Boeing Co., already reeling from the nine-month grounding of its best-selling jetliner, suffered another high-profile setback when its CST-100 Starliner crew capsule failed to reach the International Space Station on its debut test flight.

An erroneous timer prompted the unmanned Starliner to make out-of-sequence flight adjustments that burned too much fuel after the capsule reached orbit, Boeing and the National Aeronautics and Space Administration told reporters Friday. The vehicle is expected to return to Earth for a parachute landing at White Sands Missile Range in New Mexico early on Dec. 22.

The mishap jeopardizes U.S. plans for human flights as soon as next year by Boeing, which was hired to ferry astronauts to the ISS as part of NASA‘s commercial crew program along with Elon Musk’s Space Exploration Technologies Corp. Boeing’s failure also deepens the sense of crisis around the aerospace giant as it tries to persuade regulators to end a flying ban on its 737 Max after two deadly crashes.

Boeing fell one per cent to US$330.04 at 10:40 a.m. in New York. The stock rose 3.4 per cent this year through Thursday while the S&P 500 advanced 28 per cent.

NASA and Boeing officials said they were still trying to understand the cause of the timer failure. It’s too soon to assess the impact on subsequent Boeing space flights, they said.

About 50 minutes after liftoff, the Starliner was out of position to begin its orbital insertion burn, the last boost into an orbit so the vehicle could dock at the space station. Had astronauts been on board, they might have been able to correct the problem, Bridenstine said.

The capsule took off aboard a United Launch Alliance Atlas V rocket at 6:36 a.m. near Cape Canaveral, Florida, Boeing and NASA said. The capsule separated and began flight on its own about 15 minutes later.

Starliner had been scheduled to rendezvous with the ISS early Saturday.

The test flight was the second mission to the space station for NASA’s commercial crew program, which is designed to end U.S. reliance on purchasing seats aboard Russia’s Soyuz spacecraft. The Russian rides have been the sole crew transport since the Space Shuttle was retired in 2011.

SpaceX conducted a demonstration flight of its Crew Dragon capsule to the ISS in March, also with no one aboard. Musk’s company and Boeing expect to fly astronauts for the first time next year.

NASA in 2014 awarded SpaceX and Boeing combined contracts valued at as much as US$6.8 billion to fly U.S. astronauts to the ISS. The agency chose two companies to assure safe, reliable and cost-effective access to space while avoiding the risks giving one provider a monopoly.

The space agency has declined to set dates on manned missions, pending the outcome of the Boeing test flight. The agency and SpaceX plan to perform an in-flight abort test of SpaceX’s Crew Dragon on Jan. 11 from Florida.