Feather at Supersonic (14P)

Nearly one full year since flight testing began, SpaceShipOne was on the verge of making a spaceflight. One critical piece of infor­mation was missing, though. “The object of that flight was to do a supersonic feathered reentry,” Mike Melvill said. “We needed that data before we could go beyond that.” Figure 8.7 shows SpaceShipOne mated up to White Knight in preparation for the third powered flight.

Ten seconds after releasing from White Knight at 46,000 feet (14,020 meters), Melvill lit off the rocket engine. Figure 8.8 shows a dramatic rearward view of the rocket engine’s fiery plume and exhaust.

“During the boost after he reached the vertical part of the trajec­tory, the avionics display started flickering and then went blank,” Doug Shane said. “We all had good displays in the ground station. And Mike said, T looked out the window, and we were going pretty much straight up. So, I stayed with her.’ Gotta love a guy like Mike. Of course it came back on as soon as the motor shut down.”

The rocket engine burn duration was set by a timer. As Melvill looked out the windows to navigate, SpaceShipOne boosted to 150,000 feet (45,720 meters) and Mach 2.5, and then its rocket engine shut down. SpaceShipOne


Flight Test Log Excerpt for 14P

Date: 13 May 2004

Flight Number Pilot/Flight Engineer

SpaceShipOne 14P Mike Melvill

White Knight 56L Brian Binnie/Matt Stinemetze

Objective: The third powered flight of SpaceShipOne. 55 seconds motor burn time. Handling qualities during boost and performance verification. Reaction control system use for reorientation to entry attitude. Supersonic feather stability and control.

Feather at Supersonic (14P)




Feather at Supersonic (14P)

Подпись: у
Подпись: Ґ s ^ Fig. 8.8. SpaceShipOne had several video cameras mounted inside the cockpit and on its exterior. This video-capture image shows a rearward view from the top of the fuselage of the rocket engine's plume and exhaust. Mojave Aerospace Ventures LLC, video capture provided courtesy of Discovery Channel and Vulcan Productions, Inc. к ) continued its ascent to an apogee of 211,400 feet (64,430 meters). But since Melvill had lost his avionics during boost, the trajectory was not exactly spot on. “I was doing forward loops, or something, at the top. It slowed down but came back in, and then it was swinging around a lot.” Melvill used the RCS to dampen the oscillations. In the feather configuration, SpaceShipOne reentered the atmosphere at Mach 1.9 and 3.5 g. SpaceShipOne quickly stabilized and made its feathered “carefree”

Fig. 8.7. The photograph shows SpaceShipOne being prepared for its third rocket-powered test flight. SpaceShipOne had made its very first test flight just about a year earlier. The main goal of this test flight was to evaluate the performance of the feather at supersonic speed. Mojave Aerospace Ventures LLC, photograph by David M. Moore

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Feather at Supersonic (14P)Fig. 8.9. SpaceShipOne reached an apogee of 211,400 feet (64,430 meters), and the video camera in the tail boom recorded the feather in the extended position. While high above Los Angeles, SpaceShipOne was technically not in space, even though the curvature of Earth can be clearly seen. However, the curvature is somewhat exaggerated due to the auto focus lens used. Mojave Aerospace Ventures LLC, video capture provided courtesy of Discovery Channel and Vulcan Productions, Inc.

V_________________________________________________ J

Feather at Supersonic (14P)

reentry just as expected. It actually descended more smoothly at supersonic speeds than it did at subsonic speeds. Figure 8.9 shows SpaceShipOne above Earth, with Los Angeles and the California coast­line in the background.

Back on the ground, engineers traced the avionics malfunction to a dimmer, a small electrical component. And since the thermal protection data looked good, Scaled Composites felt that SpaceShipOne performed well enough to continue forward.

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