right altitude and speed or it risked overshooting or undershooting the runway. Mojave Aerospace Ventures LLC, video capture provided courtesy of Discovery Channel and Vulcan Productions, Inc.

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Fig. 3.19. Once SpaceShipOne touched down, steering was very limited. The nose skid and the rear landing gear’s brakes brought the craft to a quick stop, but since it was unpowered, it needed some help to get off the runway. This photograph shows Sir Richard Branson, Paul Allen, and Burt Rutan (left to right) sitting on the tailgate with SpaceShipOne under tow. Dan Linehan

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it was a seven-to-one glide ratio. With the landing gear down, it was a four-to-one glide ratio. The problem was that once you put it down, you couldn’t put it back up. So, you had to be sure that you had sufficient elevation to make the runway.”

SpaceShipOne would spiral in for a landing while reaching key alti­tude points that were provided by the TONU. An energy predictor similar to what was used during boost showed the pilot where SpaceShipOne would be at the key altitudes based on the current turn and descent rates. The pilot would then adjust his speed and turn so that SpaceShipOne would end up at the place it needed to be.

“After we developed that and utilized it, we landed to within 500 feet [150 meters] of a given touchdown point on every subsequent flight. That was real rewarding,” Siebold said.

SpaceShipOne approached the runway at an airspeed of 140 knots indicated airspeed. But in order to put its gear down, it had to perform a special maneuver. “There were other peculiarities with the gear sys­tem,” Siebold explained. “You couldn’t put it out at your normal approach speed. So, the speed at which you flew the pattern was too fast to put the gear out and too fast to land. So, what you had to do was in your turn from base to final, you actually had to pull the nose up, slow the airplane down, put the gear out, dump the nose, with gear extension at 125 knots, and then speed back up to 140 knots.” Figure 3.18 shows SpaceShipOne gliding down to the runway at Mojave Airport.

The pilot had one last challenge to face. As it turned out, it was one that Charles Lindbergh faced seventy-seven years previously in

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Fig. 3.21. The North American X-15 was the only other manned, winged suborbital vehicle. SpaceShipOne shared some similarities with it, but trajectory was not one of them. The high-altitude and high-speed mission trajectories of the X-15 are shown in comparison to the SpaceShipOne trajectory. Mojave Aerospace Ventures LLC, provided courtesy of Scaled Composites

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Fig. 3.20. The X-15 had enough fuel to power its rocket engine for about 2 minutes, so it required a B-52 to lift it to launch altitude. The X-15 flew from 1959 to 1968, posting a top speed of Mach 6.70, or 4,520 miles per hour (7,270 kilometers per hour), and a maximum altitude of 354,200 feet

(108,000 meters) on separate flights. NASA-Dryden Flight Research Center

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Table 3.2 SpaceShipOne’s and X-15 Suborbital Mission Comparison

Program goals

Number of vehicles in program Crew capacity

Number of rocket-powered flights

Combined time of rocket-powered flights (hours:minutes:seconds)

Number of flights above 100 kilometers (62.1 miles/328,000 feet)

1 st stage

Separation altitude Engine type Oxidizer and fuel Maximum engine burn time Trajectory for boost and reentry Maximum airspeed Maximum altitude Weightless time Reentry method Reentry max q Approach airspeed Touchdown airspeed Landing surface

Number of vehicles lost during flight testing Number of fatalities during flight testing

X-15

High speed and altitude 3 1

199*

30:13:49*

2

NASA B-52 carrier aircraft

45.0 feet (13,720 meters)

Liquid

Liquid oxygen and anhydrous ammonia 141 seconds (high-speed mission)

Approximately 40 degrees (high-altitude mission) Mach 6.70

354,200 feet (108,000 meters)

3.5 minutes

Pilot controlled pull-up

1.0 psf (550 KEAS)

270 KEAS

180 KEAS Lake bed 1 1

the Spirit of St. Louis, which had no front windshield. “The visibility out of SpaceShipOne is pretty restricted, and you got these really small windows, and there is no window in front,” Melvill said. “So, when you are lined up with the runway, you can’t see the runway. With a normal airplane, you can look out the front and see the runway.

