Category Space Ship One

X1: The First Ansari X Prize Flight (16P)

“Ladies and gentlemen, we are at the start of the personal spaceflight revolution, right here, right now. It begins in Mojave, today. What is happening here in Mojave today is not about technology. It is about a willingness to take risk, to dream, and possibly to fail,” said Peter Diamandis during the morning of September 29, 2004, as XI, the name of the first required flight of SpaceShipOne in the quest for the Ansari X Prize, prepared to launch.

Mojave was abuzz. A little more than three months earlier, Mike Melvill had earned his astronaut wings as he piloted SpaceShipOne on a history-making flight just past the 100- kilometer (62.1 miles or 328,000 feet) line demarking the start of space. Now Rutan’s team set their sights on the most exciting and influential prize of the new millennium.

Pete Siebold, who had already flown two glide flights and one powered fight in SpaceShipOne, was selected to pilot the flight. Siebold had been training for three years for this moment, but a health scare forced a very disappointing change.

“There were two other guys that were more than qualified to fly that flight,” Siebold said. “At the time, I didn’t feel as though I was doing the team any justice by putting myself in that situation and flying
the mission when I probably wasn’t in the right frame of mind and not to mention healthy enough.” Siebold made the tough decision, but very fortunately his health issues were eventually determined to be nowhere near as serious as first suspected.

Rutan then turned to the test pilot with the most experience flying SpaceShipOne. Mike Melvill would get his chance to become an astronaut a second time, but to do so, he’d have to get back into training again. Figure 9.3 shows Melvill at the controls in the cockpit of SpaceShipOne preparing for XI.

Like Spirit of St. Louis, SpaceShipOne was stripped of anything absolutely nonessential. The lighter the craft, the greater the margin SpaceShipOne had for clearing the 100 kilometers (62.1 miles or 328,000 feet) because the removal of each and every pound enabled the spacecraft to go an additional 150 feet (46 meters) higher. SpaceShipOne needed all the help it could get. Melvill’s earlier spaceflight had cleared the 100 kilometers by only the slimmest of
margins, less than 500 feet (150 meters). And during this spaceflight, SpaceShipOne was not even carrying the full payload required by the rules of the Ansari X Prize.

Ironically, as the Scaled Composites team scrimped for a pound here and a pound there, removing a total of about 45 pounds (20 kilograms), they would have to add weight to simulate two passen­gers. “We had to carry 400 pounds [180 kilograms] in the back seat, which was a heck of a lot more load in that thing than we ever had before. And I had to be ballasted,” Melvill said.

Since Melvill weighed only 160 pounds (73 kilograms), he had to be ballasted up to 200 pounds (90 kilograms).These were the rules. But keeping the gross weight as low as possible was still critical. Every pound that didn’t have to be carried was a pound that the force from the rocket engine didn’t have to lift.

Figure 9.4 shows Melvill gesturing “okay” from a removable port as final preparations were made. SpaceShipOne was carried

X1: The First Ansari X Prize Flight (16P)

X1: The First Ansari X Prize Flight (16P)

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Fig. 9.4. Mike Melvill gives the thumbs up from the cockpit of SpaceShipOne as last-minute preparations are made. For the Ansari X Prize,

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SpaceShipOne had to carry enough weight to simulate three 198-pound (90-kilogram) people. SpaceShipOne just barely made it past 328,000 feet (100,000 meters) without the extra weight, so it was necessary to bump up the performance of the rocket engine. Mojave Aerospace Ventures LLC, photograph by David M. Moore

into the air at 7:12 a. m. PST by White Knight with Brian Binnie behind the controls.

Separation occurred at 8:10 a. m. PST when flight engineer Matt Stinemetze, who sat in the back seat of White Knight, released SpaceShipOne from an altitude of 46,500 feet (14,170 meters). Clear of White Knight and no longer pushing forward on the control stick, Melvill fired the rocket engine, which had been enhanced to provide greater performance by increasing the amount of propellant and burn time.

“You could sure hear it,” Melvill said. “It was very loud—it was extremely loud.

“But it is a fabulous ride going up. I think that people who go on the next one—the passengers—will get the most exciting thing they ever did. A lot of noise. They are going really fast. The acceleration is dramatic. You are accelerating at a huge rate. You just watch the speed going up.”

The cockpit shook as Melvill pulled the nose up, making a very sharp turn toward the sky above. “The straighter you flew it, the

X1: The First Ansari X Prize Flight (16P)

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Fig. 9.5. A video-capture image shot from a chase plane shows SpaceShipOne spiraling up during its boost. Melvill struggled to control the rolls but still allowed SpaceShipOne’s rocket engine to fire so he would be sure to pass the 328,000-foot (100,000-meter) mark. SpaceShipOne rolled twenty-nine times. Mojave Aerospace Ventures LLC, video capture provided courtesy of Discovery Channel and Vulcan Productions, Inc.

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higher it would go in the same amount of time,” he said. “We didn’t need to burn the motor for its full length that it was capable of burning because it went up there quite easily.”

During his previous flight, though, he had battled wind shear, rocket asymmetries, and pitch control failure. These had prevented him from flying a very straight trajectory. Melvill was more than determined to nail the trajectory on this flight.

As SpaceShipOne blasted through the upper atmosphere, Melvill had closed up the two donuts on theTONU display, which meant he was doing a great job flying the planned trajectory, and he monitored the energy altitude predictor, an instrument that predicted how high SpaceShipOne would go once the rocket engine was shut down.

“You may be at 160,000 feet [48,770 meters],” Melvill said, “and it will say, if you turn it off right now, you’ll go all the way to 328,000 feet [100,000 kilometers]. So, you watch that instrument. That’s the primary instrument to know when to turn it off. Initially, we did it with a timer, and we just said you’re going to run 55 seconds. And at the end of 55 seconds, we’d shut it off.”

