The crew of the Boeing CST-100 Starliner received encouraging news regarding their return to Earth. Ground testing of the spacecraft’s thrusters, which have left it stranded in space since early June, has been successfully concluded. Boeing and NASA were awaiting the completion of these tests before initiating plans for the spacecraft’s homecoming.
An update from 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 assess thruster degradation, allowing teams to understand why certain thrusters failed during flight and the potential effects of reactivating those thrusters for the upcoming Crew Flight Test.
“De-selected” refers to the thrusters that ceased operation during the mission. Prior to and during the Starliner launch, leaks were discovered in the helium tanks that control the thrusters, causing several delays. Officials mentioned that the Starliner has 70 hours of helium on board, despite only needing seven hours. While they indicated earlier this month that the spacecraft could return immediately if necessary, they also stated they were not yet ready for that eventuality.
In a recent update, NASA and Boeing suggested that a return flight could occur at the end of this month. However, the timeline has 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.”