Test pilots Mark "Forger" Stucky and Michael "Sooch" Masucci ran the craft through a series of maneuvers over Mojave, California during which it reached a transonic velocity of Mach 0.9 (690 mph) – almost the highest it can attain without an engine.
The January 11 flight was the latest in a series of dry run flights for the Unity, which is the replacement prototype for the VSS Enterprise – the craft lost in a midair accident in 2014. Unity was carried aloft by the mothership VMS Eve before being dropped at high altitude to return to Earth on a glide path.
The purpose of the flight was to subject Unity to higher acceleration loads and forces, simulating the conditions of powered flight and pushing the craft's performance envelope. It was also a test for various modifications to the design that have been put through months of ground testing in the lead up to Thursday's flight.