The Boeing CST-100 Starliner team has received encouraging news regarding its return to Earth. Testing of the spacecraft’s thrusters, which have left it in orbit since early June, has now been successfully completed. Boeing and NASA were awaiting the completion of these tests before starting to plan the Starliner’s homeward journey.
“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,” an update stated last week. The purpose of the testing was to evaluate thruster performance and understand why some thrusters were not usable during flight, as well as the potential effects of reactivating them on the overall mission.
Officials indicated that some thrusters were “de-selected,” meaning they became inoperative. This issue arose due to leaking helium tanks, which affected the thrusters both before and during the Starliner launch, resulting in several delays. Despite having 70 hours’ worth of helium onboard—far more than the seven hours needed—officials mentioned last month that while the spacecraft could return to Earth at any time, they are not yet fully prepared for the landing.
The latest update from NASA and Boeing mentioned that a return could be possible by the end of this month. However, the timeline has now become more flexible: “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.”