Category Space Ship One

Mechanically, the most complicated system on SpaceShipOne was its feathering system. It was also the most important system on board for ensuring the safety of the pilot and the success of the mission. Rutan already had experience with movable-winged aircraft. His RAF analyzed the designs and loads for NASA’s scissor-wing AD-1 (refer to figure 4.13).

Before SpaceShipOne reentered the atmosphere, the aft section of both wings, including the tail booms, rose up as if the spacecraft were almost folding in half. With the feather extended, SpaceShipOne could reenter the atmosphere with very little pilot input required. This “carefree” reentry was one of the most important elements of Scaled Composites’ entire space program.

The feather is a separate structure from the forward wing sections and has its own spars and ribs. However, the aft wing sections and the tail booms do not move independently. Figure 4.14 shows the spar that runs through the fuselage from one end of the movable wing to the other, tying the feather all together.

Left and right pneumatic actuators, which are just cylinders with movable pistons, used air power to pivot the feather up or down along the hinge. The lower ends of each actuator are attached to the fuselage, and the upper ends are attached to the inner face of the aft wing section, as shown in figure 4.15.

There are just two positions of the feather, up or down. The angle the feather makes with the fuselage is preset to 65 degrees, so the pilot did not have to make any adjustments. It took about 13—14 seconds to raise or lower. The feather could be elevated on ascent once the airspeed was less then 10 knots equivalent airspeed. Figure 4.16 shows the 60-degree angle of attack for SpaceShipOne descending in the feather condition.

When the feather got to the fully extended position, there was no lock. It was just the force from the actuators that held the feather up. “As it turns out, it takes no load to put it up because you are weightless,” Rutan said. “When you are weightless, there are no aerodynamics. It takes no force. In fact, if you would unlock it in space, you could take a little cable and pull it right up. There is no load on it. Okay. But, you need to hold it up for reentry.” The reentry force on the flight test actually tried to push the feather down.

If the feather were to move or become disengaged at the wrong time, the results could be disastrous. To keep the feather in the retracted position and to keep it from moving during the other phases of flight, two I-shaped clasps from the locking system secure the trailing edges of the aft wing sections. To unlock the feather so it could be deployed, separate pneumatic actuators were pressurized to retract the clasps.

The design had built-in redundancy for the components that make up the feather system. The two clasps were coupled so they moved together. But they had separate pneumatic sources, lines, regulators, valves, and again, separate actuators. “So, I could have a fire. I could have a line come off. I could have a loss of pressure. I could have all of these things go wrong, and it doesn’t affect the other,” Rutan said.

The two different pressure sources could run either actuator. The redundancy of the locking system was identical to the redundancy of the elevating systems. They were two independent systems that, under normal conditions, acted in unison. However, either system could engage or disengage the clasps of the other system. Once SpaceShipOne was flying subsonically after reentry and the loading drops below 1.2 g, the pilot could retract the feather.

The fourth flight of SpaceShipOne was scheduled to be a glide flight. Figure 7.4 shows preparations being made the day before the flight. Melvill had successfully opened more than 60 percent of the subsonic flight envelope on the previous flight. This included speeds from stall to 150 knots. Now it was planned to open up the envelope even further.

The flight envelope indicated all the ways SpaceShipOne could safely fly, which included variations and combinations of speed, altitude, attitude, and other factors. The crews flew the easiest stuff, as the pilots and engineers gained confidence and began to nail down the flying characteristics. Step by step, they pushed the boundaries as they flew the vehicle more aggressively to reveal its limitations.

However, twenty minutes prior to separation, the launch had to be aborted due to a GPS malfunction with the avionics system. Figure 7.5 shows the mated pair during the aborted test flight prior to landing. Initially designated as 4G and 31L for SpaceShipOne and White Knight, respectively, the flight numbers were modified to 4GC and 31LC as a result of the abort. But it was possible to complete some systems testing prior to landing.

Flight Test Log Excerpt for 4GC

Date: 27 August 2003

Flight Number Pilot/Flight Engineer

SpaceShipOne 4GC Mike Melvill

White Knight 31LC Brian Binnie/Cory Bird

Objective: Second glide flight of SpaceShipOne. Flying qualities and performance in the spaceship feather mode. Pilot workload and situational awareness while transitioning and handling qualities assessment when reconfigured. As a glider, deep stall investigation both at high and low altitude and envelope expansion out to 200 knots and 4 g’s. Lateral directional characteristics including adverse yaw, roll rate effectiveness and control, including aileron roll and full rudder sideslips.

