The crew of the Boeing CST-100 Starliner has received positive news regarding their return to Earth. Tests of the spacecraft’s thrusters, which have kept it in orbit since early June, have been successfully completed. Boeing and NASA were awaiting the results of these tests to begin planning the spacecraft’s journey home.
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 turning their attention to data reviews.” The aim of the test was to assess thruster degradation to understand the reasons behind the in-flight failure of some thrusters and to evaluate the potential impact of reactivating those thrusters on the overall Crew Flight Test.
Some thrusters were “de-selected,” indicating that they had malfunctioned. Issues included helium leaks in the tanks controlling the thrusters, which caused several delays prior to the Starliner launch. Although the spacecraft has 70 hours of helium on board, it only requires seven. Earlier this month, officials indicated that the Starliner could return to Earth immediately if needed, but they stated they are not yet fully prepared for that event.
In the most recent update, both NASA and Boeing mentioned that a return flight could occur by the end of this month. However, the timeline has become less specific: “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.”