Category Space Ship One

Peter Diamandis

Like many people, Peter Diamandis’ fascination with space began back when he was a child. But unlike many people, he has not stood idly by waiting for the stars to come to him. His obsession with the point where gravity loses its touch, and the places beyond, firmly took root while he was an aerospace engineering student at Massachusetts Institute of Technology. He had the chance to meet astronauts-in-training back then, but this forced the realization that his chances of becoming an astronaut himself were remote and that even if he did make it as one, he would fly to space maybe twice in a decade. Figure 2.4 shows Diamandis as SpaceShipOne made its way to space on October 4, 2004.

The government space programs do work well in specific ways, but very few people will ever get the chance to go up. “That wasn’t my vision of spaceflight,” Diamandis said. “I wanted to go as a private pioneer in my own ship whenever I wanted to go.”

Dennis Tito spent $20 million to fly to the International Space Station (ISS) aboard a Russian Soyuz in 2001, becoming the first

Peter DiamandisПодпись:Подпись:B. IL Aerospace Technologies D. ARCA

F. Suborbital Corporation

Fig. 2.3. The competitors pursued many different approaches, although not every one managed to launch hardware. Concepts were either ground-launched or air-launched, and while most were rockets, many were space planes, with the exception of one flying saucer that would ride upon "blastwave" pulsejets. The air – launched vehicles were either carried or towed by an aircraft or lifted by a giant balloon. The methods of reentry were just as varied. X PRIZE Foundation

Fig. 2.5. Atlantis, Discovery, and Endeavor are the remaining three operational Space Shuttles. First launched on April 12, 1981, exactly twenty years after Cosmonaut Yuri Gagarin’s first-ever spaceflight, the Space Shuttle had been the only U. S. vehicle to carry people into space for twenty-three years prior to the spaceflights of SpaceShipOne. Six Space Shuttles were built, although the first Space Shuttle, Enterprise, never reached space. In 1986, Challenger exploded during liftoff, and in 2003, Columbia broke apart during reentry. Dan Linehan

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Fig. 2.4. Peter Diamandis, the founder of the X Prize Foundation, gives the thumbs up as SpaceShipOne makes its way up to space during the second Ansari X Prize flight.

After reading The Spirit of St Louis by Charles Lindbergh, Diamandis was inspired to create a space prize modeled after the early aviation prizes.

Dan Linehan

Peter DiamandisPeter Diamandis

Peter Diamandisf ^

Fig. 2.6. Thousands and thousands of space enthusiasts crowded into the high desert of Southern California to watch the spaceflights of SpaceShipOne as Mojave Airport transformed into a spaceport. Mojave Aerospace Ventures LLC, photograph by David M. Moore

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paying space tourist. Diamandis has reported that the cost to fly the Space Shuttle, shown in figure 2.5 preparing to launch to the ISS, has ranged from $500 million to $750 million for just one flight, of which propellants make up only 1 percent of that cost. These figures keep the gate to the space frontier shut pretty tight for most people. There just had to be another way.

While flying together over the Hudson River in 1994, Gregg Maryniak, a longtime friend and business partner, wondered when Diamandis would also get his pilot’s license. Diamandis had already stopped and started several times. This was unusual, considering Diamandis’ deep desire for space. One might expect that for someone with dreams of traveling among the stars, a pilot’s license was a good thing to have. But as history continues to remind us, the shortest distance between point A and point В is not necessarily a straight line. Diamandis was far too consumed with what was well beyond where the air is thin.

“Gregg asked me if I had ever read The Spirit of St. Louis,” Diamandis said. Maryniak had explained that he received the book as a gift, and it helped motivate him to finish his pilot’s license. Shortly after their flight, Maryniak gave a copy of The Spirit of St. Louis to Diamandis. But if anything, the book proved to sidetrack Diamandis, resulting in the unanticipated consequence of drastically changing not only how people reach space but also who gets to go.

“As I read that book, I had no idea that Lindbergh crossed the Atlantic to win a prize and that nine different teams had spent $400,000 to win the $25,000 prize,” Diamandis said. “And by the time I finished reading the book, the whole idea of the X Prize had come to mind.”

What Diamandis realized was that a prize could be the catalyst needed for the development of a new breed of spacecraft that could demonstrate the public’s desire for commercial spaceflight. “We needed a paradigm shift,” Diamandis said. “People had become so stuck in their way of thinking that spaceflight was only for the government—only largest corporations and governments could do this—it could never be done by an individual. This thinking was paralyzing us, and that was what I was trying to change.”

