NASA and Boeing have announced a delay in the return of the Starliner capsule, initially scheduled after a week-long stay at the International Space Station (ISS). The delay, which now extends the mission to nearly three weeks, is mainly due to thruster problems and a rescheduled spacewalk. The new landing date is set for June 26, at White Sands Space Harbor in New Mexico. The event will be broadcast live on NASA Television.
The Starliner’s engine anomalies and what they entailed
During the first docking attempt on the ISS on June 6, Starliner experienced failures in five of its 28 reaction control thrusters, although four of them were later restored. The malfunction required extensive data analysis and a subsequent firing test, which increased confidence in the reliability of the thrusters for the remainder of the mission. It is important to note that a thruster remains idle due to persistent low pressure. Furthermore, a robotic camera inspection carried out by Canadarm2 provided valuable information on the condition of the thrusters.
Alongside the thruster problems, Starliner faced several helium leaks in its reaction control system (RCS). These leaks were initially detected on the launch pad in early May and continued throughout the mission. NASA and Boeing are conducting a detailed analysis to determine the root cause, as the helium leaks and RCS thruster problems appear to have different origins. Despite these issues, losses have stabilized and a new way of return has been certified to mitigate potential risks.
Mission adaptations
The mission’s extended duration allowed NASA and Boeing to conduct comprehensive systems evaluations and consequently improve understanding of Starliner’s performance. This mission, called Crew Flight Test (CFT), involves astronauts Barry Wilmore and Suni Williams, who played a crucial role in testing the capsule’s systems in orbit. As part of the updated schedule, a maintenance spacewalk to the ISS, originally scheduled for June 13, is now planned for June 24. In case of further delays, the Starliner exit will take priority.
The CFT mission has as its fundamental objective the certification of Starliner for regular operational missions to the ISS, a role it will share with SpaceX’s Dragon capsule. Despite the technical difficulties, the mission met 77 of its 87 objectives, with the remainder to be addressed during the release and landing phases.
