The Boeing CST-100 Starliner crew has received encouraging news regarding their return to Earth. Recently completed ground tests on the spacecraft’s thrusters, which have kept it in space since early June, were a necessary step before NASA and Boeing could begin planning the vessel’s homeward journey.
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 objective of these tests was to assess the degradation of thrusters to understand why some were rendered inoperative during flight and to determine the potential impact of reactivating those thrusters on the overall crew flight test.
The term “de-selected” refers to some thrusters that stopped functioning. Issues with helium tanks that control the thrusters caused leaks both before and during the launch, resulting in multiple delays. Officials stated last month that the spacecraft is equipped with 70 hours’ worth of helium, significantly more than the seven hours it actually requires. While it was mentioned that the Starliner could return to Earth if necessary, teams confirmed they are not yet fully prepared for that eventuality.
NASA and Boeing previously indicated that a return flight could occur 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.”