Virgin Galactic’s SpaceShipTwo is grounded until the Federal Aviation Administration completes and signs off on an investigation into the company’s high-profile test flight carrying Richard Branson, the agency said Thursday.

During that July flight, Virgin Galactic’s SpaceShipTwo veered out of its approved airspace on its descent toward land, the FAA said.

The company “may not return the SpaceShipTwo vehicle to flight until the FAA approves the final mishap investigation report or determines the issues related to the mishap do not affect public safety,” an FAA spokesperson said on Thursday.

SpaceShipTwo, a winged suborbital space tourism plane that launches to the edge of space from a carrier aircraft, landed its crew of Branson and three company employees safely. But it wasn’t until this week — nearly two months later — that the public learned the mission wasn’t as successful as the company made it out to be.

A New Yorker story published on Wednesday first revealed the FAA investigation and found that the two pilots for Unity 22, the formal name for the mission, had been alerted to yellow and red warning lights during the ship’s rocket-powered ascent to space.

Those lights, The New Yorker reported, indicated the spaceship wasn’t ascending vertically enough to be able to free-glide back with enough momentum to land after reaching space. As the spaceship was returning, it veered out of its Air Traffic Control airspace, prompting an FAA investigation.

“We take this seriously and are currently addressing the causes of the issue and determining how to prevent this from occurring on future missions,” a Virgin Galactic spokesperson said in a statement on Thursday, reiterating that the crew was never in any danger during the flight.

“We have been working closely with the FAA to support a thorough review and timely resolution of this issue.”

Virgin Galactic, a publicly traded space tourism company that billionaire Richard Branson founded in 2004, said late Wednesday that the FAA probe “has no impact on future test flights,” even as the probe remains active.

FAA investigations into unexpected in-flight events, like Virgin Galactic’s, keep future flights grounded until the agency’s inquiry is complete and any potential corrections are made by the company.

Virgin Galactic didn’t respond to a request for clarification on how it concluded the incomplete probe wouldn’t impact its next test flight, Unity 23, which is slated for sometime in the next month.

That flight will carry three members of the Italian Air Force as the company’s first revenue-generating mission.