But only 60 seconds after lighting the rocket engine, traveling at Mach 2.7, SpaceShipOne was in trouble. The crowd hushed as the contrail from SpaceShipOne switched from a nice, smooth line to a wild corkscrew in the sky. Things happened fast. But from the angle of the shot displayed on the jumbo screen, it was hard to tell what was actually happening. Figure 9.5 shows SpaceShipOne rolling out of control, viewed from the cockpit of a chase plane.

“When he started doing the rolls, I thought he was dead,” recalled Erik Lindbergh. “I thought that was it—the craft was going to break up and he was done.”

Thousands of people were gripped in silence.

“I didn’t think he was doing rolls. I thought he was tumbling at that point,” Lindbergh recalled.

SpaceShipOne rolled right uncontrollably at an initial rate of 190 degrees per second, spiraling up toward space.

“I had one of the walkie-talkies, and I could hear Melvill talking to ground control,” Ansari said. “He said that everything is fine. It didn’t look fine. But because he was convinced that everything was fine, I felt comfortable.”

The rocket engine kept burning while SpaceShipOne still spun its way up, reaching a maximum speed of Mach 2.92 (2,110 miles per hour or 3,400 kilometers per hour). Melvill still kept his eye on the energy altitude predictor. As he explained, “Unless you see 328,000 feet [100,000 meters] in that window, you are not going to win the X Prize. So, you don’t want to turn it off until you read at least that much or more. And so that was why I didn’t turn it off when we were doing all those rolls, because it didn’t say 328,000 feet [100,000 meters] yet. I went to turn it off thinking, wow, something was wrong here. And when I looked at the energy height predictor, it was not predicting that we would go high enough. So, I just left the motor running and just ignored the rolling.”

At a total burn time of 77 seconds, Melvill finally shut off the rocket engine. His altitude was 180,000 feet (54,860 meters) at that point and only about halfway through its ascent. But as Melvill got higher and higher, the air became too thin for him to counteract the rolls with either the subsonic or supersonic flight controls. SpaceShipOne left the atmosphere still rolling at 140 degrees per second.

Melvill was able to keep from being disoriented by focusing on the Tier One navigation unit and not glancing out the windows. He acti­vated the feather and then focused on nulling-out the rolls with the reaction control system. “I just pushed it on, turned on both systems, and just left it on until it stopped it,” Melvill said.

By the time SpaceShipOne stopped rolling, it had completed twenty – nine rolls. The vehicle now continued to coast to an apogee of 337,700 feet (102,900 meters), but now Melvill could enjoy the 3.5 minutes of weightlessness and the view while still having time to take a few photos out the window.

On reentry, SpaceShipOne hit a top speed of Mach 3.0. Still in the feathered configuration, it decelerated from supersonic to subsonic,

X1: The First Ansari X Prize Flight (16P)

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Fig. 9.6. By using the reaction control system (RCS), Mike Melvill stopped the rolls. He reached an apogee of 337,700 feet (102,900 meters), which gave him about 10,000 feet (3,000 meters) to spare.

Now, coming down was the easy part. Mojave Aerospace Ventures LLC, video capture provided courtesy of Discovery Channel and Vulcan Productions, Inc.

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X1: The First Ansari X Prize Flight (16P)л

Fig. 9.7. SpaceShipOne’s second spaceflight was nearly over as it approached Mojave’s runway. But before Melvill had gotten close to the airport, he did some early celebrating by rolling SpaceShipOne once more to make it an even thirty. Mojave Aerospace Ventures LLC, video capture provided courtesy of Discovery Channel and Vulcan Productions, Inc.

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X1: The First Ansari X Prize Flight (16P)

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X1: The First Ansari X Prize Flight (16P)

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Fig. 9.9. On October 4, 1957, Sputnik became the first man-made object to orbit Earth. The Soviet Union had launched the beach ball­sized satellite, which circled the planet for three months. Sputnik put the space race between the United States and Soviet Union into overdrive. Decades later, on this day, SpaceShipOne was ready to finish a race of its own. NASA

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while it reached a peak g-force of 5.1 g’s at 105,000 feet (32,000 meters).

At 61,000 feet (18,590 meters), Melvill retracted the feather to begin his glide back to Mojave. As SpaceShipOne descended, the chase planes caught up and tucked in behind. Figure 9.6 shows the view of SpaceShipOne from the Alpha Jet.

During the 18-minute glide to Mojave, SpaceShipOne suddenly rolled completely around, surprising the chase planes. But this roll wasn’t uncommanded. Melvill performed a victory roll, rounding out his total rolls for the flight at thirty.

Figure 9.7 shows SpaceShipOne coming in for a landing as the crowds lining the runway cheered.

“It was fabulous—it really was—knowing that we at least were halfway there. We went plenty high. And coming back and all the excitement, everybody was just thrilled to death,” Melvill said.

Melvill’s flight exceeded the altitude requirement by nearly 10,000 feet (3,050 meters) and satisfied the other rules set by the Ansari X Prize. To fulfill the remaining conditions, SpaceShipOne had to repeat the spaceflight within two weeks. Standing on SpaceShipOne, Melvill celebrated successfully completing the XI, as shown in figure 9.8.

“We knew what we had to do. My task was to not damage the air­plane. I wasn’t going to go for any altitude records but just plenty of margin and burn the engine as little as possible and land the airplane as smooth as possible so we didn’t have to fix anything. We didn’t even change the tires. We refueled it, and it was ready to go. We could have gone the next day,” Melvill said.

Supersonic Flight Control

Similar to the Bell X-l, as shown in figure 6.6, which in 1947 was the first aircraft to break the sound barrier, SpaceShipOne used elec­tric, motor-driven control surfaces to maneuver. After SpaceShipOne
broke the speed of sound during test flights, the subsonic flight con­trols no longer functioned efficiently.

“Once you are supersonic, the control system that you normally use to fly the airplane doesn’t work anymore,” Melvill said. “Because it is a mechanically controlled airplane, there is no hydraulic system like there is on an F-16 or F-l 8. It is just cables and pushrods. You are just not strong enough to move the controls at that point. So you just revert to using the trim switches.”

