Scaled Composites tested the feathering re-entry mechanism of the SpaceShipTwo in flight for the first time on May 4.
The test, conducted during the seventh glide flight of the 60-ft.-long, 42-ft.-wingspan commercial spaceship, was performed shortly after release from the WhiteKnightTwo carrier aircraft at 51,500 ft. After attaining a stable glide attitude, the test crew, comprising Scaled Composites’ test pilots Pete Siebold and Clint Nichols, activated the feathering mechanism to rotate the tail section up to a 65-deg. angle relative to the fuselage. The aircraft maintained a level pitch while descending almost vertically at around 15,500 ft. per minute for 1 min. and 15 sec.
The feather mechanism was then used at around 33,500 ft. to reconfigure SS2 for landing, which was achieved with a smooth touchdown at Mojave, Calif., some 11 min. 5 sec. after initial release. The test flight was a key evaluation of the feathering system, which was also used successfully on the SpaceShipOne suborbital vehicle. The device reconfigures the vehicle while in the vacuum of space and creates very high drag as it descends through the atmosphere. As well as providing a self-stabilizing mechanism for re-entry, the high drag and low vehicle weight combination means that skin temperatures remain relatively low during re-entry, thereby eliminating the requirement for conventional thermal protection systems.
The May 4 test follows a recent ramp-up in flight test activity, marking the third glide flight of SS2 in 12 days. George Whitesides, CEO and President of Virgin Galactic, says the increase in tempo reinforces “… the fast turnaround and frequent flight-rate potential of Virgin Galactic’s new vehicles. We have also shown this morning that the unique feathering re-entry mechanism, probably the single most important safety innovation within the whole system, works perfectly. This is yet another important milestone successfully passed for Virgin Galactic, and brings us ever closer to the start of commercial operations.”
In the buildup to the feathering test, SS2 completed two glide flight tests over five days, including a 16-min., 7-sec. glide on April 27 which represents the longest flight to date. The increased tempo comes as settled weather continues to dominate the skies over southern California after weeks of unsettled conditions. The flights also evaluated stability and control and follow refinements to the vehicle’s aerodynamics and low-speed handling qualities. Building on the incremental envelope expansion approach established with SpaceShipOne (SS1), the next test phase beyond feather testing will involve higher speed subsonic flight with a short burst of thrust from a Sierra Nevada-developed RM2 rocket, which will power all vehicles.