New York: Boeing Co.’s CST100-Starliner will return to Earth six days ahead of schedule and with “something to prove” after its failed mission to hook up with the International Space Station, said Jim Chilton, senior vice-president of Boeing’s space unit.

The craft is set to land Sunday at 5:57am Mountain Time (7:57am. Eastern) at the White Sands Space Harbor in New Mexico, with a 1:48pm MST backup time if needed. The unmanned spacecraft took off Friday morning aboard an Atlas V rocket near Cape Canaveral, Florida. It soon ran into problems that resulted in the vessel entering orbit off course — and raised further questions about Boeing’s engineering prowess.

Boeing diagnosed the problem as a “data-retrieval” software issue that collected the wrong mission time. By the time the Starliner received the correct time, it was too late to continue to the space station because fuel was in danger of running low.

“We don’t have the prop to rendezvous, so we’re going to come on home,” Chilton said in a joint press conference with Nasa. “So far, it doesn’t look like a major systemic issue,” he said, adding that the Starliner’s status is “really excellent.”

In addition to denting Boeing’s prestige, the setback is a blow to US plans for human flights as soon as next year — the company has been hired to carry crew to the ISS as part of NASA’s commercial crew program.

According to Steve Stich, deputy manager for the National Aeronautics and Space Administration’s commercial crew program, the mission could have been a success with humans on board.

“The crew would have noticed that the guidance mode was in the wrong mode and flown the spacecraft manually,” he said. There’s a test dummy “Rosie The Rocketeer” on board to show how a human might do on such a mission.

As for whether the timing problem could have been detected before take-off, Stich said he’s “not aware of anywhere that is was displayed.”

“Tomorrow is a really big day,” Nasa Administrator Jim Bridenstine said. “People want to know what per cent of the test objectives have been completed, but not all objectives are weighted equally.” Simply landing the capsule successfully represents a significant challenge.