WhiteKnightTwo Resumes Flight Tests

Guy Norris guy_norris@aviationweek.com

Scaled Composites has completed the third, and so far longest, test flight of Virgin Galactic's WhiteKnightTwo (WK2) carrier aircraft being developed to ferry the SpaceShipTwo (SS2) spacecraft to its release altitude.

During the flight, which took place from Mojave, Calif., on March 25, the WK2 flew for over 2.5 hours, and reached a maximum speed of 140 knots and an altitude of over 18,000 feet.

Virgin Galactic says the flight also saw a further seven test points successfully completed, including "in flight engine restarts, engine thrust asymmetry assessment and continued expansion of WK2's operating envelope and evaluation of WK2's handling qualities."

The flight included further tests of the stability and handling characteristics and the improvements made as a result of the earlier flights in December 2008 and Feb. 5, 2009. The aircraft's twin fins have been fitted with vortex generators to improve rudder effectiveness and directional stability. The control issues cropped up during WK2's first flight on December 21, which lasted for 1.5 hours (Aerospace DAILY, Dec. 23).

Captive carry flights with the SS2, which will be unveiled in the third quarter of 2009, are not expected to begin until next year towards the end of a planned 18-month long test program. Initial space tourism flights are planned to start around 2011. In addition to launching SS2, the WK2 has also been developed for a range of science payload and training applications, including potentially launching an unmanned rocket capable of putting a satellite into low-Earth orbit.

Photo credit: Virgin Galactic/Mark Greenberg