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Fig. 7.4. SpaceShipOne and White Knight are poised before the fourth test flight. Planned as SpaceShipOne’s second glide flight, the flight had to be aborted midair. Mojave Aerospace Ventures LLC, photograph by David M. Moore

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Fig. 7.5. It was necessary to abort the fourth test flight because of an avionics malfunction involving the global positioning system (GPS) prior to separation. However, before returning to Mojave, test pilot Mike Melvill completed some systems testing. Mojave Aerospace Ventures LLC, photograph by David M. Moore

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On this day, the 47th anniversary of Sputnik, Brian Binnie was selected to pilot SpaceShipOne for the second of the two flights required to win the Ansari X Prize. Melvill, who had been a backbone of the program, had paved the way for Binnie only five days earlier. Melvill would now be there flying White Knight along with Matt Stinemetze as flight engineer.

Gone.

Flight Test Log Excerpt for 17P

Date: 4 October 2004

Flight Number Pilot/Flight Engineer

SpaceShipOne 17P Brian Binnie

White Knight 66L Mike Melvill/Matt Stinemetze

Objective: Second X Prize flight: again ballasted for 3 place and 100 kilometer goal (328,000 ft). (We also really wanted to break the X-15 354 kft [thousand feet] record.)

(source: Mojave Aerospace Ventures LLC, provided courtesy of Scaled Composites)

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“He dropped me, and I dropped him,” Melvill said. “That was fun.”

White Knight and SpaceShipOne lifted off together at 6:49 a. m. PST on October 4, 2004, in the chill of the desert morning with the Sun rising. In an article Binnie wrote for Air <$_ Space, he echoed the thoughts of Melvill, “The program to develop and test Burt Rutan’s SpaceShipOne (SSI) had many different demands, but I can safely say the one that made the pilots uniformly uncomfortable was the hour – long wait in SSI while the White Knight carrier aircraft dragged it up to release altitude. During this time, there is little to do and the mind is somewhat free to wander.”

As the world watched, the pressure on Binnie was enormous. With the prize of $10 million on the line, Branson waiting down below poised to begin work on SpaceShipTwo, and the fact that it was ten months since the last time he flew SpaceShipOne, which resulted in a crash landing, Binnie had plenty to wrestle with inside his head. “For me personally, a problem or failure or inability to pull this off for whatever reason, the other side of that coin was a bottomless pit. It felt to me like an abyss.”

Tensions ran high on the ground, too. “I knew that if there would be any glitches, people would say that this is not ready for prime time,” Ansari said. “And it’s not ready for commercialization and all these things.”

But when it came time to launch, every trace of doubt or uncer­tainty disappeared with the first flash of the rocket engine. Binnie’s years of navy flying and skills as test pilot took control. At 7:49 a. m., an hour after takeoff, and 47,100 feet (14,360 meters), Stinemetze pulled the lever to drop SpaceShipOne.

Table 9.1 gives the transcript of the communication between Binnie and Mission Control from the moments before separation to when the feather was locked down after reentry.

“We had no reason to delay,” Binnie said. “So, as soon as I was separated, I armed and fired the rocket motor.”

Ignition occurred immediately, and off Binnie went. SpaceShipOne zoomed past White Knight close enough for Melvill and Stinemetze to hear the hybrid rocket engine, a spaceman’s version of buzzing the tower. Figure 9.10 shows SpaceShipOne beginning to make its turn toward space. After 10—12 seconds, Binnie was thinking, “Okay, I’m still alive. I’m still in the loop. I’m still managing this thing.” But as SpaceShipOne transitioned into supersonic flight, he relaxed. The hardest part was over.

“We wanted to get to the X Prize altitude and a secondary goal of trying to beat the X-15 record,” Binnie said. “So, we wanted lots of altitude. But we also wanted to exit the atmosphere without any rolls or gyrations or large body rates so that we didn’t scare off Branson and the whole SpaceShipTwo efforts. There was that dual-edge sword of precision flying on one side and performance on the other.

“We wanted to get the nose up to 60 to 70 degrees as quickly as we could, initially, a very aggressive turn,” Binnie continued. “Once we got there, we started slowing down the pitch rate on the vehicle so that we went from 60 degrees to about 80 to 82 degrees over the next 50 seconds or so. The bulk of the flight was just milking the nose between those pitch attitudes. And then the last 20 to 25 seconds was the start of a pull again to get to about 87 to 88 degrees nose up.”

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Fig. 9.10. Brian Binnie faced the toughest flight of his entire life on October 4, 2004. He hadn’t flown SpaceShipOne since the crash landing. Now he was behind the controls of SpaceShipOne while the world’s eyes watched his every move. Mojave Aerospace Ventures LLC, video capture provided courtesy of Discovery Channel and Vulcan Productions, Inc.

