Virgin Galactic has made a giant leap in the race to get tourists to space.

Richard Branson's space tourism venture was awarded an operating license from the FAA for its SpaceShipTwo aircraft Monday, according to a company press release. The license means that whenever the spacecraft is ready on Virgin's end, it has the government's permission to fly.

The spacecraft can't carry passengers just yet, though--first it will have to conduct test flights to prove its ships are safe enough. This certification gives the company permission to make those test flights.

The release said the process took several years and was the result of an "in-depth review of the vehicle's system design, safety analysis, and flight trajectory analysis."

It isn't known yet when the test flights will begin. Virgin Galactic didn't respond to a request for comment before this article published.

Virgin Galactic is in a race with companies like XCOR Aerospace and Jeff Bezos's Blue Origin to get tourists high above the earth's surface. While many spaceships use rocket boosters to launch vertically, SpaceShipTwo attaches horizontally to a carrier aircraft that takes it to a height of about 50,000 feet, where it's released. The spaceship then ignites a rocket engine to travel about 68 miles above the Earth's surface--several miles above the height generally considered to be space. Passengers experience a few minutes of weightlessness before being brought back to earth.

The list of ticket buyers is long and star-studded: 700 people, including Leonardo DiCaprio, Lady Gaga, Katy Perry, and Tom Hanks have bought a ride for $250,000.

This is the second version of Virgin Galactic's SpaceShipTwo. The first broke up during flight in October 2014, after one of the pilots shifted the angle of the spacecraft's wings too early. That pilot was killed and the other was injured in the crash. Virgin Galactic says it has since added an inhibitor to prevent the wings from being adjusted prematurely.