When Lindbergh made his famous crossing, the airplane had been in existence for a little more than two decades. It was still a novelty. Some enterprising individuals foresaw the economic advantages of aviation, while others stoked the fanfare and fervor. As a result, hundreds of aviation competitions were established to see who could fly the farthest, the fastest, the highest. It was as much about pushing the limits as it was about drawing boundaries where none had ever existed.

At a time when aviation was in its infancy, prizes and competi­tions put its growth on afterburners. And during these times, people could look in the mirror and see themselves in the cockpit, goggles drawn and wrapped in a scarf, without having to use too much imagination. Although some of the flyers were wealthy and privi­leged and others had renown and notoriety, Charles Lindbergh, an airmail pilot, and others like him, proved aviation was in reach of the common person.

Diamandis saw this vision, only with rocket ships and space helmets. His passion was contagious. He energized many talented and dedicated people who joined this march toward space, contributing thousands and thousands of volunteer hours along the way. Figure 2.6 shows the crowds who gathered to share in this vision.

Apogee to Atmosphere

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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Apogee to AtmosphereFig. 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)

Apogee to Atmosphereг >1

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.

1927: New York to Paris

In 1919, Raymond Orteig created the Orteig Prize for the first non­stop flight across the Atlantic Ocean from New York to Paris or from Paris to New York. Orteig, born in France, owned hotels in New York City. Prizes had been enticing aviators and aircraft makers for a decade now. Newspapers sponsored them because it gave their readers something exciting to read. Businesses sponsored them because they saw financial opportunity.

Aviation technology was not up to the challenge, and Orteig had to extend the deadline of the prize. Come 1926, still no one had claimed the prize. Only one team made an attempt, but they crashed on takeoff.

On May 20, 1927, with only 20 feet (6 meters) to spare, the Ryan NYP Spirit of St. Louis cleared the telephone wires a short distance from the edge of the runway at Roosevelt Field on Long Island. Charles Lindbergh, shown in figure 2.7, had just lifted off for his first solo attempt at crossing the Atlantic Ocean. Several failed attempts had already been made by other competitors by now. Nine teams were in the race to win the $25,000 Orteig Prize. Four men had died trying, and two others, setting out together right before Lindbergh, were lost over the Atlantic.

To make the journey, Lindbergh would have to strip the plane down to the bare minimum to maximize the amount of fuel he could carry. Table 2.1 shows the specifications of the Spirit of St. Louis. So much of the aircraft was gas tank, by design, that Lindbergh had to use a periscope to see directly ahead of the aircraft because a gas tank in front

1927: New York to Parisг———————————————————-

Table 2.1 Spirit of St. Louis Specifications

Ryan Airlines Company highly modified M-2 46 feet (14 meters)

27 feet 8 inches (8 meters)

Подпись: *Подпись: Manufacturer: Type: Wingspan: Length: Height: Empty weight: Gross weight: Engine: Power:

1927: New York to Paris

9 feet 10 inches (3 meters) 2,150 pounds (975 kilograms) 5,135 pounds (2,330 kilograms) Wright Whirlwind J-5C 223 horsepower

1927: New York to Paris

Подпись: Г Fig. 2.7. In 1927, Charles Lindbergh, an unknown airmail pilot, reshaped aviation after crossing the Atlantic Ocean nonstop in an aircraft for the first time, as he flew the Spirit of St. Louis from New York to Paris. The solo flight took 33.5 hours to complete and covered 3,610 miles (5,810 kilometers). X PRIZE Foundation

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Fig. 2.8. The Spirit of St. Louis was specially designed by Charles Lindbergh to make the transoceanic flight. Much of the aircraft was a fuel tank, leaving little room for anything else. Lindbergh had to use a periscope to see in front of the airplane, and he elected not to bring a parachute or radio, to save weight. NASA-Langley Research Center

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of the cockpit blocked the view forward. In a plane that weighed 2,150 pounds (975 kilograms) empty, it carried 451 gallons (1,710 liters) of fuel for a total takeoff weight of 5,135 pounds (2,330 kilograms).

Back in 1927, if you went down in the water, you were gone. There was no satellite tracking, there were no helicopters or airplanes that you could signal. There was no radar. And shipping was nothing like it is today, so rescue from a nearby vessel was highly unlikely. When Lindbergh got behind the controls of that plane and took off, he was all alone with only the vastness of the Atlantic Ocean more than willing to catch him if he fell. And there was less than just a slim chance of him not making it back.