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The exhaust from SpaceShipOne s rocket engine streaking upward as the contrail from White Knight veers off to the left can be seen in figure 9.11.

Binnie continued, “The initial pitch attitude to 60 to 65 degrees meant you were going to take advantage of all that rocket motor energy that is available to you and convert that to altitude. And the pull-in endgame meant you were keeping angle of attack on the vehicle and making it less susceptible to rocket-motor asymmetry in the thin upper atmosphere, where you have a delicate balance between controlling those asymmetries with little aerodynamic control power to resist it.”

After 84 seconds, Binnie shut down the rocket engine when SpaceShipOne had reached 213,000 feet (64,920 meters), zipping upward as fast as Mach 3.09 (2,186 miles per hour or 3,518 kilometers per hour). Like a pot of gold at the end of a rainbow, $10 million waited at the other end of the ballistic arc.

“I went scooting right through the X Prize altitude and past the X -15 old record by 13,000 feet [3,960 meters] or so. I got to the point after rocket motor shutdown and the feather coming up, and I hadn’t touched any of the reaction control system yet to control body rates. The vehicle was just absolutely stable. I actually used reaction control to give myself a different view so I could take some pictures.”

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Fig. 9.11. The contrail of SpaceShipOne streaks spaceward as the contrail of White Knight peels off to the left. Brian Binnie fired the rocket engine for 84 seconds, shutting it down at 213,000 feet (64,920 meters). Dan Linehan

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Fig. 9.12. Well past the boundary of space, Brian Binnie had entered the black sky. SpaceShipOne coasted to an apogee of 367,500 feet (112,000 meters), surpassing the X-15 altitude record of 354,200 feet (108,000 meters). Mojave Aerospace Ventures LLC, photograph by Scaled Composites

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Binnie reached an apogee of 367,500 feet (112,000 meters), which exceeded the Ansari X Prize requirements by nearly 7.5 miles (12 kilometers), and experienced weightlessness for more than 3.5 minutes. Binnie had a little time to take pictures, and figure 9.12 shows one of his photographs. In addition to taking photos, as figure 9.13 shows, he had the chance to do some zero-g testing on a miniature SpaceShipOne. Binnie did not release M&Ms in space as did Melvill, and it’s still unconfirmed whether Binnie ate his allotment during the captive-carry phase. Doug Shane would not speculate on the origin of several faint crackling sounds heard over the Mission Control radio.

Although weightless at apogee, SpaceShipOne had not truly escaped Earth’s pull. SpaceShipOne started to freefall and began to
accelerate, reaching Mach 3.25, which was the fastest speed it had ever reached on any of the flights. As SpaceShipOne descended into the thick atmosphere, air friction now decelerated it, and at 105,000 feet (32,000 meters), Binnie faced a peak force of 5.4 g’s pushing against his body.

As the g-forces subsided and SpaceShipOne slowed down below the speed of sound, Binnie retracted the feather at an altitude of 51,000 feet (15,540 meters). The video frames, at two-second intervals, in figure 9.14 show the transition of the feather mechanism from the extended position to the retracted position. After reentry into Earth’s atmosphere, the feather had done its job. The pair of pneumatic actuators, which can be seen connecting either side of the fuselage to the trailing edge of the

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Fig. 9.13. Brian Binnie’s trajectory was spot-on during the ascent. The hard part was over, now that gravity had taken over control of the trajectory. Binnie had 3.5 minutes of weightlessness to savor. He snapped photos and sailed a SpaceShipOne model back and forth across the cockpit. Mojave Aerospace Ventures LLC, video capture provided courtesy of Discovery Channel and Vulcan Productions, Inc.

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wings, pulled downward. This caused the feather to retract, making SpaceShipOne streamlined once more and readying it for the glide back to Mojave.

SpaceShipOne, now configured as a glider, drifted homeward. Figure 9.15 shows Sir Richard Branson, Paul Allen, and Burt Rutan spotting SpaceShipOne in the sky above Mojave.

The world watched SpaceShipOne gliding down for 18 minutes.

“I don’t know,” Ansari said, “maybe naively, I just felt that there was no more danger and everything would be fine or if there were any glitches or problems, they would be very much manageable. I wasn’t too worried because I had watched landings of SpaceShipOne a few times before.”

After only 24 minutes from being dropped by White Knight, SpaceShipOne’s wheels hit the runway for a perfect landing, as shown in figure 9.16.

“Oh, it was absolutely wonderful,” said the 434th human to reach space, summing up his spaceflight.