Supersonic Flight ControlГ"

Подпись:Fig. 6.6. Because the forces pushing against the control surfaces of the X-1 were so strong while flying at supersonic speeds, the pilot could not use conventional mechanically linked flight controls. The control surfaces had to be electrically controlled and moved using electric motors. SpaceShipOne used a similar system for flying above Mach 1. NASA-Dryden Flight Research Center

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Many aircraft have trim controls that help the pilots maintain course by slightly altering control surfaces. By changing a trim setting, a pilot can fine-tune the control surfaces, so less force has to be applied to the control stick and rudder pedals in order to stay on course. SpaceShipOne uses trim controls in a somewhat similar way during supersonic flight.

A switch on the top of the control stick activated electric servos that pivoted the entire horizontal stabilizer on each side of SpaceShipOne for pitch trim. In figure 6.7, a close-up of a tail boom shows the numeric scale that indicates the amount of deflection for the horizontal stabilizer as set by the pilot.

Supersonic Flight Control

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Fig. 6.7. Triangular strakes were added in front of the horizontal stabilizers, which were also enlarged, to improve the aerodynamics of SpaceShipOne. The numbers to the right of the strake show the amount of trim or deflection of moveable horizontal stabilizers. Mojave Aerospace Ventures LLC, photograph by David M. Moore

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A knob at the pilot’s left side called the “turtle” activated the lower half of each rudder, giving yaw trim. “Yawing the airplane caused it to roll because of the high wing and the swept leading edges,” Melvill said. “We actually didn’t use the roll trim. It was too powerful. We used yaw trim to roll the plane. If it was rolling off to the left, you would yaw it to the right.”

The lower rudders were synced and moved in the same direction, unlike the upper rudders used in subsonic flight. “The geometry is such that they go out a lot and in just a little bit,” Rutan added. “But they never work opposite.”

Trimming was also used to restrict the movement of SpaceShipOne during test flights. For example, when Mission Control monitored the trajectory of SpaceShipOne, they would instruct the pilot to make trim changes in order to help him stay on course.

More than midway through the burn, the atmosphere became so thin that the supersonic flight controls were no longer needed. The pilot was able to control SpaceShipOne with subsonic flight controls, even though it was flying much faster than the speed of sound, because the rarified air produced little opposing force. When SpaceShipOne fully left the atmosphere, the pilot then switched over to the RCS.

A New Pilot Behind the Stick (8G)

Flying at 115 knots and 47,300 feet (14,420 meters), Pete Siebold detached from White Knight. Shown at the controls of SpaceShipOne in figure 7.10, Siebold became the second test pilot to fly SpaceShipOne. Mike Melvill had flown all the previous manned test flights.

Although SpaceShipOne’s performance was really starting to become dialed in, there was no shortage of work to do. Untested controls and the modified horizontal stabilizers needed evaluation— all this while Siebold learned how SpaceShipOne flew outside of the realm of the simulator. Figure 7.11 shows small strings attached to the horizontal stabilizer. With one free end, these strings helped the engineers identify how the air flowed over its surfaces.

Before Siebold completed the glide flight, he had to work on a new landing procedure that he and Binnie had been devising in order to improve reliability. “We had both very short, almost didn’t make it to the runway, and very long, almost off the end of the runway, landing excursions,” Doug Shane said.

Although SpaceShipOne glided okay, it didn’t have anywhere near the performance or control of a sailplane effortlessly gliding upward on the tops of thermals. The procedure involved overflying the run­way and hitting altitude waypoints while being able to accommodate coming into the approach too high or too low. After 19 minutes and 55 seconds in the air, SpaceShipOne landed at the intended aim-point.

Flight Test Log Excerpt for 8G

Date: 14 November 2003

SpaceShipOne White Knight

Objective: The fifth glide flight of SpaceShipOne. New pilot checkout flight. Stability and control testing with the new extended horizontal tails. Tests included stall performance at aft limit CG and evaluation of the increased pitch and roll control authority. Other objectives included additional testing of the motor controller (MCS) and handling qualities in feathered flight.

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

A New Pilot Behind the Stick (8G)

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Fig. 7.11. During Pete Siebold’s first flight, he had to evaluate additional modifications to the horizontal

stabilizers put in place to rectify handling issues revealed two flights earlier. Small strings attached to the newly enlarged horizontal stabilizers were used to help analyze the air flow. Mojave Aerospace Ventures LLC, video capture provided courtesy of Discovery Channel and Vulcan Productions, Inc.

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A New Pilot Behind the Stick (8G)A New Pilot Behind the Stick (8G)A New Pilot Behind the Stick (8G)Fig. 7.12. Mike Melvill returned to the pilot’s seat for the ninth flight, which was the sixth glide flight of SpaceShipOne. In the photograph, Melvill pulls a handle to his left to deploy the feather for additional evaluation. Mojave Aerospace Ventures LLC, video capture provided courtesy of Discovery Channel and Vulcan Productions, Inc.

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Fig. 7.13. An abort while fully fueled was a very big concern for Scaled Composites because

of the heavy weight for landing. Even when testing SpaceShipOne’s performance with ballast to more closely match the weight of a fully fueled rocket engine, it was necessary to dump the ballast prior to landing. Mojave Aerospace Ventures LLC, video capture provided courtesy of Discovery Channel and Vulcan Productions, Inc.

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Fig. 7.14. Among the biggest surprises to Scaled Composites was the difficultly of landing SpaceShipOne without undershooting or overshooting the runway. The test pilot had to manage the airspeed and altitude very carefully on approach to the runway for landing. Mojave Aerospace Ventures LLC, video capture provided courtesy of Discovery Channel and Vulcan Productions, Inc.

