Houston Chronicle by Jeff Foust — December 13, 2018
A test flight more than a decade in the making is scheduled to take place Dec. 13 as Virgin Galactic’s SpaceShipTwo suborbital vehicle is set to make its highest and fastest flight to date, one that, if all goes well, will take it beyond one boundary of space.
The test flight is scheduled to begin at around 10 a.m. Eastern when the WhiteKnightTwo aircraft carrying the SpaceShipTwo vehicle named VSS Unity takes off from Mojave Air and Space Port here. The aircraft will fly to an altitude of about 13,100 meters before releasing SpaceShipTwo about 45 to 60 minutes after takeoff.
SpaceShipTwo, flown by pilots Mark Stucky and C.J. Sturckow, will then fire its hybrid rocket motor for a planned duration of about 50 seconds or so, longer than any previous powered flight by this vehicle or the original SpaceShipOne, VSS Enterprise. The actual duration will depend on the performance of the vehicle and flight conditions, and company officials said the pilots will have some discretion on when to shut down the motor.
The key variable of the flight is not the burn time but the maximum altitude. “The real limitation we’re shooting for is an altitude,†said Mike Moses, president of Virgin Galactic, in a briefing with reporters here Dec. 12. “The time it takes to get to that altitude is variable, based on the trajectory that the pilot flies.â€
That altitude goal is approximately 80 kilometers, or 50 miles. “I think what we’ll see is something not far over 50 [miles],†said George Whitesides, chief executive of Virgin Galactic, if the flight goes as expected. The company has identified 50 miles as the altitude for reaching space, as NASA and the U.S. Air Force award astronaut wings to those who exceed that altitude.
More:
https://spacenews.com/virgin-galactic-ready-for-milestone-spaceshiptwo-flight/