Once the nose skid brought SpaceShipOne to a stop and the door popped open, Binnie was instantly welcomed back by his wife as Rutan, Allen, and Branson congratulated him on the victorious flight. Towed by a pickup truck, SpaceShipOne paraded up and down the flightline in front of the thousands and thousands of cheering supporters as Binnie stood triumphantly atop, as shown in figure 9.17.

“The whole experience was very emotional for me,” Ansari said. “Even though I had nothing to do with the design and the hard work that the engineers and the team had put into building SpaceShipOne, I just felt like part of the team. I was just so proud and happy that they were successful, and that was the greatest joy to see that happen.”

Eight years after it was announced, the Ansari X Prize was finally captured, just like the Orteig Prize, first offered in 1919 and claimed in 1927. The difference was that aviation would not just take a giant leap into the air but would leap past where the air was thin to the beginning of space.

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Fig. 9.14. As SpaceShipOne fell back to Earth, the feather eased it into the atmosphere. At 51,000 feet (15,540 meters), Binnie retracted the feather, as shown by the sequence given at two-second intervals. Mojave Aerospace Ventures LLC, video captures provided courtesy of Discovery Channel and Vulcan Productions, Inc.

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Fig. 9.15. Sir Richard Branson, Burt Rutan, and Paul Allen (left to right), search the sky and spot SpaceShipOne as it nears the end of its 24-minute journey up and down from space. X PRIZE Foundation

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Fig. 9.16. Brian Binnie finished his flawless performance by making a perfect landing. After about a year and a half of flight testing, seventeen flights altogether, SpaceShipOne touched down on the runway for the last time. Mojave Aerospace Ventures LLC, video capture provided courtesy of Discovery Channel and Vulcan Productions, Inc.

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Fig. 9.17. In a matter of days, not weeks, SpaceShipOne made two spaceflights. No other vehicle in the history of space travel had accomplished this feat. Brian Binnie’s performance not only restored his confidence in himself but made it clear to the world that the future of space travel was happening right here, right now. X PRIZE Foundation

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Fig. 9.18. SpaceShipOne had done it. Eight years after its announcement by Peter Diamandis and the X Prize Foundation,

Brian Binnie had captured the Ansari X Prize. Burt Rutan, Paul Allen, and the rest of their team had pulled off the seemingly impossible.

Now was the time to celebrate the historic accomplishment and also to revel in the wonderment as the door to space flung wide open.

X PRIZE Foundation

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Table 9.1 Transcript of SpaceShipOne’s Ansari X Prize-Winning Spaceflight

This transcript was prepared using video filmed during the second Ansari X Prize spaceflight attempt from inside the cockpits of SpaceShipOne and White Knight and from inside Mission Control. The spaceflight was called X2 because it was the second attempt required by the Ansari X Prize and also called 17P because this rocket-powered flight was the seventeenth time SpaceShipOne flew. White Knight lifted off with SpaceShipOne from Mojave’s Runway 30 at 6:49 a. m. PST on October 4, 2004. The entire spaceflight lasted 1.6 hours (wheels up to wheels down for White Knight). The time stamps are hours:minutes:seconds a. m., PST. The transcript runs from just before SpaceShipOne is dropped from White Knight to just past feather retraction and lock after reentry. Acronyms used are:

AFFTC: Air Force Flight Test Center at Edwards Air Force Base

AST: Federal Aviation Administration Office of Commercial Space Transportation

BB: Brian Binnie in SpaceShipOne

BR: Burt Rutan in Mission Control

DS: Doug Shane in Mission Control

MC: Staff in Mission Control

MM: Mike Melvill in White Knight

MS: Marc de van der Schueren in the Alpha Jet chase plane

SS1: SpaceShipOne

SpaceShipOne’s journey had not ended with the Ansari X Prize, although the mission and the destination had substantially changed. SpaceShipOne was about to embark on two of its longest flights ever, one across the United States and one across the Solar System. Tyson V. Rininger

After a glide test, a rocket-powered flight, or a trip to space, SpaceShipOne made a horizontal landing on a runway like most other aircraft. As SpaceShipOne got ready to land, the pilot pneumatically actuated the nose skid and rear landing gear, as shown in figure 4.17.

A spring and gravity extended the nose skid into position. It had a maple wood tip that helped slow down the aircraft during landing. This unusual piece of landing gear also acted as a crush damper. Its simple design dramatically reduced the weight and complexity that is typical of retractable nose wheels.

The rear landing gear was also spring and gravity driven but had independent hydraulic brakes for each wheel. By fully depressing a rudder pedal, the brake engaged for the wheel on the corresponding side.

The aircraft was not equipped to retract the landing gear on its own. So, once the pilot put the landing gear down, the only way to get it back up was to land and let the ground crew reset it. There was a big, removable panel on SpaceShipOne’s belly where the rear landing gear is located that also provided access for ground support.

