Boeing Starliner departure from space station remains delayed due to 'complicated' issues

Boeing Starliner's first astronaut crew will spend an additional week in orbit as ground teams complete more data reviews of ongoing issues with the spacecraft.

Starliner launched NASA astronauts Suni Williams and Butch Wilmore on June 5 from Cape Canaveral, Florida, on a United Launch Alliance Atlas V rocket. The pair is conducting the Crew Flight Test of Boeing's Starliner spacecraft to certify the vehicle to fly crew as part of NASA's Commercial Crew Program. SpaceX's Crew Dragon vehicle also flies astronauts as part of the NASA program and is preparing for its ninth NASA astronaut mission this summer. 


After arriving at the International Space Station on June 6, Williams and Wilmore were expected to spend about eight days on the orbiting laboratory. However, issues with Starliner's hardware prompted NASA managers to delay their return date several times.

The latest delay was announced Tuesday when NASA Commercial Crew Program Manager Steve Stich said Starliner's new target return is no earlier than 10:10 p.m. ET on June 25. 

"We want to give our teams a little bit more time to look at the data and make sure we will be ready to come home," Stich said. 

If Starliner undocks from the ISS, it will land in White Sands Space Harbor in New Mexico on June 26 at 4:51 a.m. ET. Undocking and landing attempt opportunities occur every four days. 

Despite extending their mission more than twice the original timeline, the astronauts are in good spirits.

"They've been very positive about the whole thing," Stich said. "They love Starliner. They love being in the vehicle. They love being on the ISS. I think, you know, if you ask Butch and Suni, they might want to stay for a long period."

Stich said NASA and Boeing teams took this past weekend off because they had been working hard on the Starliner issues and needed a break.

"What's really complicated is, you know, we're going through all the data from this flight, but comparing it to OFT-2 and also looking forward to the remainder of the flight and running simulations," Sitch said, referring to the second orbital flight test and Starliner's first visit to the ISS without crew in 2022. 

Path forward to Starliner's landing

Over the weekend, teams completed a hot fire of the Starliner spacecraft's thrusters with the vehicle docked at the ISS to troubleshoot the issues encountered during docking when five thrusters failed. 

Stich said the best place to test these issues is in orbit because they can replicate the thermal conditions on Starliner exactly, unlike simulations on Earth. The thruster issue is limited to the spacecraft's service module, which does not return to Earth with the crew module. 

When it returns to Earth, Starliner will face two big milestones that require the thrusters to orient the vehicle for landing. Teams are working to understand how the thrusters will perform during the deorbit burn.

NASA and Boeing's engineers continue to analyze five helium leaks discovered between the launch and docking. Stich said NASA's Marshall Space Flight Center teams are doing field testing to simulate the leak rates.

The spacecraft needs 7 hours of helium and has 70 hours of margin to reach the deorbit burn. 

"The path going forward is to continue to look at the helium system, continue to try to understand what's happening, again, look at simulations for the remainder of the flight," Sitch said. "What's our demand? What if we wave off? And what does that mean for the system?"

If Starliner misses the June 26 landing opportunity, another attempt is available on June 30. Teams will also monitor the weather in the Southwest desert before giving the go-ahead for undocking.