So, the Spirit of St. Louis, shown in figure 2.8, didn’t have a radio, navigational lights, or gas gauges. Lindbergh didn’t even bring a parachute. A radio didn’t do any good over the middle of the ocean and, back in those days, was a lot of weight. The same held true for the navigational lights when the wiring was also factored in. Even gas gauges were redundant, since there would not be much he could do about it if the tanks went dry. But the reverse argument could be made. Each of these could help his chance of survival under some specific circumstances. What if a ship was nearby? Lights and a radio could certainly help. What if he was over land? He should be able to make an emergency landing, but there were circumstances where
bailing out was not out of the question. Lindbergh had to balance the potential benefit of each safety item with the problems he would potentially face if he ran out of fuel. And that’s how he decided.

“He was thinking his way all the way around the problem, though,” said Erik Lindbergh, the grandson of Charles Lindbergh. “I think he minimized every possible risk he could except for lack of sleep. And if he had had a good seven hours worth of sleep, he would have really changed his risk factor.”

Lindbergh didn’t even use a typical leather pilot’s seat. Instead, he used a wicker chair. He did, however, equip himself with four sandwiches, two canteens of water, and an inflatable, rubber life raft.

Lindbergh believed that for a multi engine aircraft, there was only a greater risk of an engine failure, even though most of the other competitors were using that type of aircraft. Today, a Boeing 767 flies overseas with only two engines. If one fails, it still has enough power to reach land by either turning around or by continuing on, whichever distance is shorter. That wasn’t necessarily the case for the multi – engine aircraft of that time.

“He was doing things like cutting the corners off of his map, which is really a negligible weight,” said Erik Lindbergh. “And yet when you look at the competitors, some of them had champagne and croissants on board so they could party when they got there. But they never made if off the ground. So, attention to detail and reducing the risk factors was critical to him surviving the flight.”

Charles Lindbergh became an instant international hero on the evening his wheels touched down in Paris. And people’s interest in aviation exploded. Charles Lindbergh said, “I was astonished at the effect my successful landing in France had on the nations of the world. To me, it was like a match lighting a bonfire.”

Erik Lindbergh said of his grandfather’s accomplishment, “Before he flew across the Atlantic, people who flew in airplanes were known as barnstormers and daredevils and flying fools. And after he flew across the Atlantic, people who flew in airplanes were known as pilots and passengers. It truly was a paradigm shift if there ever was one.”

As a result of this new popularity, referred to as the Lindbergh boom, in the United States the number of applications for a pilot’s license tripled and the number of licensed aircraft quadrupled during 1927. The number of passengers flying aboard U. S. airlines also dramatically increased from 5,782 in 1926 to 173,405 in 1929. Nowadays, the aviation transportation sector is a $300 billion industry.

Gliding to Mojave

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,

Подпись: лGliding to MojaveҐ

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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Gliding to MojaveFig. 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

Gliding to Mojave

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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

Gliding to Mojave
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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

Подпись: SpaceShipOne Altitude and view 1 3 6 2:07:26 3 White Knight carrier aircraft 47,000 feet (14,330 meters) Hybrid Nitrous oxide and rubber 84 seconds Nearly vertical Mach 3.25 (on reentry) 367,500 feet (112,000 meters) 3.5 minutes "Carefree" (60-degree angle of attack) 80 psf (160 KEAS) 140 KIAS** 105-110 KIAS Runway 0 0

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

*ln two of these flights, the rocket-engines were not ignited. One was a planned glide flight while the rocket-engines failed to ignite for the other. **Knots indicated airspeed

Gliding to Mojave

 

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.

The X Factor

Now that the idea was hatched, what to name it?

“The letter X initially stood for the variable for the person’s name that funded the prize, just like the Orteig Prize,” Diamandis said. “It worked because $10 million was the number I thought was the right number. I wanted it to be enough money to be of substantial importance to the world, but not so big that it would attract the Lockheeds or Boeings. I didn’t want the winner to be a traditional player. I wanted it to be somebody who was going to really work hard on how to do this thing cost effectively and worry about every penny spent.”

Finding a title sponsor to put up the prize money proved very difficult, so the X hung around for a lot longer than Diamandis had anticipated. But when the title sponsor did come along, the Xhad already become symbolic. X stood for the Roman numeral ten, as in

A N S A R I

The X Factor

PRIZE

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Fig. 2.9. Initially, the X in the X Prize was only a place holder to be replaced when Peter Diamandis found a title sponsor. But gradually it took on its own significance. X stood for $10 million, X had been used for the early X-planes, and X meant mysterious or extreme. So, when a title sponsor did come along, the X remained. X PRIZE Foundation

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the number of millions in the prize. X denoted a vehicle of an exper­imental nature, as with the X-planes. X also had the connotation of being extreme or mysterious. “So, after we found the Ansaris,” Diamandis said, “we decided to keep it and make it the Ansari X Prize.” The logo is shown in figure 2.9.