Starliner Astronauts Will Remain on Space Station Until July Amid Technical Issues

NASA and Boeing have delayed the crewed mission’s return to Earth again, as engineers assess helium leaks and a thruster issue on the spacecraft’s service module

An illustration of the Boeing CST-100 Starliner spacecraft, currently docked to the International Space Station as engineers troubleshoot thruster and helium leak issues.
An illustration of the Boeing CST-100 Starliner spacecraft, currently docked to the International Space Station as engineers troubleshoot helium leaks and thruster issues. NASA / Boeing

In what has already been an imperfect summer for NASA’s Boeing Starliner, the capsule has experienced another snafu in its first-ever crewed mission to the International Space Station (ISS). Due to helium leaks and thruster issues, the return of U.S. astronauts Butch Wilmore and Suni Williams, who traveled to the station on Starliner this month, has been delayed until July.

“We want to give our teams a little bit more time to look at the data, do some analysis and make sure we’re really ready to come home,” Steve Stich, manager of NASA’s Commercial Crew Program, said during a news conference last week.

For the time being, Starliner will remain docked to the ISS, where Wilmore and Williams—both former U.S. Navy test pilots who together share 11,000 flight hours—could spend up to 45 days, if need be, as they await the go-ahead for their return.

Officials stressed that the astronauts are not stranded on the station—the Starliner vehicle can still be used for evacuation in the event of an emergency. But NASA aims to complete a formal review to gauge the spacecraft’s readiness for re-entry before it transports humans back to Earth.

The delay also prevents Starliner’s undocking from conflicting with spacewalks planned for June 24 and July 2, per a statement from Boeing.

Butch Wilmore and Suni Williams, the Starliner crew, pose here with a T-38.
Butch Wilmore and Suni Williams, the Starliner crew, pose here with a T-38. NASA / Robert Markowitz

This delay is the latest mishap in a mission that got off to an uncertain start. Starliner, which is currently running years behind schedule, launched on uncrewed test flights in 2019 and 2022, each of which revealed technical issues, per CNN’s Jackie Wattles.

Originally slated for May 6, Starliner’s first crewed liftoff was scrubbed just two hours prior to launch when engineers noted a faulty valve on the Atlas V rocket, on which the capsule was mounted. Then delayed to May 17, the mission fell further behind when engineers discovered a small helium leak, pushing the launch again to June 1.

This extra time allowed the teams to assess the situation, and they cleared the mission to fly despite the leak.

“Sometimes, for spaceflight, you plan for contingencies, and you design the vehicle to have margin,” Stich said during a press briefing before the June 1 flight attempt, Space.com’s Elizabeth Howell and Josh Dinner reported. “We have margin in the helium tank… we could handle a leak that’s 100 times worse than this. We concluded that the smartest thing to do was to go fly the mission, and we could fly it safely.”

But minutes before the planned takeoff, crews identified a power issue with the ground equipment, delaying the flight once more. Finally, on June 5, the capsule nicknamed Calypso was launched into space.

“We all know that when the going gets tough, as it often does, the tough get going, and you all have,” Wilmore said of the mission’s teams prior to liftoff, per the BBC’s Jonathan Amos.

“Go Calypso!” Williams added. “Take us to space and back.”

The CST-100 Starliner spacecraft, photographed in 2019 during launch preparations.
The CST-100 Starliner spacecraft, photographed in 2019 during launch preparations. NASA / Boeing

During Starliner’s 25-hour flight to the space station, engineers identified four additional helium leaks and problems with five of the 28 thrusters, all in equipment located on the service module. Nonetheless, the spacecraft and its two passengers safely docked to the ISS.

Since then, issues with four of the thrusters appear to have resolved, but the astronauts’ return date has been pushed back repeatedly and is now scheduled for no earlier than July 2.

“We’ve learned that our helium system is not performing as designed,” Mark Nappi, Boeing’s Starliner program manager, said at the news conference last week, per Live Science’s Ben Turner. “Albeit manageable, it’s still not working like we designed it. So we’ve got to go figure that out.”

Upon re-entry to Earth’s atmosphere, the capsule’s service module will be discarded and burn up—meaning engineers won’t be able to physically inspect it afterward. As such, NASA and Boeing want as much time as possible to study the module, diagnose and rectify these issues, both for this upcoming flight and future planned missions. Currently, Starliner-1, the spacecraft’s first operational flight, is slated for 2025.

In the meantime, officials say astronauts Wilmore and Williams are doing well aboard the ISS and helping in a variety of tasks and missions.

And even though the craft has several helium leaks, “only seven hours of helium is needed for the return to Earth, and the Starliner has more than ten times that amount left on board,” writes CBS News William Harwood.

“So far, we don’t see any scenario where Starliner is not going to be able to bring Butch and Suni home,” Stich said at the news conference, per CNN.

Get the latest stories in your inbox every weekday.