Virgin Galactic successfully completed a second test flight of its SpaceShipTwo space plane from the company's New Mexico spaceport on Thursday (June 25), bringing the company one step closer to its goal of providing private spaceflights for paying customers. 

The suborbital space plane, called the VSS Unity, glided down to Spaceport America from an altitude of 51,000 feet (15,500 meters), where it was released from its WhiteKnightTwo carrier plane, called VMS Eve. On board the VSS Unity were two pilots, Mark ‘Forger’ Stucky and Michael 'Sooch' Masucci, who are both commercial astronauts. Piloting the VMS Eve were Nicola Pecile and CJ Sturckow.

While Virgin Galactic has completed several unpowered glide test flights of the VSS Unity before, this is only the second time that the test happened at Spaceport America. The VSS Unity's first flight from Spaceport America was on May 1; previous flights took off from Mojave Air and Space Port in southeastern California.

"This glide flight, flown at higher speeds, allowed the team to continue to evaluate systems and vehicle performance in advance of future rocket-powered space flights from the company’s new operating base in New Mexico," Virgin Galactic said in a statement. 

"Flying VSS Unity in glide configuration at higher speeds enables certain vehicle systems to operate close to the environment seen during phases of rocket boost on a spaceflight."

During the flight, the VSS Unity reached a glide speed of Mach 0.85 after it was released from the mothership, and the pilots executed a series of maneuvers "to gather data about performance and handling qualities while flying at higher speeds," Virgin Galactic said. "This data will be verified against similar maneuvers that were performed in the previous glide flight to enhance aerodynamic modelling."

Virgin Galactic is currently selling tickets for commercial flight on board SpaceShipTwo for $250,000, and the company has sold more than 600 tickets. It is not clear exactly when the first commercial flights will begin. The company has said that flights could begin as early as this year.