VSS Enterprise - Flight Test Program

Flight Test Program

Projections by Virgin Galactic in 2008 called for test flights to begin in late 2009 and commercial service to start in 2011.

In October 2009, Virgin Galactic CEO Will Whitehorn outlined the flight test program for SpaceShipTwo. The test program includes seven phases:

1. Vehicle ground testing.
2. Captive carry under White Knight Two.
3. Unpowered glide testing.
4. Subsonic testing with only a brief firing of the rocket.
5. Supersonic atmospheric testing.
6. Full flight into suborbital space.
7. Execute a detailed and lengthy appraisal process with the FAA/AST to demonstrate the system's robustness and eventually obtain a commercial launch license to begin commercial operations.

On 22 March 2010, the SpaceShipTwo vehicle VSS Enterprise underwent a captive carry test flight, with the parent White Knight Two aircraft, VMS Eve, performing a short flight while carrying the Enterprise. A second test flight was made on 16 May 2010, reaching SS2's launch altitude (51,000 feet) and lasting nearly five hours, in order to facilitate "cold soak" testing of SS2's avionics and pressurization system. Thereafter, "a simulated spaceship descent/glide mission was made from altitude." Between these two flights, the SpaceShipTwo airframe was modified by the addition of two interior fins, with one fin being added to the inside (rocket-side) of each of the craft's twin vertical stabilizers.

On 15 July 2010, VSS Enterprise made its first crewed flight. The craft remained attached to VMS Eve as planned, and underwent a series of combined vehicle systems tests. The flight lasted a total of 6 hours and 21 minutes. A second, similar crewed flight of VSS Enterprise and VMS Eve was carried out on 30 September 2010, lasting approximately 5 hours. Among the objectives of these flights was the improvement of pilot proficiency, and the results of the flights were deemed to show that the systems were capable of supporting future glide missions.

On 10 October 2010, VSS Enterprise made its first manned gliding test flight. It was released from VMS Eve at 45,000 feet and glided to a safe landing at the Mojave Air and Spaceport. A second gliding test flight took place on 28 October 2010 and a third on 17 November 2010. As of December 2010, Scaled reported that the flight test program is exceeding expectations. The fourth test flight took place on 13 January 2011, while the fifth and sixth glide flights occurred on 22 and 27 April 2011, respectively. Following this, the feathered reentry configuration was tested in flight on 4 May 2011, with weekly test flights continuing through the end of May. On 9 June 2011, SS2 failed to separate from White Knight Two during its 11th planned glide flight due to a technical problem. Testing resumed with five successful glide flights in June 2011.

In July 2011, after 15 successful glide flights, flight testing of SS2 was halted for two months while planned revisions to the spaceplane were made. Flight tests resumed in late September 2011, although the 16th glide flight – on 29 September – was marred by a brief loss of control aboard SS2, forcing the crew to utilise the feathered wing configuration to land safely. This test was followed by another hiatus, during which some of the spacecraft's engine components were installed. In June 2012, Scaled Composites received an FAA permit to conduct rocket-powered supersonic test flights. SpaceShipTwo flight tests resumed in June 2012. These tests will include both further aerodynamic drop tests and full-scale rocket-powered demonstrations.