made from [launch] 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 crewed gliding test flight. It was released from VMS Eve at 45,000 ft (13,700 metres) 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. , Scaled reported that the flight test program was 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. In September 2012, Virgin Galactic announced that the unpowered subsonic glide flight test program was essentially complete. The company