Virgin Galactic has released a video showing close up video of SpaceShipTwo’s first feather flight. The eleven minute, 5 second flight took place earlier this month and was the 7th glide flight of the new space ship. An eighth flight was completed last week.
After establishing a stable glide, test pilot Pete Siebold raised the twin booms that comprise the tail of SS2 into the feather position. On an actual sub-orbital space flight, this would be done while still in space where there would be no aerodynamic forces on the vehicle.
During the test flight, SS2 was dropped from 51,000 feet and the change in configuration to the feather position appear to cause a significant nose up pitch attitude during the transition. Once the tail surfaces are raised to about 65 degrees and SS2 is established in the feather position, the space craft descends nearly vertically. In the feather position, SS2 appears to be closer to a flat pitch attitude with some oscillations in pitch, roll and yaw.
The feather position allows the space craft to reenter the atmosphere at a slow enough speed to reduce the heating problems that can occur as friction with the atmosphere increases. It also simplifies the process compared to needing a precise glide angle for reentry in order to avoid skipping off of the atmosphere.
During a flight with the X-15 program in 1962, test pilot and future astronaut Neil Armstrong skipped off of the atmosphere in the rocket plane and ended up flying well past his landing spot at Edwards Air Force Base. Aerodynamic forces on the X-15 were not strong enough to turn around until he was over Pasadena, 45 miles to the south. Armstrong did managed to stretch his glide and make it back to the dry lake bed near Edwards Air Force Base and also recorded the longest flight of the X-15 program.
Virgin Galactic hopes to begin offering passenger flights in SpaceShipTwo as early as next year.
Video: Virgin Galactic