“This one, the windows were on the sides, and as long as you were turning toward the runway, you could see it through the side win­dow. But as soon as you lined up with the centerline, you couldn’t see it anymore. The whole airport disappeared. So, that was a little bit
disconcerting I think for all of us. That’s why we had a chase plane sit­ting right on the wing calling out how high we were above the ground and basically keeping us straight as well.”

At 100 to 110 knots equivalent airspeed, the main landing gear at the rear hit first, and then the nose skid followed. There was no real way to steer once it touched down. The wooden tip of the nose skid brought it to a smooth, but slightly smoky, stop in front of an ecstatic crowd. Figure 3.19 shows SpaceShipOne being towed from the runway accompanied by Paul Allen, Burt Rutan, and Sir Richard Branson.

Up to this point, design and development had been relegated to computer analysis and foam models. Burt Rutan hadn’t been ready to approach anyone for funding until he felt ready that he could deliver what he’d promised. Figure 1.12 shows Rutan and aerodynamicist Jim Tighe during early computer analysis.

For the design of SpaceShipOne and White Knight, Scaled Composites would rely heavily on computer analysis because the vehicles would not go through wind-tunnel testing. Figure 1.13 shows an evaluation of SpaceShipOne as the tail booms bend downward.

Around this time, Rutan and philanthropist Paul Allen, who cofounded Microsoft in 1975 with his high school friend Bill Gates, had begun exploring the possibility of using high-altitude airplanes circling over Fos Angeles as a way to provide broadband wireless to the city. “My first couple of meetings with Paul were not about space at all,” recalled Rutan. “There was an interest that he had in something else I was doing. It was related to Proteus for telecommu­nications.” They eventually got around to talking about space, and Rutan’s idea for a very low-cost suborbital spacecraft. Allen turned out to be a bit of a space enthusiast and became quite interested. But Rutan was still not comfortable with his design, which was still based upon a capsule and parachutes at the time.

Once fiber optics took off, using an airborne telecommunications platform was no longer feasible, but Rutan hadn’t stopped thinking about the spaceship. “I figured out the ‘carefree’ reentry, and I thought I could have something that could land as a glider, be more operable, and a lot safer. I didn’t know that ‘carefree’ reentry would work. I just had a good feeling about it.”

In the spring of 2000, Rutan felt he was ready for funding. “I actually asked for a meeting with Paul. And I said, ‘Fisten, I think

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Fig. 1.5. The first engineer that Burt Rutan hired at Scaled Composites,

Doug Shane, was responsible for the flight testing of SpaceShipOne and White Knight. During the flight tests, Shane’s was the cool, calm voice on the Mission Control side of the radio. Mojave Aerospace Ventures LLC, photograph by David M. Moore

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Fig 1.6. Before the design of SpaceShipOne was conceived, Burt Rutan developed a concept for a single-seat rocket to be launched into space off of Proteus, a high-altitude research aircraft.

Fig. 1.7. As Proteus reached launch altitude, it would perform a zoom maneuver by pointing up at a steep angle to assist the trajectory of the rocket on its suborbital flight. Mojave Aerospace Ventures LLC, provided courtesy of Scaled Composites

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I could do this now.’ And he put out his hand and shook it and said, ‘Let’s do it.’”

Like many kids growing up in the late 1950s and 1960s, Allen remembered the television cart being wheeled into his classroom to watch Mercury, Gemini, and Apollo launches. Science and technology had fascinated him whether he was building model rockets or reading science fiction. “I always had in the back of my mind, would I ever have the opportunity to do something in a space-related initiative?” Allen recalled. “And so when the SpaceShipOne opportunity came up, I was very excited to pursue it.”

Paul Allen’s company, Vulcan, Inc., and Scaled Composites began a partnership called Mojave Aerospace Ventures. Although Allen and Rutan were aware at the time of the creation of the X Prize by Peter

Diamandis, their initial goal, however, was getting to space and not necessarily winning the X Prize.

