Virgin Galactic, one of the companies aiming to become the first to send astronauts into space, is planning to put its SpaceShipTwo vehicle through its next phase of testing starting as early as Thursday, December 13. It will be the fourth powered flight for the vehicle, named VSS Unity, and the first since its successful July 26 flight, which reached a peak altitude of 32 miles (52 kilometers).

Now, the company is aiming higher, further, and faster — this next round of tests will “[expan