Virgin Galactic’s new commercial spaceship, the VSS Unity, made its first test flight Thursday near Mojave, California. It had been nearly two years since a fatal crash left the SpaceShipTwo model earthbound for rebuilding and safety improvements.

The move came as a surprise, just one day after the company made a vague announcement to begin testing “in the near future.”

For its first flight, the Unity stayed mated to a WhiteKnightTwo carrier ship. The paired couple taxied on ground for a while before officials granted clearance for takeoff. Two pilots commanded each vessel, for a total of four crew on board.

It’s the first test flight for SpaceShipTwo since October 2014, when the VSS Enterprise crashed back to Earth, killing one of two crew members on board. The co-pilot had prematurely deployed the craft’s feathered drag system, although the National Transportation Safety Board found that a better design should have eliminated the possibility of that sort of human error. The Enterprise had completed 54 successful flights before it met its untimely end.

Since then, Virgin Galactic has been hard at work on the Unity, improving safety and automation systems. After two years of on-ground building and testing, the craft is finally airworthy. When engineers are satisfied with the craft’s performance in mated flights, it will progress to gliding back to Earth solo, and finally to rocket-powered ascents.

Assuming Unity passes these tests with flying colors, it will one day take wealthy tourists on $250,000 tours of Earth’s thermosphere, more than 50 miles up.

Photos via Virgin Galactic