Virgin Galactic now has a commercial operating license for its SpaceShipTwo vehicle. That’s the company’s spaceplane that’s designed to take passengers into sub-orbital space. The license, granted by the Federal Aviation Administration, allows Virgin Galactic to begin conducting test flights of the vehicle to see if it’s capable of carrying paying customers safely above Earth. However, the company has yet to announce when those first test flights will take place.

"When we feel ready to start flying, we can start flying."

"We've still got a bit more work to do before [SpaceShipTwo] takes to the skies, but this effectively means that when we feel ready to start flying, we can start flying," said Will Pomerantz, vice president for special projects at Virgin Galactic. "The key permissions are in place."

However, there are some limits on what Virgin Galactic can fly on SpaceShipTwo. The license only authorizes the company to fly "non-deployed scientific, experimental, or inert payloads" onboard the spaceplane. Virgin Galactic is restricted from carrying passengers aboard SpaceShipTwo until the company can successfully show the FAA that the vehicle's hardware and software work properly during flight tests.

Though SpaceShipTwo is designed to reach sub-orbital space, it doesn’t launch vertically like most rocket-powered spacecraft do these days. To get to space, the plane is carried to a certain altitude by its four-engine carrier aircraft, WhiteKnightTwo. Once there, the spaceplane is released and ignites its rocket engine, climbing up to 68 miles above the Earth’s surface. After lingering at the edge of space for a few minutes — where "space tourists" will be able to experience weightlessness — SpaceShipTwo shifts the positions of its wings to safely reenter Earth’s atmosphere and glide back down to a runway.

WhiteKnightTwo carrying the first SpaceShipTwo. (Virgin Galactic)

The SpaceShipTwo that Virgin Galactic currently owns has yet to fly, though. But the company did announce that it has started testing the spacecraft outside of its storage hangar at the Mojave Air and Space Port in California. Virgin has conducted the first "taxi test" of SpaceShipTwo, in which a Range Rover Autobiography pulled the spaceplane outside. The test was meant to see if SpaceShipTwo’s navigation and communication systems were working properly.

The SpaceShipTwo that Virgin Galactic currently owns has yet to fly

This is actually Virgin Galactic's second SpaceShipTwo. The first version was destroyed during a powered test flight on Halloween of 2014; a mistake by one of the two pilots caused the wings to shift too early, which made the vehicle break apart. The crash killed one pilot and injured the other.

Prior to the accident, Virgin had already been developing the current SpaceShipTwo, which is nearly identical to the first. The company rolled out the second vehicle in February at an unveiling ceremony, where it was renamed VSS Unity by famed astrophysicist Stephen Hawking. The spaceplane now serves as a replacement for the first vehicle that was lost, though it has a few design modifications meant to prevent similar accidents in the future, according to the company.

So far, a lot of people have signed up to ride into space on the VSS Unity — mostly those with a lot of cash to burn. One ticket on the spaceplane costs $250,000, a price that many celebrities, such as Katy Perry, Justin Bieber, and Ashton Kutcher, have already paid for. Virgin Galactic said that it did lose a few customers after the accident, but that its numbers have recovered since then.

Update August 2nd 8:30AM ET: This article was updated to include information about the license's restrictions.