The Boeing CST-100 Starliner crew has received optimistic news regarding their return journey. Recent ground testing of the spacecraft’s thrusters, which has kept it in orbit since early June, has been completed. Boeing and NASA had been awaiting the outcome of these tests to initiate plans for the spacecraft’s return.
An update released last week stated, “Ground testing of a Starliner Reaction Control System (RCS) thruster at White Sands Test Facility in New Mexico is complete, and teams are now turning their attention to data reviews.” The purpose of the tests was to evaluate thruster degradation to better understand the reasons behind the failure of certain thrusters during flight and the potential impact of reactivating them on the overall Crew Flight Test.
Some thrusters were referred to as “de-selected,” indicating that they had ceased to function. Issues with helium tanks, which control the thrusters, had led to leaks prior to and during the Starliner’s launch, resulting in several delays. Officials noted last month that the spacecraft carries 70 hours’ worth of helium, despite only needing seven. Although they mentioned earlier this month that the Starliner could return if necessary, they indicated that more preparations are needed before it can safely return.
NASA and Boeing earlier provided an update suggesting that a return flight could be possible at the end of this month. However, the timeline has since become less specific: “Boeing and NASA engineers will proceed with thruster disassembly and inspections and move forward with finalizing flight rationale in support of readiness reviews for Starliner’s nominal return to Earth with commander Butch Wilmore and pilot Suni Williams in the coming weeks.”