A New Pilot Behind the Stick (8G)

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Flight Test Log Excerpt for 9G

Date: 19 November 2003

Flight Number Pilot/Flight Engineer

SpaceShipOne 9G Mike Melvill

White Knight 41L Brian Binnie/Cory Bird

Objective: The sixth glide flight of SpaceShipOne. Test pilot Mike Melvill’s first flight with the enlarged tails. Emergency aft CG handling qualities eval and simulated landing exercise with the new tail configuration. Airspeed and g envelope expansion and dynamic feather evaluation.

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

A New Pilot Behind the Stick (8G)

Tail Booms

All the flight control surfaces are on the tail booms, which are mounted to the wingtips and pivot with the aft wing sections when the feather is deployed. Each tail boom has a vertical stabilizer and horizontal stabilizer.

Upper and lower rudders are mounted at the back of each vertical stabilizer for yaw control. Pitch and roll is controlled by elevons that are attached to the trailing edges of the outward extending horizontal stabilizers. The fiberglass construction of the elevon skin gives radio transparency for antennas. For control during supersonic flight, the entire horizontal stabilizer on each tail boom pivots.

Подпись: ; g '1 ~ГГ * |ГШГ Подпись:Minor modifications were made to the tail booms during flight testing. To resolve an aerodynamic problem, the distance from tip to root of the horizontal stabilizers was increased by 16 inches (41 centimeters). Also, a triangular strake was added in front of each horizontal stabilizer, and a flow fence was added midspan on each horizontal stabilizer.

Tail Booms

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Fig. 4.15. Critical to the safe return from space, the feather had only two positions, all up or all down. Redundant pneumatic actuators raised and lowered the feather. While retracted, the feather was held in place by a redundant locking system. However, only the force from the pressurized

actuators was needed to keep the feather fully extended. Mojave Aerospace Ventures LLC, photograph by David M. Moore

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Tail BoomsFig. 4.16. During reentry and with the feather extended at an angle of about 65 degrees, SpaceShipOne descended nearly level on its belly. It did not drop straight down, though, but instead moved forward as it fell. The diagram shows the angle of attack at 60 degrees, which is a measure of the direction of motion with reference to the position of the wing.

James Linehan

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Turnaround Time

The twenty-nine rolls not only caused great concern for safety, but now doubt and skepticism started to creep into the back of people’s minds. One or two rolls wouldn’t have been so dramatic, and would not have left such a vivid impression. But with twenty-nine, even the most inexperienced spectator could tell things weren’t going as planned. The public had not yet bought into the whole idea of personal space travel. There was a big difference between being enthusiastic and thinking something was cool and being willing to put your own butt in the seat strapped to a rocket engine. Some people would of course be willing to take any risk to get into space. But that certainly wouldn’t be the best way to jumpstart an industry in this day and age. Sometimes perception, unfortunately, weighs heavier than fact.

“We saw this rolling departure, and that was cause for concern,” Binnie said. “Not from a safety or structural standpoint but a concern of perception. Others thought, ‘Well, they are just loose cannons out there. They don’t understand what they are doing. They are certainly not ready for prime time or carrying the trusting public.’ And so the clock is ticking.

“We had planned this to where we could potentially pull off three flights in two weeks if need be. But we were all getting kind of tired. We really didn’t want to have a problem on our second attempt. Everybody on the team was well aware of what was at stake and what would all be necessary should it have to come to a third flight. And any number of things could put us there. It could be bad weather, an avionics hiccup, range issues, telemetry things, and issues totally unrelated to flying the vehicle could have scuttled that event and forced us into a third evolution.”

The fact was that after evaluating the data from X1, the team determined Melvill had done too good of a job at pointing SpaceShipOne straight up. In this orientation, SpaceShipOne had no aerodynamic lift to correct unwanted motion. “You’ve got to be careful that you don’t go over on your back,” Melvill said. “It is real easy to pull so hard that you end up overturning.”

With the nose of SpaceShipOne pointed straight up, a degree or two off one way or the other was not much of a change in angle. But it turned out to be a tremendous change in terms of SpaceShipOne’s stability. So, when Melvill went beyond 90 degrees, he naturally tried to bring the nose back on track. This caused the angle of attack, the direction SpaceShipOne was pointing in relation to the direction of actual motion, to go to zero.

“The wing wasn’t lifting anymore, there was zero lift on the wing, then it departed,” Melvill explained. “It did a snap roll. And that was caused by the design of the airplane. The airplane was designed with a high wing and swept leading edge. Had that been a low wing, it would not have done what it did. We learned that lesson. On the next flight, we didn’t change the airplane at all. We just changed the pull – up schedule.”

The new plan for the trajectory was a more gradual pull-up during boost while making sure never to go to vertical. “And as

Turnaround TimeTurnaround Timelong as that wing is lifting, it won’t stall like that. But when it gets to zero lift, then you get separation on it, and the slightest little perturbation of airplane will cause it to roll or do something odd,” Melvill said.

None of the flights previous to XI had flown at high Mach numbers while at a zero angle of attack. Essentially, SpaceShipOne lost directional stability, so there was no way Melvill could counteract the weak thrust asymmetry, a wandering thrust line, coming from the rocket engine at the time. SpaceShipOne was still rocketing up, so by the time the first few rolls occurred, the atmosphere had disappeared. Aerodynamic forces were not longer causing the rolls, but since there was no air pressure to resist the rolling motion, once SpaceShipOne started to roll, it just kept going and going.

The structural loading on SpaceShipOne from the rolling was very low. Melvill’s safety was never in jeopardy, only his breakfast, which thanks to all of the unusual-attitude training in the Extra 300 aerobat­ic plane, remained in place. The very next day, Scaled Composites not only figured out what caused the rolling departure but also deter­mined a way to keep it from happening again.

As with the first rocket-powered launch of SpaceShipOne, Rutan wanted to fly on a significant day in aviation history. The anniversary of the first man-made object to orbit Earth was approaching. Russia’s Sputnik, as shown in figure 9.9, was launched on October 4, 1957, and circled Earth about 1,400 times at a peak apogee of 588 miles (947 kilometers). This milestone of spaceflight sent the space programs of the United States and the USSR into warp speed.

