Virgin Galactic spaceship lands safely

Virgin Galactic's SpaceShipTwo has successfully glided through its first free-flying test, more than two years after a pilot died when the first craft crashed.

Virgin Galactic's SpaceShipTwo has successfully glided through its first free-flying test. (AAP)

Sir Richard Branson has watched on as Virgin Galactic's second SpaceShipTwo successfully glided through its first free-flying test, more than two years after a man was killed when the first craft crashed.

The SpaceShipTwo, dubbed VSS Unity, landed in Mojave, California, about 10 minutes after it cleanly detached from its carrier aircraft WhiteKnightTwo.

Virgin Group founder Sir Richard joined Virgin Galactic chief executive George Whitesides and other onlookers to witness the test flight, smiling and clapping as VSS Unity's two pilots manned the vehicle back on to the runway.

Astronaut Tim Peake also sent his well-wishes to the Virgin team as the test glide got under way.

He tweeted: "Good luck with this new phase of the test programme @virgingalactic - safe flight #pushingboundaries."

After further glide flights, the next step in the group's ongoing mission to make space tourism a reality will be to conduct rocket-powered flights to test the Unity's hybrid motor.

Last year, an investigation by the US National Transportation Safety Body found a fatal October 2014 crash was caused by a catastrophic structural failure triggered when the co-pilot unlocked the craft's braking system early.

The spaceship broke apart over the Mojave Desert during a powered test flight, killing co-pilot Michael Alsbury and seriously injuring pilot Peter Siebold.

Virgin Galactic has said it will officially launch operations from Spaceport America in New Mexico with paying passengers "once it believes it is safe to do so" and it has received all regulatory approvals.