The crew of the Boeing CST-100 Starliner received promising news regarding their return to Earth. The recent completion of ground tests on the spacecraft’s thrusters, which had been stranded in space since early June, marks a significant step forward. Boeing and NASA were awaiting these tests to begin planning for the spacecraft’s return.
An update released last week noted, “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 the tests was to assess thruster performance and understand why some thrusters were inoperative during flight, as well as to evaluate the potential implications of reactivating those thrusters for the upcoming Crew Flight Test.
The term “de-selected” refers to the thrusters that ceased functioning. Issues arose with helium tanks that control the thrusters, which were found to be leaking prior to and during the Starliner launch, resulting in multiple delays. Officials stated in a press conference last month that the spacecraft holds 70 hours’ worth of helium, while only seven hours are required for the mission. They indicated that while the spacecraft could technically return home immediately if necessary, preparations for that return are not yet fully in place.
Previously, NASA and Boeing mentioned a potential return flight at the end of this month. However, the timeline is now less defined: “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.”