“None of these meetings were about the X Prize,” Rutan said. “People think we did the program for the X Prize. But keep in mind, the X Prize wasn’t even funded until halfway through our program. And, in fact, I had an opinion that Peter Diamandis would never get the funds for it. So, we had written him off.”

By the time the partnership was finalized a few months into 2001 and Allen provided the funding to Rutan, winning the X Prize had also become a goal of Mojave Aerospace Ventures. “There were two ways for me to recoup my investment,” Allen said. “One was the winning of the X Prize, and one was the licensing we’d be able to achieve with a company like Virgin Galactic. Those were the possible

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Fig. 1.8. After completing the boost, the capsule separated from the booster. It is here where Burt Rutan first applied the idea of a feathered,

"carefree" reentry. Small arms pointing upward from the capsule would safely decelerate and steady the capsule during reentry. Mojave Aerospace Ventures LLC, provided courtesy of Scaled Composites

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Fig. 1.9. Because of Burt Rutan’s decades of experience designing aircraft, he decided to abandon the idea of a rocket and parachutes.

His next designs focused on winged aircraft that could make horizontal landings on a runway.

Fig. 1.10. Still called a feather, early winged designs used large spoilers and elevons for reentry. Below the speed of sound this configuration worked. However, reentry occurred above Mach 1, and these configurations could not be controlled. Mojave Aerospace Ventures LLC, provided courtesy of Scaled Composites

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future mechanism of payment back when we were evaluating all this stuff. You didn’t necessarily assume you were going to win. And you didn’t know what the other competition was like.”

Now things started to move full speed ahead.

Preparing SpaceShipOne for its next spaceflight was a relatively simple task that required only minimal maintenance. The spent compo­nents of the rocket engine were replaced with fully fueled components, and the oxidizer tank was refilled. The air bottles used to activate the feather and run the reaction-control system and other systems had to be recharged. The ablative coating for the thermal protec­tion system was restored. And since every flight was an envelope expansion, theTONU was updated after a thorough review of the flight data.

X-15 Comparison

The North American X-15 was the first of three winged vehicles ever to have reached space, the Space Shuttle and SpaceShipOne being the other two. The basic mission profile was similar for these vehicles in that they all used two stages to reach space and glided back to Earth for an unpowered landing. However, the X-15 and SpaceShipOne shared much more in common compared to the Space Shuttle, which was a fully operational spacecraft designed to transport large payloads back and forth from orbit, whereas the other two were research and proof-of-concept vehicles that only reached suborbital altitudes.

Originally conceived in 1954, the X-15 first flew in 1959 and flew the last time in 1968. Its two primary goals were to fly at Mach 6— hypersonic speeds begin at Mach 5—and reach an altitude of 250,000 feet (76,200 meters). The X-15’s 199 powered flights directly influ­enced the Mercury, Gemini, Apollo, and Space Shuttle space programs as well as the U-2 and SR-71 reconnaissance aircraft.

Table 3.2 shows a comparison between the X-15 and SpaceShipOne.

To conserve fuel, the X-15 was dropped from the wing of a NASA B-52 carrier aircraft at an altitude of 45,000 feet (13,720 meters), as shown in figure 3.20. For its high-altitude mission, the rocket engine burned for up to 2 minutes, and then the X-15 returned from space and glided in for a landing.

This trajectory flown by the X-15 was, however, quite a bit differ­ent from that flown by SpaceShipOne. Figure 3.21 shows the trajecto­ry flown by SpaceShipOne and compares it with both the high-speed and high-altitude trajectories of the X-15.

The most apparent difference was in the profile width of the X-15 high-altitude mission and the SpaceShipOne mission. The X-15 had to cover 331 miles (533 kilometers) in order to reach an apogee above 62.1 miles (100 kilometers), whereas SpaceShipOne only needed 40 miles (64 kilometers) to accomplish the same feat.