After resolving the avionics malfunction that caused the aborted glide flight, SpaceShipOne and White Knight were back up flying again the very same day. Melvill was dropped at 48,200 feet (14,690 meters) from White Knight flying at a speed of 105 knots. For his first maneuver, he put SpaceShipOne into a full stall to investigate stall characteristics.

The second maneuver was one of the most critical firsts of the entire flight test program. Evaluation of the feather would begin on this flight. The purpose of the feather was to decelerate SpaceShipOne during reentry into the atmosphere.

“That’s something you do in glide tests,” Burt Rutan said. “You don’t have to do that in spaceflight because once you decelerate from your spaceflight, you find yourself in a stable glide, which is identical to the way we flew the airplane on its first glide flight. So, we went out early in the program and put the feather up and put it down.”

Rutan had planned to do a high-speed pull-up in a glide flight and put the feather up as it peaked to simulate zero-g during the beginning of the program. But this turned out unnecessary and would have used up too much altitude. “We started off at 43,000 feet [13,110 meters] and put the feather up to make sure it flew the way we wanted,” Doug Shane said. “We ended up doing feather

Flight Test Log Excerpt for 5G

Date: 27 August 2003

Flight Number Pilot/Flight Engineer

SpaceShipOne 5G Mike Melvill

White Knight 32L Brian Binnie/Cory Bird

Objective: Same objectives as the aborted flight 31LC/4GC earlier today. Second glide flight of SpaceShipOne. Flying qualities and performance in the spaceship reentry or "feather" mode. Pilot workload and situational awareness while transitioning and handling qualities assessment when reconfigured. As a glider, stall investigation both at high and low altitude and envelope expansion out to 200 knots and 4 g’s. More aggressive, lateral directional characteristics including adverse yaw, roll rate effectiveness and control, including 360 degrees aileron roll, and full rudder side slips.

(source: Mojave Aerospace Ventures LLC, provided courtesy of Scaled Composites)

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deployments from tail-slide entries, and it just worked great. Everything was as good as we could have possibly hoped for.”

SpaceShipOne was gliding along at an airspeed of 90 knots when Melvill unlocked and activated the feather. As the tail booms began to elevate to their fully extended position of 65 degrees, the nose of SpaceShipOne pitched up but settled back to a near-level pitch. Melvill encountered a lot of buzzing and buffeting during the 70-second feathered descent.

With the feather deployed, SpaceShipOne dropped at a rate greater than 10,000 feet per minute [3,050 meters per minute]. However, it was extremely stable as it fell to the ground belly first.

“You could change the heading,” Mike Melvill said. “If you were pointing at Cal City, you could turn around and point it to Mojave. And you used the elevons to do that. It was kind of weird because normally it would roll, but your sensation was that it was yawing.”

“If you stepped on the rudders, it wasn’t perceptible to you what was happening. Nothing happened. The only thing that really did anything was lateral spin. It was kind of neat to go over and look at a different view, and look over there and see what was over there. We did that a lot when we were flying as a glider in the atmosphere.”

At 30,000 feet (9,140 meters) Melvill retracted and locked down the feather. SpaceShipOne was back as a glider, as shown in figure 7.6. He expanded the flight envelope for airspeed and g-force. And before landing, he executed SpaceShipOne’s first roll.

n November 6, 2004, the X Prize Foundation presented the Ansari X Prize trophy and the $10 million. Figure 10.1 shows Burt Rutan, Paul Allen, Mike Melvill, and Brian Binnie with members of the X Prize Foundation, Peter Diamandis, Gregg Maryniak, Amir Ansari, and Bob Weiss holding up the prize money. In order to also join in the celebration, Allen had flown the entire Scaled Composites team in one of his private airliners to the award ceremony held in St. Louis. Figure 10.2 shows the Scaled Composites team from an earlier photograph.

SpaceShipOne and the Ansari X Prize began on two separate but parallel courses. When they converged, their combined importance was greater than the sum of the two parts. It is difficult to imagine what the result would have been if SpaceShipOne or the Ansari X Prize had been taken out of the equation. Would another team have won the Ansari X Prize with the deadline and the funding set to expire in just a few months? Would the general public have had the awareness or been as involved to the degree that it was without the Ansari X Prize? Without the space mania would investors like Sir Richard Branson have embraced Rutan with such a sizable financial commitment?

The years 1996 to 2004 were very much a different time compared to the years 1919 to 1927. And although the Ansari X Prize was modeled after the Orteig Prize, it certainly was not a one-to-one substitution. At the end of the day, the X Prize Foundation did what they had to do to realize their dream. At the end of the day, Scaled Composites did what they had to do to realize theirs.

