After weather scrubbed a pre-holiday powered flight attempt last month, SpaceShipTwo took to the skies yesterday, performing its third powered flight. After being released from its WhiteKnightTwo carrier aircraft shortly after 8 am PST (11 am EST, 1600 GMT) Friday at an altitude of 14,000 meters (46,000 feet), SpaceShipTwo fired its hybrid rocket engine for 20 seconds, achieving a top speed of Mach 1.4 and peak altitude of 21,600 meters (71,000 feet) before gliding to a runway landing at the Mojave Air and Space Port in California, the company reported in a statement.
The performance of the flight was not much different from the vehicle’s previous two powered flights. In September, SpaceShipTwo fired its engine for 20 seconds as well, flying a little faster (Mach 1.43) but a little lower (21,000 meters) than Friday’s flight. On its inaugural powered flight in late April 2013, SpaceShipTwo fired its engine for 16 seconds, going only a little slower and lower than the following two flights.
Virgin billed this flight, though, as more of a flight demonstration and training mission. Virgin said that during the flight they tested the vehicle’s reaction control system (RCS), thrusters that maneuver the vehicle when above the atmosphere. The flight also tested reflective material placed on the inboard surfaces of the vehicle’s twin tail booms, which is intended to reduce temperatures on those surfaces while the rocket motor fires. The flight was also the first time that Virgin Galactic’s chief test pilot, David Mackay, was at the controls of SpaceShipTwo, with Scales Composites test pilot Mark Stucky as co-pilot.
Virgin’s very slow pace of test flights—Friday’s test took place more than eight months after the first powered flight—have raised questions about when the vehicle will be ready to fly in space and, later, begin commercial service. In Friday’s statement about the test, Virgin executives insisted that they would achieve both milestones this year. “I couldn’t be happier to start the New Year with all the pieces visibly in place for the start of full space flights,” said Sir Richard Branson in the statement. “2014 will be the year when we will finally put our beautiful spaceship in her natural environment of space.”
“With each flight test, we are progressively closer to our target of starting commercial service in 2014,” added Virgin Galactic CEO George Whitesides. That goal will, presumably, require a more active pace of test flights in the months to come.