“We had three days to finesse this in the simulator,” Binnie said. “Between Mike’s flight and the final flight, it was Friday, Saturday, Sunday. It looked promising, but it was still only our sixth powered flight in the vehicle. There was no guarantee that we really under­stood it or that there weren’t some other gremlins that were going to leap out and get us.”

Reaction Control System

Because there is no atmosphere in space, the flight control systems that ordinarily allow an aircraft to move through the air do not work for spacecraft moving through space. Rudders, elevators, and ailerons only work because air moves over them. With no air, they are useless.

In order to maneuver in space, spacecraft take advantage of a simple physics law discovered by Sir Isaac Newton:for every action, there is an equal and opposite reaction.

Without considering a spacesuit, for example, if a person was in space and blew through a straw, the air would move out the straw in one direction and the person would move in the opposite direction.

Figure 6.8 shows an astronaut with a hand-held reaction control system (RCS). To move, he just points the opposite direction, releases a puff of gas, and off he goes in the direction he wants. This, by the way, is the same principle by which a rocket engine works. The RCS thrusters are just miniature rocket engines.

Reaction Control System( ■ >1 Fig. 6.8. In Gemini 4, astronaut Ed White made the first U. S.

spacewalk. To maneuver during his 23-minute extravehicular activity

(EVA), he used a hand-held self maneuvering unit (HHSMU) that shot

little bursts of gas, which allowed him to move around. This device

worked similar to the way SpaceShipOne’s reaction control system works.

NASA-Johnson Space Center

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The Space Shuttle uses a fuel of monomethylhydrazine (MMH) and an oxidizer of nitrogen tetroxide (N204) for its RCS. These pro­pellants react together spontaneously once in contact. As long as each chemical is stored safely separate, they provide the orbiter a simple, reliable, precise, and powerful RCS.

SpaceShipOne had limited time in space and was much less massive than the Space Shuttle. The force generated by these expensive and toxic chemicals was not required. So, puffs of air were sufficient to maneuver SpaceShipOne in space.

After the aerodynamic control authority was gone, the pilot used the RCS to help slow down or null any rotation that had developed while exiting the atmosphere. Each wingtip had roll thrusters, and along the top, bottom, and sides of the fuselage were pitch and yaw thrusters. Each of these thrusters was essentially a port from which high-pressure air could be expelled, and each thruster had a backup. Redundant 6,000-psi bottles of air powered the RCS. By fully extend­ing the rudder petals and the control stick, the pilot maneuvered SpaceShipOne by triggering microswitches that turned the appropriate thrusters either full-on or full-off.

The RCS was also used to get into position for reentry. Scaled Composites had confidence that the feather would self-right SpaceShipOne. However, they did not want to start off upside-down if they didn’t have to.

Tier One Navigation Unit

The pilot had to fly a specific trajectory carefully during a mission. If he deviated, he risked not only failing to reach the target altitude but also missing the prescribed reentry area or, in the extreme case, being too far away from the landing site.

“The aircraft itself was completely manually controlled,” Pete Siebold said. “So, the only feedback the pilot had to how the airplane was flying was through the avionics system.”

It was necessary to develop an avionics system, called the Tier One navigation unit (TONU), for SpaceShipOne. “There really was nothing available within our budget and nothing available off the shelf that suited our needs. So, we had to go develop it ourselves,” Siebold said. The system navigation unit (SNU) and the flight director display (FDD) were the two primary components that made up the TONU.

“We had contracted a company to basically develop the hardware portion of the nav system,” Siebold said. “They built the boxes and put the computers in. They were initially responsible for developing the software of the navigation system as well. However, we ended up making major modifications to that software at the end of the program to make it perform the way we needed it to perform. On the display side, we wrote all the software for the entire program from the beginning.” Aside from being a test pilot, Siebold was the engineer behind most of the software design. Fundamental Technology Systems (FTS), also an Ansari X Prize competitor, provided the hardware and initial software to Scaled Composites.

Acting as the brain of the TONU, the SNU incorporated both a global positioning system (GPS) and an inertial navigation system (INS). It sent guidance and navigational information to the pilot, who saw it on the liquid crystal display (LCD) screen of the FDD in glass- cockpit-type fashion. The SNU navigates along the primary flight axes in six degrees of freedom: the translations of left/right, forward/back, and up/down and the rotations of yaw, roll, and pitch.

Close-ups of the FDD are shown in figure 6.9 and figure 6.10, which also show the similarity between the cockpits of SpaceShipOne and White Knight.

Fly-by-wire was not an option. Siebold said, “It wasn’t warranted for the complexity of this program. Fly-by-wire adds a whole order of magnitude to the whole vehicle development costs. And we really wanted to keep this as simple as possible in order to make this affordable for everybody. That is really the backbone of this program. If you can make it as simple as a Volkswagen, then everybody can afford it. If it needs to be as complex as the Space Shuttle, then nobody can afford it. We really had to push really hard toward making it affordable from the onset.”

The data available to the pilot is based on several modes that correspond to the different phases of flight for SpaceShipOne. Figures 6.11 to 6.14 show various FDD modes, including a boost, a reentry, and a glide. In these modes, the pilot is given trajectory guidance with respect to a detailed map that tracks the position of SpaceShipOne. The FDD automatically stepped through the different modes while flying the mission, but a control allowed the pilot to manually move through the modes in the unlikely event he needed to do so.

Siebold said, “We had the initial boost portion. So, that was the pull up. Then it transitioned to a pseudo-boost mode were every­thing zoomed in and allowed you to track your final target, fly that

Reaction Control System

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Fig. 6.9. A close-up of the flight director display (FDD) for SpaceShipOne is shown in this photograph. The FDD was part of the Tier One navigation unit (TONU) and provided the test pilot with instruments similar to the way a glass cockpit does for an airliner.

