Trending: Lawsuit claims Amazon and freight partner worked truck driver ‘into the ground,’ causing him to crash
SpaceShipTwo with feathered wings
Long-range imagery shows the SpaceShipTwo plane known as VSS Unity with its wings in the feathered position for braking. ( / Trumbull Studios via Virgin Galactic)

Virgin Galactic passed another essential milestone today in the flight test program for VSS Unity, its upgraded SpaceShipTwo rocket plane, by bending its wings into a “feathered” position for the first time in the air.

The company hailed the gliding test as a success in a series of tweets. Test pilots Mark Stucky and Mike Masucci were at VSS Unity’s controls, while Nicola Pecile and CJ Sturckow piloted the White Knight Two carrier airplane. Flight test engineer Dustin Mosher rode in the mothership as well.

The wing-feathering system is a crucial element for SpaceShipTwo, as it was for SpaceShipOne’s prize-winning spaceflights back in 2004.

The flight profile requires a slowdown from supersonic speeds during the descent from the edge of space. To do that, SpaceShipTwo has to angle its wings for a braking effect, similar to the floating effect produced by the feathers on a shuttlecock during a badminton game.

Aerospace designer Burt Rutan came up with the design as a way to guarantee a “carefree re-entry,” but the technology turned out to be anything but carefree in 2014.

That October, the wing-feathering system was deployed prematurely during a rocket-powered ascent of VSS Enterprise, the first SpaceShipTwo plane. That resulted in the catastrophic breakup of the craft, which in turn led to the death of co-pilot Mike Alsbury and a harrowing fall for test pilot Pete Siebold. Siebold’s parachute deployed as he fell, but he nevertheless suffered serious injuries.

In the wake of the accident, investigators recommended changes in the wing-feathering system to guard against premature deployment, and Virgin Galactic incorporated those changes into the design for the second SpaceShipTwo.

Testing the rebuilt system was a primary objective for today’s flight at the Mojave Air and Space Port in California. Before this morning’s takeoff, Virgin Galactic said the wings would be feathered shortly after Unity was dropped from the carrier aircraft for a gliding flight back to the runway:

“The feather will be raised at lower altitudes — and consequently thicker atmosphere — than would be the case during a full mission to space. This will provide a rigorous test of the feather system in the air, complementing extensive testing already completed on the ground.”

After the flight, Virgin Galactic said the initial reports from the pilots and from ground controllers were “extremely encouraging.” This was the fourth glide flight since last December.

If all goes well, Virgin Galactic and its sister subsidiary, The Spaceship Company, are expected to begin rocket-powered test flights by the end of this year, climaxing with ascents to outer-space altitudes. Last week, Galactic Ventures CEO George T. Whitesides said during a Senate subcommittee hearing that the company was on track to start flying passengers to space from Spaceport America in New Mexico by the end of next year.

About 700 customers, including celebrities such as Justin Bieber and Katy Perry, have signed up for spaceflights at a cost of as much as $250,000 per ticket.

Subscribe to GeekWire's Space & Science weekly newsletter


Job Listings on GeekWork

Find more jobs on GeekWork. Employers, post a job here.