Both had the same amount of weightless time and view, but the X-15 traveled much faster to achieve this. The higher speeds meant greater aerodynamic loads and thermal protection require­ments. But the most important difference was that the X-15 had to expend much more energy to reach the same altitude. The greater the energy needed to get from point A to point B, the more expensive it is to fly.

Primarily constructed of lightweight, high-strength titanium, it had skin of Inconel X, a chrome-nickel alloy that would withstand temperature as high as 1,200 degrees Fahrenheit. The black coating helped dissipate heat, and it was necessary to design gaps into the fuselage to allow for temperature expansion, which was a feature carried over to the SR-71.

A liquid oxygen oxidizer and an anhydrous ammonia fuel powered the liquid rocket engines, providing a thrust of 28,000—57,000 pounds-force (125,000—254,000 newtons). A reaction-control system that used hydrogen peroxide thrusters on the nose and wings allowed the X-15 to maneuver outside the atmosphere.

Another similarity was the landing gear. To reduce weight and simplify the design, the X-15 used two landing skids at the rear of the vehicle, compared to the single skid at the nose used by SpaceShipOne.

On August 22, 1963, the X-15 set an altitude record of 354,200 feet (108,000 meters). Four years later, on October 3, 1967, a high­ly modified version renamed the X-15A-2 set a speed record of Mach 6.70, or 4,520 miles per hour (7,270 kilometers per hour). The entire aircraft had to be covered in a white ablative coating to increase the thermal protection of the skin up to 2,000 degrees Fahrenheit. This was a peak speed, and the X-15 could only run its engine for about two minutes. However, if this speed could be maintained, it would be possible to travel the distance from New York City to Fos Angeles in just over a half an hour.

Although it was a tremendously successful program, four major accidents occurred. One of them claimed the life of test pilot Michael Adams due to a control-system failure during reentry. This accident and the Space Shuttle Columbia accident, also occurring during reentry, were key influences that drove Rutan to develop the “carefree” feather reentry.

Although White Knight began flying about a year before SpaceShipOne, construction of both vehicles began at about the same time. High strength, lightweight composites of carbon fiber/epoxy were used to build the primary structure of both vehicles. Tyson V. Rininger

Burt Rutan does not release much information about a newest aircraft while it’s under development. In fact, it is usually not until the aircraft is ready to fly that people finally get a glimpse of his newest project. The in-house name of their secret space program was Tier One. This name wasn’t uncommon to Scaled Composites. Rutan used “tier one,” “tier two,” and “tier three” to designate what he described as the “fun factor” of a program. When tier-one programs came around, the company would always bid on them, since they were highly motivational programs for his employees, which helped him retain his skilled staff while being out in the middle of a great big desert. Scaled Composites normally used the aircraft’s name as the in-house program name. But this program of course had two vehicles.

“I was making a point to my employees that this was going to be the most fun program that we’ve ever done and the most important one for us to do,” Rutan said.

“That was the original reason behind calling the SpaceShipOne program Tier One. Later on when we started to entertain if we should do other manned spacecraft, I just had a feeling that I should make a category for different basic areas of manned spacecraft. Because it seemed like a good breakdown, I defined that if we do programs in the future that send people to Earth orbit, it would be called Tier Two. If we do things that send people outside of Earth orbit to other heavenly bodies like the Moon and Mars, it would be called Tier Three.”

The spacecraft and the carrier aircraft needed names, too. The spacecraft was Rutan’s Model 316, and the carrier aircraft was Model 318. “Those I assign when I first look at the requirements and
have the first idea of what would be the configuration solution. Those model numbers were assigned years before we had a funded program for building.”

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Fig. 1.11. The feather mechanism, the most innovative feature of SpaceShipOne, allowed the rear half of the wings and the tail booms to fold upward, which prevented dangerous heat buildup upon reentry but enabled a very stable descent. Mojave Aerospace Ventures LLC, provided courtesy of Scaled Composites

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Fig. 1.12. Since wind-tunnel testing was not part of the design and development of SpaceShipOne because of the large expense, Scaled Composites used a computer method called computational fluid dynamics (CFD) to model the aerodynamics. The photograph shows designer Burt Rutan and aerodynamicist Jim Tighe reviewing a computer analysis of SpaceShipOne. Mojave Aerospace Ventures LLC, photograph by Scaled Composites

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SpaceShipTwo and its launch aircraft are Models 339 and 348, respectively.

