Key Points:
- NASA delays Boeing Starliner’s return from ISS for technical reviews, with no new date set.
- Initially scheduled for June 26, the mission faces scrutiny over multiple technical issues.
- Starliner encountered five thruster failures, five helium leaks, and a slow-moving propellant valve.
- Boeing’s Starliner program faces $1.5 billion in cost overruns and ongoing technical challenges.
NASA has announced an additional delay for Boeing’s Starliner spacecraft’s return from the International Space Station (ISS), citing the need for more time to address technical issues. The Starliner’s return, initially set for June 26 and previously postponed from June 14, now remains unscheduled, raising uncertainties about the timing of the first crewed mission’s completion.
“Mission managers are evaluating future return opportunities following the station’s two planned spacewalks on June 24 and July 2,” NASA stated. The U.S. astronauts aboard the Starliner, Butch Wilmore, and Suni Williams, embarked on their journey on June 5 as part of a final demonstration to secure routine flight certification from NASA.
Steve Stich, NASA’s commercial crew program manager, emphasized the importance of thoroughness. “We are taking our time and following our standard mission management team process,” Stich said. He assured that the Starliner is performing well while docked at the ISS, and the extended timeframe will provide “valuable insight” into system upgrades for future missions.
The crewed test of the Starliner, which had previously been launched into space twice without humans since 2019, has encountered multiple issues. These include five failures of its 28 maneuvering thrusters, five helium leaks intended to pressurize the thrusters, and a slow-moving propellant valve indicating unresolved past problems. These complications have led to additional scrutiny and testing by NASA and Boeing, casting doubt on when the Starliner crew will be able to undertake the roughly six-hour return journey.
Boeing’s Starliner program, facing $1.5 billion in cost overruns beyond its $4.5 billion NASA development contract, has struggled with software glitches, design problems, and subcontractor disputes for years. NASA aims for the Starliner to join SpaceX’s Crew Dragon as a reliable U.S. spacecraft for ferrying astronauts to the ISS, but persistent issues have hindered progress.
Upon approaching the ISS for docking on June 6, the Starliner’s thruster failures temporarily halted the operation until Boeing implemented a fix. It involved rewriting software and adjusting procedures to restore functionality to four affected thrusters, allowing the docking to proceed.
The Starliner’s undocking and return to Earth represent the most complex phases of its test mission. NASA officials have expressed a desire to thoroughly understand the causes of the thruster failures, valve issues, and helium leaks before proceeding with the return. Despite resolving most issues, one thruster remains nonfunctional in the current flight. During the capsule’s uncrewed return from space in 2022, four thrusters also experienced problems.
Boeing and NASA’s flight rules mandate that the Starliner’s maneuvering thrusters must provide “six degrees of freedom of control,” with each thruster having a backup. A NASA spokesperson confirmed that at least 12 of the 28 thrusters, primarily backups, are essential for a safe flight.
