The next test flight of Virgin Galactic’s SpaceShipTwo suborbital spaceplane is set for December 13th. This flight could be the first by SpaceShipTwo to reach at least one definition of space.
In a statement issued on December 11th, the company explained that the next powered test flight of VSS Unity, the second SpaceShipTwo, is slated for a window that opens December 13th from the Mojave Air and Space Port in California.
The flight would be the fourth powered flight for this spacecraft and the first since July. The statement came shortly after the publication of airspace restrictions in the vicinity of the airport for the rocket launch and recovery for December 13th through the 15th.
In their statement, Virgin Galactic said that at a basic level, this flight’s goal is to fly higher and faster. They plan to burn the rocket motor for longer than they ever have in flight before, but not to its full duration.
The flight will gather new and vital data points about the spacecraft at higher altitudes and speeds, such as supersonic handling qualities and thermal dynamics. How long they burn, the rocket motor will be determined by how well the vehicle is doing, according to the company statement. On the previous flight, SpaceShipTwo’s hybrid rocket motor burned for 42 seconds, while a full-duration burn would run for approximately 60 seconds.
On their previous flight, SpaceShipTwo reached a peak altitude of 52 kilometres, and the company suggested the vehicle could go much higher on this second flight.
If all goes well, the vehicle could fly high enough to reach space, however, that depends on the definition of space. Virgin Galactic stated that they also plan to burn the rocket motor for durations which will see their pilots and spaceship reach a space altitude for the first time. However, the company noted that, based on the outcome of this flight, it might take them a little longer to reach that milestone.
The statement didn’t go into detail about what Virgin Galactic meant by space altitude, but company officials have previously stated they were using the altitude of 50 miles, or about 80 kilometres, used by NASA and the U.S. Air Force for awarding astronaut wings.
Of course, that is below the 100-kilometre Karman Line often used as the boundary of space, including in the Ansari X Prize competition won by SpaceShipOne in 2004. Nevertheless, the Fédération Aéronautique Internationale (FAI), the world air sports federation that keeps records for both aviation and spaceflight, announced on November 30th that it would reconsider that definition and perhaps lower it.
The company added that, on this test flight, it is carrying four unnamed payloads through NASA’s Flight Opportunities program, which offers suborbital and related flights of research payloads. Virgin Galactic explained that those experiments are part of an initiative by the company to begin simulating the commercial weight distribution in the spaceship represented by their eventual passengers.