Rutan added, “We’ve only flown thirty-nine manned airplanes. Most of the concepts don’t get funded and developed.”

One example of this is Model 317. This was the design that squeaked between theTier One spacecraft and its mothership. A new – concept vertical takeoff and landing (VTOL) light aircraft, the tail-sit­ter would take off like a helicopter but fly conventionally.

White Knight was named by Cory Bird, an employee of Scaled Composites who also flew as a flight engineer in the carrier aircraft on several of the test flights. Bird had made a drawing of a knight in white armor, which Rutan thought was very clever. The drawing ended up being the insignia for White Knight, too.

And although Rutan names very few of his airplanes, the spacecraft was an exception. “I wanted to make a point that other manned systems that carried people into space tended to be capsules or spacecraft. But if you read fantasy that kids do, it’s always a spaceship. And I thought this is interesting in that there has been a lot of manned spacecraft, capsules, and vehicles, and all these boring names. I felt that this might be the first thing that flies people into space, that you have the moxie to call it a spaceship.”

So, since he considered it the first spaceship, he mixed the words around with numbers. “And I thought, I don’t have any problem

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Fig. 1.13. By using computer analysis, Scaled Composites was able to evaluate the aerodynamic characteristics of SpaceShipOne even before construction got started. However, it was still necessary to test SpaceShipOne in flight to get the complete picture. Mojave Aerospace Ventures LLC, provided courtesy of Scaled Composites

V_____________________________ ) calling this SpaceShipOne because I want to build a SpaceShipTwo, and I want to build a SpaceShipThree.”

Figure 1.14 shows SpaceShipOne mated up to White Knight before the public unveiling and even before paint schemes were added.

In order to be able to fly, though, SpaceShipOne and White Knight each needed a tail number, which is unique identification that every aircraft has similar to a car’s license plate, and had to be registered with the FA A. SpaceShipOne was given N328KF, which stood for

328,0 feet, the boundary line between Earth’s atmosphere and space, while White Knight was given N318SL, where the 318 model number and the SL stood for spaceship launcher.

“We didn’t get our first choices on that,” Rutan said. “For example, I wasn’t particularly enamored by 328KF. I would have rather had 100KM, 100 kilometers. But it was taken.”

Along with the tail number, the type of aircraft had to be identi­fied to the FA A. White Knight was pretty straightforward, but SpaceShipOne wasn’t so clear cut. The FA A felt that commercial launch licensing was required for SpaceShipOne. This was a somewhat long and drawn-out process. So as not to delay flight testing, Scaled Composites initially registered SpaceShipOne as a glider. This made perfect sense because about half the time during a spaceflight SpaceShipOne was a glider. But more importantly, the initial flight test­ing would be done without a rocket engine. So, by calling it a glider first, Scaled Composites was able to buy some time before having to get their commercial launch license, even though Rutan had no intention of using SpaceShipOne commercially.

“When I was out in Mojave for the first-time flight of the X Prize that Mike Melvill flew, it was the first time I had a chance to spend some time with Burt’s design team,” Poberezny said. “And what was striking was the intelligence that he recruited, the youth and the motivation. In other words, they were hungry and they were motivated to be successful and to make a difference. So, I give Burt a lot of credit. When he saw talent, he brought them in.”

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Fig. 1.14. Shown before their paint schemes were added, SpaceShipOne and White Knight share virtually identical cockpits and instruments. But where White Knight has jet-engine controls, SpaceShipOne has rocket-engine controls. Mojave Aerospace Ventures LLC, photograph by Scaled Composites

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Rutan gave direction and vision to his staff but still allowed them to exercise their own strengths and abilities. And Rutan would depend on the contributions of the entire team at Scaled Composites to get SpaceShipOne into space.

