The Boeing CST-100 Starliner crew received encouraging news regarding their return to Earth. Recent ground testing of the spacecraft’s thrusters, which had left it stranded in space since early June, has been successfully completed. Boeing and NASA were waiting for these tests to finalize plans for the vessel’s homecoming.
An update from last week confirmed, “Ground testing of a Starliner Reaction Control System (RCS) thruster at the White Sands Test Facility in New Mexico is complete, and teams are now focusing on data reviews.” The purpose of the tests was to examine thruster degradation and understand why some thrusters were disabled during flight, as well as to evaluate the implications of potentially reactivating those thrusters for the Crew Flight Test.
The term “de-selected” refers to thrusters that ceased functioning. Prior to and during the Starliner launch, the helium tanks that control the thrusters experienced leaks, resulting in several delays. Officials noted that the spacecraft currently has 70 hours of helium on board, significantly more than the seven hours required for operations. Although they stated earlier this month that the Starliner could come back to Earth if necessary, they expressed that they are not entirely prepared for that scenario.
In the latest update, NASA and Boeing mentioned that a return flight could happen at the end of this month. However, the timeline is now less certain: “Boeing and NASA engineers will proceed with thruster disassembly and inspections, and continue to finalize flight rationale to support readiness reviews for Starliner’s fundamental return to Earth with commander Butch Wilmore and pilot Suni Williams in the coming weeks.”