The crew of the Boeing CST-100 Starliner has received positive news regarding their eventual return to Earth. Recent ground testing of the spacecraft’s thrusters, which have left it in orbit since early June, has been completed. Boeing and NASA were awaiting the results of these tests before finalizing plans for the vessel’s homebound journey.
An update released last week confirmed, “Ground testing of a Starliner Reaction Control System (RCS) thruster at White Sands Test Facility in New Mexico is complete, and teams are now focusing on data reviews.” The goal of the testing was to observe the degradation of the thrusters, helping the team understand why some of them were inoperable during the flight and the potential effects of reactivating those thrusters on the Crew Flight Test.
The term “de-selected” refers to the thrusters that ceased functioning. The tanks containing the helium needed to control the thrusters were found to be leaking before and during the Starliner’s launch, which caused several delays. Officials indicated last month that the spacecraft has 70 hours’ worth of helium, despite only needing seven. While they mentioned earlier this month that the Starliner could return immediately if necessary, they noted they aren’t fully prepared for that at this stage.
According to the latest update from NASA and Boeing, a return flight was tentatively scheduled for the end of this month. The timeline, however, 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.”