When Suni Williams and Butch Wilmore packed for their trip to the International Space Station in early June 2024, they packed for approximately a week. The mission profile was eight to ten days. The clothes they brought, the personal items they brought, the level of mental preparation they brought were all calibrated to a trip about the length of a tropical vacation. Two hundred and eighty-six days later — having lived aboard the ISS for the better part of a year, having become full members of two consecutive Expedition crews, having watched their original spacecraft return to Earth without them in September because NASA had concluded it was no longer safe to ride home in — they finally landed in the Gulf of Mexico aboard a SpaceX capsule on 18 March 2025. The eight-day mission had, by then, become the longest single accidental extension of a human spaceflight in NASA history, and the most public engineering crisis the Boeing Commercial Crew Program had yet encountered.
According to Space.com’s coverage of the Starliner thruster crisis, the immediate problems began as Starliner approached the ISS for docking on 6 June 2024. Five of the capsule’s 28 maneuvering thrusters, mounted on the service module, began misfiring or shutting down entirely. Helium leaks were detected in the propulsion system manifolds. The docking was eventually completed, but the underlying questions about the vehicle’s ability to safely undock from the station and execute the precise series of deorbit burns required to bring the astronauts home became, in subsequent weeks, increasingly serious. The original plan had assumed Starliner would carry Williams and Wilmore back to Earth within ten days of arrival. By late July 2024, NASA and Boeing engineers were still trying to determine whether the propulsion problems could be safely characterised, much less corrected. The astronauts remained aboard the ISS while ground engineers ran simulations.
The decision
The formal decision came on 24 August 2024. Per NASA’s official announcement of the uncrewed-return decision, the agency concluded that bringing Williams and Wilmore home aboard Starliner posed risks it was not willing to accept. The specific failure mode that worried engineers most concerned Teflon seals inside the thrusters that appeared to be degrading and bulging when the thrusters fired at high temperatures — a problem that could not be fully characterised because the service module containing the affected thrusters was scheduled to burn up during atmospheric reentry, eliminating the possibility of post-flight inspection. The agency’s administrator at the time, Bill Nelson, summarised the rationale: “Spaceflight is risky, even at its safest and most routine. A test flight, by nature, is neither safe, nor routine.” Starliner would return to Earth uncrewed. Williams and Wilmore would be folded into the ISS’s regular crew rotation and would eventually come home aboard a SpaceX vehicle.
Starliner undocked from the ISS on 6 September 2024, executed its deorbit burn successfully, and landed at White Sands, New Mexico — without crew, without serious incident, and without resolving any of the underlying engineering questions about whether it could have safely brought Williams and Wilmore home if it had been required to. Three weeks later, on 28 September 2024, a SpaceX Crew Dragon capsule launched to the ISS carrying NASA astronaut Nick Hague and Russian cosmonaut Aleksandr Gorbunov. Two of the four seats were left intentionally empty, reserved for Williams and Wilmore’s eventual return. That return would not happen for another six months.
What the 286 days actually involved
The “stranded” framing that dominated media coverage of the situation became, over the subsequent months, a source of mild frustration for the astronauts themselves. Williams and Wilmore were not stranded in the literal sense. They were absorbed into the ISS’s standard crew rotation as members of Expedition 71 and then Expedition 72. They conducted scientific research. They performed maintenance on station systems. Williams became ISS commander in September 2024 and completed multiple spacewalks during her extended mission, including one that pushed her cumulative spacewalk time to a record for a female astronaut. Both Williams and Wilmore have repeatedly described their extended stay in terms that emphasise their professional engagement with the work rather than any sense of isolation or distress.
Williams’s total accumulated spaceflight time across her career, by the time of her March 2025 return, reached 608 days — the fourth-highest cumulative total of any NASA astronaut and the highest of any NASA woman. The 286-day mission itself sits comfortably within the range of routine modern ISS expeditions; Scott Kelly’s 340-day mission in 2015-2016 was longer, and Frank Rubio’s 371-day mission in 2022-2023 was longer still. The physiological recovery required upon return was substantial but within standard parameters for long-duration ISS missions. Bone density loss, muscle atrophy, cardiovascular deconditioning, and the cluster of vision-related changes documented in long-duration spaceflight all applied to both astronauts, but the rehabilitation protocols were well-established and the recovery proceeded along expected lines.
What the mission means for Boeing
The Starliner programme, by every available measure, is in substantial trouble. As reported by CNBC’s coverage of the March 2025 return, Boeing’s $4.2 billion Commercial Crew Program contract with NASA — signed in 2014, alongside a smaller $2.6 billion contract awarded to SpaceX — has now produced exactly one crewed flight that failed to return its crew aboard its own vehicle, after more than a decade of development delays, two uncrewed test flights (one of which also failed to reach the ISS), and multiple billion-dollar cost overruns absorbed by Boeing itself. SpaceX’s competing Crew Dragon, by contrast, has completed eleven operational crewed missions to the ISS since its first crewed flight in May 2020, has carried more than fifty astronauts safely to and from the station, and has now also rescued the two astronauts that Boeing’s vehicle was unable to return.
Whether Starliner ever flies humans again remains, as of mid-2026, an open question. As documented in NASA’s official return-announcement statement, the agency has not committed to a specific date for the next Starliner mission, crewed or uncrewed. The engineering questions about the service-module thrusters remain partially unresolved because the affected hardware no longer exists. Boeing has indicated that it intends to address the propulsion issues in subsequent vehicles and that it remains committed to the Commercial Crew Program. NASA, for its part, has indicated that it still wants a second commercial crew provider as a backup to SpaceX. Whether the second provider continues to be Boeing, and whether the next Starliner flight occurs in 2026, 2027, or later, will depend on technical, financial, and political decisions that the agency has not yet made publicly. The 286 days that Williams and Wilmore spent in orbit after their eight-day mission ended are, in this respect, a piece of operational evidence whose institutional consequences are still in the process of being worked out.