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Fig. 10.1. The Ansari X Prize trophy and $10 million check were presented on November 6, 2004, to Mojave Aerospace Ventures, the official partnership between Paul Allen’s Vulcan and Burt Rutan’s Scaled Composites. The photograph shows Bob Weiss, Gregg Maryniak, Amir Ansari, Peter Diamandis, Brian Binnie, Mike Melvill, Burt Rutan, and Paul Allen (left to right) at the award ceremony hosted in St. Louis. Mojave Aerospace Ventures LLC, photograph by Scaled Composite

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Fig. 10.2. In the Mojave Desert, which is referred to as the birthplace of the sonic boom, Scaled Composites, a small company founded by Burt Rutan in 1982, grew from an innovator in aircraft to an innovator in spacecraft. Without the efforts of the whole team, SpaceShipOne would never have been able to burst through Earth’s atmosphere and truly become a spaceship. Mojave Aerospace Ventures LLC, photograph by Scaled Composites

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Fig. 10.3. Influenced by the success of the Ansari X Prize, NASA announced the Centennial Challenges in 2005. John Carmack’s Armadillo Aerospace, an Ansari X Prize competitor, just missed winning the Lunar Lander Challenge in 2006. The lander, shown here, demonstrated vertical takeoff, hover, horizontal translation, and vertical descent, but it couldn’t stick the landing in the end. Dan Linehan

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It is safe to say that those who have dreamed of someday flying into space had their chances become much, much better because of Rutan and the Ansari X Prize, whether it be on a ride in SpaceShipTwo with Virgin Galactic or in another suborbital spacecraft from a different spaceline.

One of the more distinguishing features of SpaceShipOne is its windshield, made of sixteen 9-inch- (23-centimeter-) diameter windows. The windows are small and round to keep the weight low and the structural strength high. Good visibility for the pilot flying SpaceShipOne, during all phases of the mission, was an important design consideration. This determined the arrangement of the windows.

With a slight tilt of the head, the pilot could always keep the horizon in sight. For one of SpaceShipOne’s rocket-powered flights, this proved crucial when the avionics display went temporarily blank. However, similar to the Spirit of St. Louis, the windows do not allow the pilot to see directly ahead of the spacecraft during landing.

Each window has dual panes and dual seals. This redundancy helped prevent loss of cabin pressurization in the case of damage to a window. The outer panes are 5/16-inch – (0.79-centimeter-) thick, heat-resistant Lexan polycarbonate. They are separated by a 1 /4-inch (0.64-centimeter) gap from 5/16-inch – (0.79-centimeter-) thick Plexiglas inner panes. There are small vent holes in the outer panes to help prevent the window from fogging up. The inner panes took all the pressurization and when loaded, could deflect 0.2 inches (0.5 centime­ters). Even if the inner panes failed, the leak rate would be very low, and SpaceShipOne could easily glide back home. Airliner windows also commonly use a two-pane construction with vent holes.

The crew entered SpaceShipOne through a 26-inch – (66-centimeter-) diameter, dual-sealed plug door on the port side. The door does not have an external handle but does have an internal handle that the crew could grab and pull out. Just like the plugs on the sides of the cockpit, it is shaped so that the pressure inside the spaceship held the door in place.

The spacecraft was not designed to have ejection seats, in order to help keep the cost, weight, and complexity at a minimum.

The nose cone was an escape hatch. Once it was unlocked, the pilot uses a handle near his left foot to turn the nose cone on its gear ring. After a clockwise turn of only 7.5 degrees, the nose cone detached and fell free from SpaceShipOne. Figure 4.18 and figure 4.19 both show views after the nose cone was detached. During an emergency egress, the

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Fig. 4.18. A 36-inch (91-centimeter) opening reveals the cockpit after the nose cone twists off. The crew could use this opening or the 26-inch- (66- centimeter-) diameter plug-style door on the left side of the cockpit for emergency egress if necessary. Mojave Aerospace Ventures LLC, photograph by

David M. Moore

rudder pedals as well as most of the instruments are dragged out of the cabin by the nose cone, clearing a 36-inch – (91-centimeter-) diameter opening for the crew to crawl through. The crew then would have parachuted to safety after clearing SpaceShipOne.

The focus of the test flight program now began to shift to prepare for the upcoming rocket-powered flights. Up to this point, SpaceShipOne was flown light, but for rocket-powered flight, it would have to maneuver with a fully fueled rocket engine. SpaceShipOne was loaded so the center of gravity (CG), or the single balance point of SpaceShipOne s mass, moved to the aft to simulate these conditions.

