Boeing’s new Starliner capsule went off course on Friday during its first test flight, spoiling a crucial dress rehearsal for launching astronauts next year. The capsule will stay in orbit for a few days but won’t dock with the International Space Station as planned.

It will return to Earth as early as Sunday, landing in the New Mexico dessert, NASA and company officials said. They said the capsule was stable and safe.

Friday’s blastoff from Cape Canaveral, Florida, went flawlessly as the Atlas V rocket lifted off with the Starliner capsule just before sunrise. But a half-hour into the flight, Boeing reported that the capsule didn’t get into the right orbit. Officials said the spacecraft’s timer didn’t work properly and it burned up too much fuel to safely make the trip to the space station.

This was Boeing’s chance to catch up with SpaceX, NASA’s other commercial crew provider that successfully completed a similar demonstration last March. SpaceX has one last hurdle — a launch abort test — before carrying two NASA astronauts in its Dragon capsule, possibly by spring.

A successful Starliner demo could have seen Boeing launching astronauts by summer. But that might not be possible now. At a briefing, NASA Administrator Jim Bridenstine said it was too early to know if another test flight would be needed before flying astronauts.

“I’m not ruling it out,” Bridenstine said on whether the next Starliner might carry crew or go empty.Had astronauts been on board, they may have been able to take over, correct the problem, and get the capsule to the space station, he said.

It’s been nearly nine years since NASA astronauts have launched from the U.S. The last time was July 8, 2011, when Atlantis — now on display at Kennedy Space Center — made the final space shuttle flight.

Since then, NASA astronauts have traveled to and from the space station via Kazakhstan, courtesy of the Russian Space Agency. The Soyuz rides have cost NASA up to $86 million apiece.

The space agency handed over station deliveries to private businesses, first cargo and then crews, in order to focus on getting astronauts back to the moon and on to Mars.

Commercial cargo ships took flight in 2012, starting with SpaceX. Crew capsules were more complicated to design and build, and parachute and other technical problems pushed the first launches from 2017 to now next year. Last April, a SpaceX crew capsule exploded during a ground test.

Associated Press