Virgin Galactic’s successor to its SpaceShipTwo spacecraft has successfully performed its first unpowered glide and landing. The event comes two years after the tragic fatal crash of the spaceship’s first iteration over the Mojave Desert, when pilot Michael Alsbury was killed and his co-pilot Peter Siebold seriously injured. In July 2015, a nine-month investigation by the National Transportation Safety Board concluded that the incident was caused by pilot error and poor safety procedures.
On 4 December the second iteration, VSS Unity, was safely steered by pilots Mark Stucky and Dave Mackay after being taken to an altitude of 50,000 feet by Virgin’s four-engine WhiteKnightTwo. The entire flight took one hour and 20 minutes, only ten of which consisted of the free-glide, during which VSS Unity reached a maximum speed of Mach 0.6 (about 735 km/h). It was the VSS Unity’s fifth flight with WhiteKnightTwo carrying it, but the first time it was piloted and landed alone.
Missions like these are carried out over and over again so Virgin Galactic ground crew can collect streams of data to check every element of engineering is working as it should. A statement on the flight said: “We have not yet reached the rocket-powered phase of the test flight program – first we need to gather test flight data to confirm our analyses and calculations about how VSS Unity will perform in a wide variety of real-world flight conditions. An initial look at the data as well as feedback from our two pilots indicate that today’s flight went extremely well, but we’ll take the time to properly and thoroughly analyse the vehicle’s performance before clearing the vehicle for our next test.”
Virgin Galactic has always been transparent about its operations, but given the 2014 crash and the concerns over its future at that time, it seems to be set on relaying just how cautious it plans to operate, going forward. Its final course, though, has not wavered. “We’re looking forward to getting back into the skies as soon as the engineers say we are ready to do so.”
VSS Unity was revealed earlier this year on 19 February, and approved for flight tests in August.
The company has spent two years fixing the procedural errors that allowed for the fatal 2014 crash, when the spacecraft came apart mid-flight in just seconds. The post-crash investigation concluded Alsbury had prematurely unlocked a “feathering system” designed to help the spaceship reduce speed as it begins its descent, by angling its tail wings. SpaceShipTwo had not reached the correct speed at which the feathering system could safely be engaged, and as a result, it deployed too fast. Safety measures have since been put in place, and other changes have been made to the spacecraft including to its fuel system.
VSS Unity is the first spaceship to be manufactured in-house by a Virgin subsidiary, and is flown by Virgin pilots – in 2014 it was flown by pilots employed by Scaled Composites, the company that manufactured the first SpaceShipTwo