When Melvill tested the stall characteristics for the aft-loaded SpaceShipOne, the nose swung upward uncontrollably before the wings reached the angle of attack at which they were expected to stall. SpaceShipOne entered into a spin while Melvill fought to regain control. Figure 7.7 shows SpaceShipOne as Melvill recovered from the tail stall.

“We had a pretty significant departure from controlled flight at high angle of attack, aft CG, due to a tail stall. That really was a big surprise,” Doug Shane said.

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Flight Test Log Excerpt for 6G

Date: 23 September 2003

Flight Number Pilot/Flight Engineer

SpaceShipOne 6G Mike Melvill

White Knight 37L Pete Siebold/Matt Stinemetze

and Jeff Johnson

Objective: Third glide flight of SpaceShipOne. Aft CG flying qualities and performance evaluation of the spaceship in both the glide and reentry or "feather" mode. Glide envelope expansion to 95 percent airspeed, 100 percent alpha [angle of attack] and beta [sideslip angle], and 70 percent load factor. More aggressive post-stall maneuvering and spin control as a glider and while feathered. Nitrous temperature control during climb to altitude and performance of upgraded landing gear extension mechanism and space-worthy gear doors.

(source: Mojave Aerospace Ventures LLC, provided courtesy of Scaled Composites)

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Fig. 7.6. After quickly correcting the avionics malfunction, SpaceShipOne and White Knight returned to the air several hours after the aborted fourth test flight.

During this flight test, SpaceShipOne extended its feather for the first time. It performed superbly. Mojave Aerospace Ventures LLC, photograph by David M. Moore

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Fig. 7.7. The sixth glide flight, on September 23, 2003, focused on the handling qualities when SpaceShipOne was loaded in the back, where the heavy rocket engine would eventually be. SpaceShipOne stalled unexpectedly, and the photograph shows the craft right after recovery.

Mojave Aerospace Ventures LLC, video capture provided courtesy of Discovery Channel and Vulcan Productions, Inc.

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The feather wasn’t raised during the test flight, but during the climb to release altitude, the pressure test of the oxidizer tank revealed a variation of less than 6 psi. This meant that the temperature of the nitrous oxide inside could be controlled very well by exhaust air ducted in from White Knight.

Scaled Composites needed wind-tunnel data to evaluate the problem with the tail booms. “Except we didn’t have a wind tunnel, but we did have a pickup truck. And we had our aero guy, Jim,” Shane said.

Using a converted pickup truck fitted up with instrumentation, called the Land Shark, engineers aerodynamically tested mockups of the tail boom. With clearance from Mojave Airport, the Land Shark zoomed up and down a runway to collect data.

“We finally ended up doing a fence and a span increase on both the stabilizer and the elevon and resolved the problem,” Shane said.

A triangular strake was also added to each tail boom, right in front of each horizontal stabilizer. SpaceShipOne was ready to go back to flight testing.

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Flight Test Log Excerpt for 7G

Date: 17 October 2003

Flight Number Pilot/Flight Engineer

SpaceShipOne 7G Mike Melvill

White Knight 38L Pete Siebold/Cory Bird

and David Moore

Objective: Fourth glide flight of SpaceShipOne. Primary purpose was to examine the effects of horizontal tail modifications at both forward and mid-range CG locations (obtained by dumping water from an aft ballast tank between test points). The tail modifications included a fixed strake bonded to the tail boom in front of the stabilator and a span-wise flow fence mounted on the leading edge of each stab at mid-span. Other test objectives included a functional check of the rocket motor controller, ARM,

FIRE, and safing switches as well as the oxidizer dump valve. Additional planned maneuvers included full rudder pedal sideslips and more aggressive nose pointing while in the feathered configuration.

(source: Mojave Aerospace Ventures LLC, provided courtesy of Scaled Composites)

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As the involvement and development of the commercial space indus­try continues to move forward and expand, many new ideas and designs are being introduced to the public. Even NASA has gotten into the spirit of public and commercial spaceflight. In 2005, the agency announced the first two cash prizes in a series called Centennial Challenges: the space tether and beam-power challenges,
which are both the components needed to build an elevator to space. In 2006, the less obscure lunar lander challenge was added, and other challenges soon followed.

NASA has partnered with the X Prize Foundation to run some of the Centennial Challenges during the annual X Prize Cup. Figure 10.3 shows the lunar lander of John Carmack’s Armadillo Aerospace, a team that had competed for the Ansari X Prize, whose amazing demonstration missed winning the challenge in 2006 by the slimmest of margins.

The X Prize Cups are a cross between air shows and space expos, where companies show off and, in some cases, even demonstrate many of the latest and greatest ideas. One of the big attractions is the Rocket Racing League, which is still in development.

