NASA postpones Boeing Starliner's return from ISS citing technical issues
NASA has officially announced a delay in the return of Boeing's Starliner spacecraft from the International Space Station (ISS). The spacecraft, which was initially scheduled to return on June 26, is now postponed due to technical issues and additional testing requirements. The crew onboard includes US astronauts Butch Wilmore and Sunita Williams who embarked on June 5 for a final demonstration flight aimed at obtaining routine flight certification from NASA.
Starliner faces challenges, raises questions about return
The Starliner spacecraft has faced several challenges during its test flight, including five failures of its 28 maneuvering thrusters and five helium leaks intended to pressurize those thrusters. Additionally, a slow-moving propellant valve signaled unresolved issues. These problems have raised questions about when the crew will be able to return home and have added to Boeing's broader issues with the Starliner program, which has already seen $1.5 billion in cost overruns in addition to the $4.5 billion NASA development contract.
Starliner's struggles and NASA's aspirations
Boeing's Starliner program has been grappling with software glitches, design problems, and subcontractor disputes for years. Despite these challenges, NASA aims for Starliner to become the second US spacecraft capable of ferrying astronauts to and from the ISS, alongside SpaceX's Crew Dragon. The latter has been NASA's primary ride since 2020. When Starliner attempted to dock at the space station on June 6, thruster failures prevented a close approach until Boeing implemented a fix.
Understanding Starliner's technical issues before return
Starliner's undocking and return to Earth represent the most complex phases of its test mission. NASA officials have expressed a desire to better understand the cause of the thruster failures, valve issue, and helium leaks before Starliner embarks on its roughly six-hour return journey. Despite reviving four thrusters during this flight, Boeing previously encountered four thruster problems during the capsule's uncrewed return from space in 2022.
Flight rules for Starliner's safe journey
According to flight rules jointly established by Boeing and NASA, Starliner's maneuvering thrusters must allow for "6-degrees of freedom of control," with each thruster having one backup. This implies that at least 12 out of the 28 thrusters - most of which are backups - are required for a safe flight. However, potentially fewer could suffice as long as the remaining thrusters have one backup and can work together without restricting Starliner's freedom of movement in space.