Mojave Aerospace Ventures LLC, photograph by David M. Moore

V_____________________________________ J apple onto your target. Once the motor shut down, it transitioned to a coast phase. Once you left the atmosphere, it transitioned into a reentry phase. Once you reentered, it transitioned into three different glide phases. We called them high key, final, and landing phase. And those three phases helped you to find your way back to the airport, and manage your energy so that you’d end up touching down at the place you wanted.”

Sometimes SpaceShipOne nearly pointed straight up, and sometimes it was upside-down. The attitude, or orientation, of SpaceShipOne in flight was key flight information provided on the FDD. “It showed you whether or not you are at wings level,” Siebold explained. “One unique aspect of the display was that as you pitched the nose up, when the horizon on the display disappeared, it still gave you situa­tional feedback to tell you what attitude the aircraft was in.”

A second key piece of flight information was the velocity vector. “What that tells you,” Siebold said, “is the direction in which you are currently flying—the direction in which your velocity is currently heading. That was depicted on the screen with what we called the green apple. It was a green circle with a tail and two wings pointing out of it.” So, with the pilot knowing how SpaceShipOne was oriented and how it was moving in flight, the FDD offered two other bits of crucial flight information. These were the location of the optimum trajectory, represented by the “red donut,” and where SpaceShipOne was with respect to it, which was the “green apple.”

In a presentation at NASA Ames, Doug Shane had given the follow­ing succinct description: “The goal is to take that green velocity vector and put it right over that red donut, because that is the flight-director cue. And that gets you to the reentry point that you want. Very simplemindedly, your task is only to get those two circles closed up as quickly as you can. And that establishes essentially a vertical trajectory and gives you the best performance that you can get.”

In addition, the SNU monitored and recorded how the systems of SpaceShipOne were performing and fed this information to the FDD, where it was displayed. “It acted as a caution/warning/advisory system,” Siebold said. “It told you if there is any parameter out of limits, or if

Reaction Control System

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Fig. 6.10. The inside of White Knight’s cockpit, shown here, is remarkably similar to the cockpit of SpaceShipOne. Even the instrumentation and controls are nearly identical, with the obvious exception that SpaceShipOne has rocket-engine controls and White Knight has jet-engine controls. Since White Knight started flying about a year before SpaceShipOne, this allowed Scaled Composites to build up confidence in the instruments prior to flying SpaceShipOne. Also, White Knight could be used as a trainer for SpaceShipOne. Mojave Aerospace Ventures LLC, photograph by Scaled Composites

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there is anything out of limits that would cause you to abort the flight. We had a small list of parameters that if they ever exceeded some allowable range, they’d flash a big red sign that said ‘abort.’”

During the rocket engine burn, things happened fast. There was not a lot of time to make decisions. The TONU did not automatically control SpaceShipOne. “The pilot still had to look at the information, digest it, and make the appropriate decision with that information,” Siebold said.

Data that the SNU collected then displayed to the pilot on the FDD was also transmitted real-time to Mission Control on the ground by a radio frequency (RF) telemetry downlink. In Mission Control, the data reduction system (DRS) collected, processed, and stored all the trans­mitted data and made it accessible to everyone in Mission Control.

Abort Contingencies (9G)

Melvill continued to expand the flight envelope and to test the feather. Figure 7.12 shows him inside the cockpit pulling the feather control. But he had another important task to complete.

All this flight testing was really aimed at one goal: SpaceShipOne flying a spaceflight. So, every step along the way had to accomplish something that would bring that goal just a little bit closer. But this also meant that contingencies had to be worked out. “Probably the biggest fear we had for every flight was having to abort,” Doug Shane said about the rocket-powered flights.

Scaled Composites had very good confidence in how SpaceShipOne flew by this point. And after an extensive rocket-engine test program on the ground, they also had a good feeling about the rocket engine. So, Scaled Composites felt a safety incident was not likely to result from flying SpaceShipOne or firing the rocket engine. But an abort during a test flight was much more plausible, considering one had already occurred.

If SpaceShipOne aborted while full of fuel and oxidizer, then this would be much too much weight for it to handle during landing. “You

Подпись: г
Подпись: л

Fig. 7.15. The photograph shows Brian Binnie preparing right before his first time flying SpaceShipOne. This would be the last glide flight prior to the start of SpaceShipOne’s rocket – powered test flights. Mojave Aerospace Ventures LLC, photograph by David M. Moore

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have to actually dump nitrous to get rid of about 3,000 pounds (1,360 kilograms) of mass. But you couldn’t deal with the rubber in the rocker motor,” Shane said.

For this test flight, Melvill evaluated the emergency handling and landing characteristics. Figure 7.13 shows SpaceShipOne dumping the ballast, which it used to alter the CG during testing. Additional mod­ifications were also made to the landing procedures, and figure 7.14 shows SpaceShipOne’s smooth touchdown.

The Feather

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.

X2: Winning the Ansari X Prize (17P)

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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X2: Winning the Ansari X Prize (17P)Подпись: лFig. 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.”

X2: Winning the Ansari X Prize (17P)C ^

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

V J

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X2: Winning the Ansari X Prize (17P)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

X2: Winning the Ansari X Prize (17P)r~

X2: Winning the Ansari X Prize (17P)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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Подпись: лFig. 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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X2: Winning the Ansari X Prize (17P)f

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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X2: Winning the Ansari X Prize (17P)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

Подпись: Figure 9.18 shows Peter Diamandis and Anousheh Ansari celebrating with Brian Binnie, Burt Rutan, Paul Allen, and Sir Richard Branson. “It was just a feeling of relief that everything had worked flawlessly,” Paul Allen recalled. “A mix of elation and relief I think is what I described at the time. And you are proud for Burt and his team. In the back of your mind you are thinking like maybe this does open the door for a lot of possibilities in the future in terms of private space tourism. I was just very excited and relieved, just an amazing mixture of emotions.” With the Ansari X Prize awarded, commercial space travel officially launched off. Diamandis’ vision of a new way of thinking about space flight became reality, and Rutan with his team from Scaled Composites provided the way. Eight years was a long race, but the accomplishments during this time frame far outreached what was once thought possible. Подпись: The will was now strong enough to overcome the energy barrier to space, much the way the mystical sound barrier was broken in the 1940s to usher in supersonic flight. Paul Allen saw to it that Burt Rutan would have the chance to show his stuff and prove to the world that the impossible wasn’t impossible. And Brian Binnie’s perfect performance flying SpaceShipOne, gave all the reason to Sir Richard Branson and his newly formed Virgin Galactic that commercial space travel was right. “Burt has the world’s greatest garage,” Paul Allen said. “We built a rocket in the world’s greatest garage, and we actually got into space and back, and everybody was safe. And it won a prize. It is hard to explain the excitement of that. And the crowds being there celebrating that with you was just amazing.”