Sean D. Tucker, a champion aerobatic pilot who is looking forward to flying in the league, said, “It is going to be very similar to a Red Bull course except longer and higher, and I think there are going to be milestones in the sky and altitudes you have to hit in the sky as well and then come back down. I think it is going to be a truly three-dimensional course, They’re working with the technology now to have heads-up displays where you can see the virtual course in the air.” Figure 10.4 shows a prototype rocket racer.

As recently as 2001, Dennis Tito became the first paying space tourist, flying to the International Space Station aboard a Russian Soyuz. Since then, four others have made this $20 million, or more, journey. In 2006, Anousheh Ansari was doing research based upon
this type of spaceflight for a venture she was involved with. She said, “I was looking into it to find out what type of training was really required if we were to commercialize orbital flights. Do people real­ly need six months of training and all these things? The best way to find out was to go through the program. I started training as a back­up. But three weeks before the flight the primary crewmember got ill. He failed one of his medical tests. And that’s when they said, ‘Well, if you want to go, you can go. You can take that seat now.’ And I just couldn’t say no to that.”

Figure 10.5 shows Ansari floating about in the International Space Station. She skipped over suborbital entirely and went straight to orbital. With Ansari’s support, she helped open the door to space a

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Fig. 10.5. Space tourism began in 2001 when Dennis Tito rocketed to the International Space Station in a Russian Soyuz. In 2006, Anousheh Ansari joined the handful of people who have made this same journey. At between $20 million and $40 million, this ticket is out of reach from most people.

But a growing number of entrepreneurs are recognizing that there is not just a desire for space but a demand for space. Prodea Systems, Inc. All rights reserved. Used under permission of Prodea Systems, Inc.

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little wider for the rest of the public. This unexpected opportunity for her was well deserved.

One of the bigger prizes still out there is the $50 million America’s Space Prize announced in 2004 by Bigelow Aerospace, which is an orbital version of the Ansari X Prize. In 2007, the X Prize Foundation raised the ante, not in terms of money but in terms of miles. Partnering with Google, the $30 million Google Lunar X Prize will have teams compete to land on the Moon. This is a
one-way ride, though. No self-replicating, carbon-based life forms are required for the trek. But before orbital or lunar spaceflights get going for the public, there is still another race on for suborbital flights. About a dozen companies are currently developing suborbital spacecraft, several of which were Ansari X Prize competitors, like Starchaser and the da Vinci Project. The truth is, there is an enormous amount of activity behind the scenes as well as on center stage.

Because SpaceShipOne slowed down so quickly, it did not experience extreme temperatures very long. Therefore, thermal loads were much smaller than those faced by the Space Shuttle. SpaceShipOne required only a relatively simple thermal protection system (TPS). Its TPS design consisted of two main parts.

The first part was built in during the manufacture of the composites. When the composite skins for the areas that would experience high temperatures during reentry were constructed, instead of

epoxy, a phenolic resin was used with the carbon fiber. The temperature tolerance for these composites increased by 50 to 70 degrees Fahrenheit.

About 14 pounds (6.4 kilograms) of an approximately 0.035-inch – (0.09-centimeter-) thick ablative coating developed by Scaled Composites was added to 25 percent of the surface of SpaceShipOne as the second part of the TPS. Ablative coatings made of reinforced plastic have been around since the early space program. The ablative process reduces the temperature of a spacecraft’s surface that faces the airstream on reentry by absorbing some of the heat that is generated. The heat absorbed causes the ablative coating to burn free of the spacecraft, so, in effect, the coating carries away a portion of the heat when it flies off the spacecraft.

When the ablative coating burns, it undergoes a chemical reaction. The heat provides the energy needed for this chemical reaction to

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Fig. 4.20. Wax stripes were added to the various surfaces exposed to heating during reentry. These surfaces already had a red-colored coating that was part of the thermal protection system (TPS). Each colored wax stripe on the right wingtip, as shown here, melted at a different temperature. By studying the remaining wax after a flight, engineers could determine a heating profile. Mojave Aerospace Ventures LLC, photograph by David M. Moore

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occur. Therefore, the heat absorbed during the ablation process is heat that is no longer available to heat up SpaceShipOne. The abla­tive coating is then reapplied for the next spaceflight. Figure 4.20 shows the temperature effects on a wingtip and its colored wax test stripes.

Even in the worst-case scenario where the TPS was completely gone, the fuselage could have withstood the damage and returned the crew unharmed. Because of the short duration and relatively low altitude of the spaceflight, SpaceShipOne was not equipped with radiation shielding.