The crew of the Boeing CST-100 Starliner has received encouraging news regarding its return to Earth. The recent completion of ground tests for the spacecraft’s thrusters, which have left it orbiting since early June, marks a significant step forward. Boeing and NASA had been awaiting these test results before initiating plans for the spacecraft’s homeward journey.
An update released 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 purpose of the tests was to assess thruster performance degradation, helping teams understand why some thrusters were deactivated during the flight and the potential effects of reactivating them on the upcoming Crew Flight Test.
The term “de-selected” refers to some thrusters that became inoperative. There were issues with helium tanks, which control the thrusters, as they experienced leaks before and during the Starliner launch, causing several delays. Despite having 70 hours’ worth of helium onboard—far more than the required seven hours—officials stated last month that while the spacecraft could return immediately if necessary, they preferred to wait.
In the latest communication, NASA and Boeing mentioned that a return flight could potentially occur by the end of this month. However, the timeframe has since become less defined: “Boeing and NASA engineers will proceed with thruster disassembly and inspections and continue finalizing the flight rationale to support readiness reviews for Starliner’s planned return to Earth, with commander Butch Wilmore and pilot Suni Williams, in the coming weeks.”