The launch of Boeing’s crewed Starliner space capsule is called off yet again

A launch of Boeing's Starliner space capsule was scrubbed on Saturday just minutes ahead of its scheduled liftoff time.

With 3:50 left in the countdown, the rocket’s computer initiated a hold. The next launch attempt won’t happen until at least Wednesday, NASA said.

An issue with one of the three redundant computer systems at the base of the launch pad that are responsible for initiating the launch sequence prompted the automatic halt, said Tory Bruno, the head of United Launch Alliance, the government contractor trying to launch the Starliner.

“We do require all three systems to be running — triple redundancy,” ULA President and CEO Bruno said at a Saturday afternoon press briefing. “Those three big computers do a health check. … Two came up normally. The third one came up, but it was slow to come up, and that tripped a red line that created an automatic hold."

ULA engineers don’t know why the computer halted, and will troubleshoot ground support equipment overnight, NASA said in an update on Saturday evening.

NASA had been aiming to reschedule the planned launch for a day later, but said it would forgo the launch attempt on Sunday, “to give the team additional time to assess a ground support equipment issue.”

The next launch attempt opportunity is on Wednesday and Thursday.

The space agency said it would provide an update on Sunday about next steps.

The space capsule was scheduled to carry two NASA astronauts from Cape Canaveral Space Force Station in Florida on a 25-hour flight to the International Space Station. The planned mission is the first time the commercially built capsule will carry humans.

NASA astronauts Butch Wilmore and Suni Williams were planning to take Starliner on its maiden flight, putting the vehicle through its paces ahead of operational missions for NASA. After the Space Shuttle retired in 2011, NASA partnered with two commercial companies -- Boeing and SpaceX -- to ferry astronauts to and from the space station.

Saturday's scrub comes roughly a month after the Starliner was originally supposed to fly to the station, and that launch was already years behind schedule.

Earlier, in a twist familiar to many air travelers here on Earth, NASA announced that the astronauts' luggage was getting left behind. The lost luggage isn’t Boeing’s fault. The space station’s urine recycling system broke earlier this week and NASA had to make room to send up a new pump.

“We ended up pulling off two crew suitcases, those have clothes on them,” said Dana Weigel, the manager of NASA’s International Space Station Program, during a press briefing on Friday.

Weigel said there's spare clothes and hygiene items aboard the space station, which the crew could use during their stay.

Here’s what else to know about the now-scrubbed launch.

This was supposed to be the first flight of the Starliner with humans aboard

In 2014, NASA awarded Boeing a $4.2-billion-dollar contract to build Starliner as a vehicle to carry astronauts on routine missions to the International Space Station.

The Starliner program has since fallen far behind schedule and gone over budget. Boeing has estimated the program has cost the company over $1 billion in losses.

At the same time NASA awarded the Boeing contract, it gave SpaceX $2.6 billion to develop its Dragon capsule. That spacecraft conducted its crewed test flight in 2020, and now regularly carries astronauts to the station.

Starliner has been beset by technical problems

Saturday's scrubbed launch is not the first delay for the Starliner program.

The Starliner failed to reach the I.S.S. during its first mission in 2019. The cause was an incorrectly set onboard clock, which caused a computer to fire the capsule's engines too early. The spacecraft managed to reach the I.S.S. during its second test flight in 2022, despite the failure of some thrusters to work as planned.

Boeing delayed Starliner's first crewed flight last year, after company officials realized that adhesive tape used on hundreds of yards of wiring was potentially flammable, and the capsule’s three parachutes were connected with lines that appeared to be weaker than expected.

Its launch attempt on May 6 was called off due to a stuck valve on the rocket launching Starliner. That valve was replaced, but engineers also discovered a small helium leak in one of Starliner’s thrusters.

The leak is probably due to a faulty seal, though the engineers aren’t totally sure. Still, after weeks of extensive analysis they said that Starliner could fly safely even with the leak.

The future of the Starliner

If Starliner is able to eventually launch successfully, it will pave the way for more Starliner flights, which will give NASA two independent private spacecraft that can carry astronauts to the space station.

On their mission, Wilmore and Williams were planning to test key systems of Starliner as it docks with the space station, including life support and communication. While the spacecraft can essentially fly itself, the duo were to test out manual controls of the vehicle as it approached the orbiting outpost.

The crew had planned to spend about a week on the station with a scheduled landing under a canopy of parachutes as early as June 10 in Willcox, Ariz. -- capping off a 10 day mission. Teams at NASA and Boeing were to comb through the data from this flight before certifying the vehicle for operational missions. NASA hopes to split astronaut flights between Boeing and SpaceX, with trips to the ISS happening about every six months.

NPR's Joe Hernandez and Emma Bowman contributed to this report.