The crew of the Boeing CST-100 Starliner has received positive news regarding their return to Earth. Recent ground tests of the spacecraft’s thrusters, which have left it in orbit since early June, have been successfully completed. Boeing and NASA had been awaiting the conclusion of these tests to begin planning for the Starliner’s return.
According to an update released last week, “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 tests focused on identifying thruster degradation to understand why certain thrusters were de-selected during flight and to assess any potential impacts of reactivating those thrusters for the remaining Crew Flight Test.
The term “de-selected” refers to thrusters that malfunctioned. Prior to and during the launch, leaks were detected in the helium tanks that control the thrusters, causing several delays. Officials stated last month that the Starliner has 70 hours’ worth of helium available, though it only requires seven hours. While they indicated earlier this month that the spacecraft could return immediately if necessary, they also emphasized that they are not fully prepared for its return just yet.
In the latest updates, NASA and Boeing mentioned that a return flight could occur at the end of this month. However, the timeline has become less precise: “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.”