ISS

Starliner’s Return Home is on The Horizon

Butch Wilmore and Suni Williams
Starliner’s crew, Butch Wilmore and Suni Williams, inside the vestibule between the ISS and Starliner. Image: NASA

The astronauts who headed to the ISS aboard Starliner over a month ago for a week-long mission finally have a hopeful return-by date to look forward to, NASA and Boeing officials said Wednesday.

The reason: They’re parked in someone else’s spot.

SpaceX’s Crew-9 is expected to replace Crew-8 on the ISS in a direct-handover in August, and to do so, Starliner will need to move.

What’s the hold up: Engineers at NASA’s White Sands, NM test facility have been trying to recreate the conditions that led to a few of Starliner’s thrusters failing in its approach to the ISS. They are expected to wrap up these tests by next week, according to Steve Stich, program manager for NASA’s commercial crew program.

While they haven’t yet recreated the exact flight conditions on the ground, in part due to delays brought on by Hurricane Beryl, engineers believe that the source of the thruster failures may lie in the thermos-like atmosphere created by Starliner’s “doghouse” thruster housing.

Additional maneuvers beyond previous uncrewed flight tests also may have overheated the propulsion system to the point of failure, which drove Butch Wilmore to take manual control of the spacecraft for over an hour before switching back to automated docking with the ISS.

“You could tell that the thrust, the control, [and] the capability was degraded,” Wilmore told reporters.

Because this was a test flight, NASA and Boeing want to gather as much data as possible before they give Starliner the green light to return home. At the outset of their time on the ISS, the crew’s stay was limited by the 45-day lifespan of Starliner’s batteries, but engineers now believe that the risks of remaining in orbit longer are minimal.

Happy to be here: Boeing and NASA also stress that, if needed, Starliner can return to Earth at any time. The spacecraft can return home safely even with degraded thrusters, and the crew already took to Starliner as a safe-haven—ready to make like a tree—when a defunct Russian satellite broke up in LEO last month.

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