On April 18, 2003, slightly more than two years after receiving Paul Allen’s backing, Rutan was ready to go public. SpaceShipOne could no longer be hidden away in Scaled Composites’ hangar. All the compo­nents ofTier One were in place, and SpaceShipOne was ready for flight testing. Figure 1.15 shows SpaceShipOne after the curtain dropped.

White Knight had been flying since August 2002. It was strange enough looking, yet similar enough to the way-out look of Proteus that Scaled Composites didn’t worry too much about it occasionally being spotted ahead of time. Both these aircraft have been widely described as looking like giant prehistoric insects or spaceships from Star Trek.

It would be a full month, though, before SpaceShipOne would take to the air for the first time. However, Rutan had a surprise in store for his guests at the coming-out party. He had White Knight do fly-bys for everyone gathered at the flightline in front of the Scaled Composites hangar. Figure 1.16 shows Proteus, the original spaceship launcher, and White Knight, the new spaceship launcher, flying together, and table 1.1 gives the specifications for White Knight.

Aside from the two vehicles, the other important Tier One compo­nents were revealed, refer to figure 1.17.The test stand trailer (TST) was a partial mockup of SpaceShipOne used to develop the rocket engine. A tanker truck called the mobile nitrous oxide delivery system (MONODS) supplied the nitrous oxide (N20) to the oxidizer tank on the TST and in SpaceShipOne. And the Scaled Composites unit mobile (SCUM) truck was used for ground control, providing

Table 1.1 White Knight Specifications 82 feet (25 meters)

468 square feet (43.5 square meters)

60 inches (152 centimeters) for maximum outer diameter

19.0 pounds (8,620 kilograms) at takeoff with SpaceShipOne

one pilot (front seat) and two passengers (back seat) "short-sleeved" pressurized cabin two J-85-GE-5 turbojets with afterburners 7,700 pounds-force (34,000 newtons)

JP-1

6,400 pounds (2,900 kilograms)

8,000-9,000 pounds (3,630-4,080 kilograms)

53.0 feet (16,150 meters)

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Fig. 1.16. Proteus, flying below White Knight, first took flight in 1998 and was originally planned as the carrier aircraft for a single-person rocket. As the spacecraft design evolved into SpaceShipOne, the larger White Knight was required. Mojave Aerospace Ventures LLC, photograph by Scaled Composites

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a telemetry link with the TST during rocket-engine testing or SpaceShipOne during a flight.

The last component, shown in figure 1.18, was the flight simulator, which Scaled Composites specially designed for Tier One. It was the first flight simulator Scaled Composites ever built and used for one of their aircraft.

Having a sponsor instead of a customer, building with a robust design approach, performing incremental testing, incorporating as many similarities between SpaceShipOne and White Knight as possible, and conducting extensive pilot training in the flight simulator, White Knight, and Extra 300 aerobatic plane would all prove key factors upon which the success of Tier One would depend.

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Fig. 1.17. Tier One, the space program of Scaled Composites, comprised SpaceShipOne, the spacecraft; White Knight, the carrier aircraft; test stand trailer (TST), the rocket-engine testing platform; mobile nitrous oxide delivery system (MONODS), the nitrous oxide (N20) supply tanker; and Scaled Composites unit mobile (SCUM) truck, a ground-control station. Mojave Aerospace Ventures LLC, photograph by Scaled Composites

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Fig. 1.18. Jeff Johnson, project manager for Mojave Aerospace Ventures, sits at the simulator control desk and monitors the progress of a simulation. One of the most critical components of Tier One was the flight-training simulator. Primarily designed by Pete Siebold, it allowed the test pilots to practice and refine the techniques required to fly the challenging trajectory of SpaceShipOne. Mojave Aerospace Ventures LLC, photograph by David M. Moore

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On November 22, 2001, Steve Bennett’s Starchaser team, based in the United Kingdom, became the first competitor to launch a vehicle while displaying an X Prize logo. The single-person Nova capsule, unmanned at the time, rode atop the Starchaser 4 booster. The rocket reached a height of 5,541 feet (1,689 meters). Courtesy of Starchaser Industries