The Boeing CST-100 Starliner crew received promising news about its return to Earth. The recent completion of ground testing on the spacecraft’s thrusters, which have been inactive since early June, paves the way for planning its homeward journey. Boeing and NASA had been awaiting the results of these tests to strategize the return.
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 goal of these tests was to understand the degradation of some thrusters that were deactivated during flight and to assess the implications of potentially reactivating them for the forthcoming Crew Flight Test.
The term “de-selected” refers to thrusters that ceased functioning. Prior to and during the launch, the helium tanks controlling these thrusters experienced leaks, causing multiple postponements. Officials noted in a press conference last month that the Starliner has 70 hours of helium onboard, despite only needing seven for its flight. Although they indicated the spacecraft could return immediately if necessary, they expressed that it is not yet ready for the journey home.
The latest communication from NASA and Boeing suggested a possible return flight by 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.”