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X2: Winning the Ansari X Prize (17P)r ; >

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

V__________________ )

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

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SS1: SpaceShipOne

Time stamp and speaker

Dialogue

Notes

7:49:17 MM

"SCUM status?"

The Scaled Composites Unit Mobile (SCUM) was a mobile ground control station.

7:49:19 DS

"SCUM is go for release and ignition, elevons to go."

BB pushes the control stick forward, preparing for release.

7:49:22 MM

"Three. Two. One."

7:49:25 MM

"Release."

7:49:27 BB

"Release."

7:49:28 BB

"Armed."

7:49:28 BB

"Fire."

7:49:32 BB

"Good light."

7:49:37 DS

"Coming up ten seconds, Brian."

Rocket engine burn time at 10 seconds.

7:49:39 BB

"Copy."

7:49:42 DS

"Rates look good and low."

7:49:46 DS

"Okay, start the nose-down trim."

The trajectory must be timed in order to end up at zero angle of attack as late as possible.

7:49:49 DS

"Looking great at twenty seconds."

Rocket engine burn time at 20 seconds.

7:49:54 DS

"Doing okay?"

7:49:55 BB

V

"Doing alright."

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

7:49:58 DS

"Copy that. Thirty seconds, a little nose up trim is probably okay now."

Rocket engine burn time at 30 seconds.

7:50:02 MM

"You look great."

7:50:07 BB

"Starting to settle out."

7:50:09 DS

"Okay, forty seconds."

Rocket engine burn time at 40 seconds.

7:50:10 DS

"The energy’s on the line. The trajectory looks good."

The actual trajectory is tracking with the predicted trajectory.

7:50:13 BB

"Copy."

7:50:16 DS

"Touch of nose up trim."

7:50:19 DS

"Fifty seconds."

Rocket engine burn time at 50 seconds.

7:50:21 DS

"Two hundred energy."

This reading stands for a projected altitude of 200,000 feet (60,960 meters) for SS1. It does not stand for SSI’s actual altitude. Both MC and AFFTC use energy altitude predictors to project the maximum altitude SS1 would reach if its rocket engine were to shut off and SS1 were to coast the remainder of the way up. The projected altitude gives an indication at any given time whether or not SS1 will reach the target altitude of 328,000 feet (100,000 meters).

7:50:22 DS

"A little right roll trim."

A slight correction is made to the trajectory.

7:50:26 DS

"Nose pitch up, Brian, nose up trim."

7:50:30 BB

"There is the shaking."

The liquid to gas transition, which occurs as the N20 begins to run low in the oxidizer tank, causes this to happen.

7:50:31 DS

"Okay."

7:50:33 DS

"Roll right."

7:50:36 DS

"Three hundred thousand."

The predicted altitude is 300,000 feet (91,440 meters).

7:50:41 DS

"Three twenty-eight."

The predicted altitude is 328,000 feet (100,000 meters).

7:50:44 DS

"Radar is three twenty-eight."

The predicted altitude is 328,000 feet (100,000 meters) as measured by AFFTC.

7:50:45 BB

"Copy that."

7:50:48 DS

"Three fifty suggest shutdown."

The rocket engine is still firing, and if it is shut down at this point, SS1 will coast to 350,000 feet (106,700 meters).

7:50:53 BB

"Roger. Shutdown."

BB lets the rocket engine burn an extra 4-5 seconds.

7:50:58 BB

"And the rates look good."

7:51:00 DS

"Okay. Copy that."

7:51:01 DS

"You are going to want to track north for the entry."

A box, approximately 2.5 square miles in size, is set by AST for SS1 to make the reentry.

7:51:03 DS

"You are just across the orange line on the south."

The orange line is an AST boundary.

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7:51:05 DS

"Uh, you are good east, uh, east-west of Mojave."

7:51:08 ВВ

"Okay, I see that."

7:51:10 DS

"Okay."

7:51:14 DS

"Eighty-four seconds."

The rocket engine burns for a total time of 84 seconds.

7:51:15 DS

"Eighty-four seconds, the shutdown is clean and the feather is green."

7:51:19 BB

"Feather unlock."

7:51:24 BB

"Feather. . . moving."

7:51:27 BB

"RCS on."

The reaction control system (RCS) controls motion of SS1 in space.

7:51:28 DS

"Copy that, Brian. It’s moving, and it’s green."

The feather is extending upward.

7:51:30 DS

"CTN is a little warm but looking fine."

The CTN is the case/throat/nozzle assembly of the rocket engine.

7:51:33 DS

"RCS A looks nominal."

The pressure for the RCS looks good.

7:51:37 BB

"I show the feather up."

7:51:39 DS

"We do show the feather all of the way up now. It is green."

7:51:48 BB

"The trim is set."

7:51:49 DS

"Looks great."

7:51:51 BB

"And I’m upside down."

7:51:53 DS

"Okay."

7:51:57 DS

"You are going to want to orient northwest for the entry, Brian."

SS1 should be oriented so that it points toward Mojave.

7:52:00 BB

"Okay, Doug. Copy that, northwest"

7:52:02 DS

"Sound great. Feel good?"

