The Boeing CST-100 Starliner crew has received positive news regarding their return to Earth. Recently completed ground tests of the spacecraft’s thrusters, which have left it orbiting since early June, signal progress. Boeing and NASA awaited these tests to start planning the vehicle’s homeward journey.
An update from last week reported, “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 primary goal of these tests was to analyze thruster performance degradation to better understand the reasons some thrusters were deactivated during flight and assess the implications of reactivating them on the entire Crew Flight Test.
The term “de-selected” refers to thrusters that had ceased operation. Prior to and during the Starliner’s launch, helium tanks, which manage the thrusters, were found to be leaking, resulting in several delays. A press conference the previous month noted that while the ship contains 70 hours’ worth of helium, only seven hours are needed. Officials indicated the spacecraft could return immediately if necessary, although they expressed that they were not fully prepared for that scenario.
The last update from NASA and Boeing suggested a potential return flight at the month’s end, but the timeline has since become less specific. They stated, “Boeing and NASA engineers will proceed with thruster disassembly and inspections, and work on finalizing flight rationale in support of readiness reviews for Starliner’s planned return to Earth with commander Butch Wilmore and pilot Suni Williams in the coming weeks.”