The Boeing CST-100 Starliner crew received encouraging news regarding their return to Earth. Recently, ground tests of the spacecraft’s thrusters, which have kept it in space since early June, were completed. Boeing and NASA had been awaiting these tests to start planning the spacecraft’s homeward journey.
A recent update 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 primary goal of the test was to analyze thruster degradation to understand why some thrusters were not operational during flight, and to evaluate the implications of potentially reactivating them for the Crew Flight Test.
Officials noted that “de-selected” refers to the thrusters that ceased functioning. Prior to and during the Starliner launch, there were leaks in the helium tanks that control the thrusters, resulting in several delays. Although there is sufficient helium onboard for 70 hours of operation, the spacecraft only requires seven. Officials indicated last month that the spacecraft could return immediately if necessary, but emphasized that they are not fully prepared for the return.
At the latest briefing, NASA and Boeing hinted that a return flight could occur by the end of the month. However, the timeline has since become more uncertain: “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.”