The crew of the Boeing CST-100 Starliner has received positive news regarding their imminent return to Earth. Recent ground testing of the spacecraft’s thrusters, which have kept it in orbit since early June, has been completed. Boeing and NASA were awaiting these results to start planning the spacecraft’s return trip.
“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 from late last week stated. The purpose of the test was to examine thruster degradation, which would help the teams understand why some thrusters were unable to function during the flight and to assess any potential effects of bringing those thrusters back into operation for the Crew Flight Test.
Some thrusters were described as “de-selected,” meaning they stopped working during the mission. Helium tanks, which control the thrusters, experienced leaks before and during the launch, causing multiple delays. Officials indicated last month that the spacecraft is equipped with 70 hours of helium, even though only seven hours are necessary. While they mentioned earlier this month that the Starliner could return to Earth immediately if required, they clarified that they are not yet fully prepared for its homecoming.
In their last update, NASA and Boeing suggested that a return flight might occur at the end of the month. However, the timeline is now less specific: “Boeing and NASA engineers will proceed with thruster disassembly and inspections and will continue finalizing flight rationale in support of readiness reviews for Starliner’s planned return to Earth with commander Butch Wilmore and pilot Suni Williams in the coming weeks.”