7:52:04 BB

"I’m feeling great."

7:52:05 DS

"Copy that."

7:52:07 BB

"Better get the camera out."

7:52:09 DS

"Roger that."

7:52:14 BR

"X-15 record."

This comment is made in MC and not heard over the radio. SSI’s actual altitude is above the highest altitude reached by the X-15. The predicted altitude is no longer used.

7:52:16 DS

"X-15."

7:52:21 BB

"Outstanding."

7:52:22 MM

"That’s outstanding. I knew it."

)

(

7:52:37 BR

"Ten thousand feet over X-15."

This comment is made in MC and not heard over the radio.

7:52:48 BB

"Boy, it’s really quiet up here."

7:52:59 DS

"Okay, flight is through this position coming downhill through three fifty."

The actual altitude of SS1 is 350,000 feet (106,700 meters).

7:53:03 DS

"And current position is five southwest."

7:53:06 DS

"Correction, five south of the bull’s-eye."

The bull’s-eye is the center of the AST box.

7:53:08 DS

"Looks like the entry point is between main base and north base."

This is to let the chase planes know that reentry will occur between Mojave Air and Space Port and Edwards Air Force Base.

7:53:17 DS

"Brian, if you can keep it upright for GPS, that’s good."

7:53:19 DS

"And, again, orient northwest please for the entry."

7:53:25 BB

"Copy that, Doug."

7:53:36 DS

"And Brian, a little blip of right yaw trim would be good."

7:53:43 DS

"That looks great."

7:53:45 DS

"Doing okay?"

7:53:48 BB

"I’m doing great, Doug. Uh, camera is, uh, stowed again."

7:53:54 DS

"Copy that, passing two six zero."

The actual altitude is 260,000 feet (79,250 meters).

7:54:03 BB

"And it’s northwest you want for the heading right?"

7:54:06 DS

"Affirmative."

7:54:09 DS

"That’ll point you back at high key."

High key is a glide mode of the TONU.

7:54:21 DS

"All systems are green here, Brian."

7:54:22 DS

"Don’t worry about temps in the back end."

7:54:24 DS

"We’re looking good here."

7:54:26 MS

"Alpha’s got a visual."

The Alpha Jet chase plane spots SS1.

7:54:27 BB

"Okay, here comes the g’s."

7:54:29 DS

"Copy that."

7:54:31 DS

"One hundred fifty thousand."

The actual altitude is 150,000 feet (45,720 meters).

7:54:37 BB

"There’s three."

BB is referring to the number of reentry g’s.

7:54:41 DS

"Max Mach is past three two six."

SS1 reaches a maximum of Mach 3.25.

7:54:45 BB

"Five g’s."

7:54:58 DS

"Peak g is passed."

X2: Winning the Ansari X Prize (17P)

 

7:55:00

BB

"Copy that."

7:55:02

DS

"You’re looking great on glide range."

7:55:03

DS

"Coming through seventy five thousand."

7:55:12

DS

"Ok, we have had no GPS."

7:55:13

DS

"So, you are a little higher than your indication Brian."

7:55:15

DS

"We are showing seventy but radar is looking like seventy-five now."

7:55:20

DS

"And, uh, roll right if you can, that would be good."

7:55:23

BB

"Okay."

7:55:27

DS

"Okay, there is seventy thousand radar."

7:55:29

DS

"Feather at your discretion."

7:55:31

DS

"Uh, might give it another couple seconds."

7:55:32

BB

"It feels a little, ah, loosy goosy right now."

7:55:35

DS

"Copy that."

7:55:40

DS

"You are going to want to get the roll trim back to neutral as you defeather."

7:55:45

DS

"Radar altitude sixty-three now, sixty-three thousand."

7:55:48

BB

"Okay, I feel good about the feather."

7:55:50

DS

"Yeah, we do here."

7:55:55

DS

"RCS off when you can."

7:55:58

BB

"RCS is off."

7:55:59

DS

"Copy."

7:56:00

DS

"You are going to want to start a right turn to the north as soon as you recover."

7:56:04

BB

"Copy."

7:56:08

DS

"Radar shows fifty-four thousand."

7:56:17

BB

"I show the feather locked."

7:56:18

MC

Cheering in mission control.

7:56:19

DS

"The feather is locked and it is green."

 

The actual altitude is 75,000 feet (22,860 meters).

 

DS is reporting altitude in thousands of feet.

 

The actual altitude is 70,000 feet (21,340 meters).

 

There is no hurry, as BB is in good glide range, and the vehicle should fly better.

 

The actual altitude is 63,000 feet (19,200 meters).

 

The actual altitude is 54,000 feet (16,460 meters).

 

X2: Winning the Ansari X Prize (17P)

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

Energy Altitude Predictor

During the test flight, the TONU displayed a readout from the energy altitude predictor during the boost phase. Developed by aerodynamicist Jim Tighe, it worked by making calculations based on factors like SpaceShipOne"s speed and thrust. The pilot used this to decide when to turn off the rocket engine because SpaceShipOne was roughly half the distance to apogee after rocket-engine shutdown. For the second half, it coasted the rest of the way up.

The pilot needed a way to ensure he didn’t run the rocket engine too long or too short. The initial powered flights relied on a timer, but using the energy altitude predictor yielded much better results. By looking at the readout of the energy altitude predictor, the pilot had a very good idea of the altitude SpaceShipOne would reach if the rocket engine shut down at that exact moment.

For example, the energy altitude predictor may have read 200,000 feet (60,960 meters), but in actuality, SpaceShipOne may have only been at an altitude of 80,000 feet (24,380 meters). So, if

SpaceShipOne shut down the rocket engine at that precise moment, it would coast to an apogee of about 200,000 feet (60,960 meters). This would be 128,000 feet (39,010 meters) short of the Ansari X Prize requirement. Therefore, the pilot wouldn’t have shut down the rock­et engine at this point, but he would have waited until the energy alti­tude predictor read at least 328,000 feet (100,000 meters).