The crew of the Boeing CST-100 Starliner has received promising news regarding their return to Earth. Recent ground tests of the spacecraft’s thrusters, which have left it stranded in space since early June, have been successfully completed. Boeing and NASA were awaiting the results of these tests before making plans for the spacecraft’s homecoming.
An update shared late last week indicated, “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 primary goal of the tests was to assess thruster performance degradation in order to understand why some thrusters were deactivated during the flight and the potential impacts of reactivating them.
The term “de-selected” refers to thrusters that ceased functioning. Prior to and during the Starliner’s launch, the helium tanks that control the thrusters experienced leaks, leading to multiple delays. Officials stated last month that the spacecraft contains 70 hours of helium, despite only requiring seven. Although they mentioned earlier this month that the spacecraft could return to Earth if necessary, they also noted that preparations for the return were not yet complete.
In their latest update, NASA and Boeing hinted that a return flight could occur at the end of this month. However, that timeline is now less certain: “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.”