The crew of the Boeing CST-100 Starliner has received promising news regarding their return to Earth. Ground testing of the spacecraft’s thrusters, which have kept it in space since early June, has recently been completed. Both Boeing and NASA had been awaiting these test results before planning the Starliner’s return trip.
A recent update stated that ground testing of a Starliner Reaction Control System (RCS) thruster at White Sands Test Facility in New Mexico is now finished, and the teams are focusing on data reviews. The objective of the tests was to observe thruster degradation to better understand why some thrusters stopped working in flight and what impacts returning those thrusters to service might have on the Crew Flight Test.
By “de-selected,” officials mean that some of the thrusters ceased functioning. Tanks containing helium, which controls the thrusters, were leaking before and during the Starliner launch, causing multiple delays. At a press conference last month, officials mentioned that the spacecraft has 70 hours’ worth of helium onboard, although it only needs seven. While earlier this month, they said the craft could return to Earth if necessary, they also emphasized they are not ready for it to do so just yet.
In the most recent update, NASA and Boeing indicated that a return flight could happen at the end of this month. However, the timeline is now a bit less clear: “Boeing and NASA engineers will proceed with thruster disassembly and inspections and will move forward with finalizing flight rationale to support readiness reviews for Starliner’s return to Earth with commander Butch Wilmore and pilot Suni Williams in the coming weeks.”