Boeing just can’t seem to catch a break these days. What was supposed to be a short week-long test flight of their Starliner capsule system for delivering astronauts to and from the International Space Station has now left Butch Wilmore and Suni Williams stranded at the ISS for three weeks, and wondering if they might have to catch a ride with Space X’s Crew Dragon at some point if the issues plaguing Boeing’s Starliner can’t be resolved in the meantime. From the AP:
Why was the Starliner return trip postponed?
NASA wants more time to analyze problems in the spacecraft's propulsion system, which is used to maneuver in flight. The propulsion system is attached to the capsule, but it doesn’t come back to Earth for inspection. It is ditched during reentry and burns up.
“We’re just taking a little more extra time to review all the data and also learn as much as we can while we have this service module in orbit," Steve Stich, NASA’s commercial crew program manager, said at a news conference last week before the latest postponement.
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What are the problems being investigated?
Five of the capsule’s 28 thrusters went down during docking, as the capsule closed in on the space station. All but one thruster was restarted, and they worked during a later test firing, NASA said. Officials suspect that heat from all the thruster action at docking caused the shutdown. The one faulty thruster has been turned off and is not an issue for the return trip, Boeing said.
The capsule launched June 5 with one small helium leak, but four more leaks sprung up by the time it reached the space station. Helium is used to pressurize fuel for the thrusters, and a faulty rubber seal was suspected in the initial leak. Officials say there's an amply supply of helium, and Boeing says the leaks are stable and not a concern.
Reuters and Chron (the Houston Chronical?) have additional details on Starliner’s problems as well:
Even with the propulsion system issues, NASA has said Starliner still would be capable of returning the astronauts to Earth if absolutely necessary - that is, if the capsule must serve as an escape pod from the ISS in an emergency or if any of Starliner's perishable items - such as its solar panels - show signs of expiring earlier than planned.