The crew of the Boeing CST-100 Starliner recently received encouraging news regarding their return to Earth. The successful testing of the spacecraft’s thrusters, which had left it stranded in space since early June, has been completed. Both Boeing and NASA were awaiting the results from these tests before making arrangements for the craft’s journey back home.
An update released last week confirmed, “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 aim of the tests was to assess thruster degradation to understand why some thrusters malfunctioned during flight and the potential effects of reactivating those thrusters on the upcoming Crew Flight Test.
The term “de-selected” refers to those thrusters that ceased functioning. Prior to and during the Starliner’s launch, leaks were detected in the helium tanks responsible for regulating the thrusters, which contributed to several delays. Officials indicated in a recent press conference that the spacecraft has 70 hours of helium available, significantly more than the seven hours it requires. While NASA and Boeing asserted earlier this month that the spacecraft could return immediately if necessary, they are not yet fully prepared for that eventuality.
In their latest update, NASA and Boeing indicated that a possible return flight could occur at the end of this month. However, the timeline is now 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.”