The Boeing CST-100 Starliner may soon be heading back to Earth following the completion of ground testing on its thrusters, which have kept it in orbit since early June. Both Boeing and NASA were waiting for these tests to wrap up before planning the spacecraft’s return journey.
An update indicated that testing of the Starliner’s Reaction Control System (RCS) thrusters at the White Sands Test Facility in New Mexico has concluded, allowing teams to focus on reviewing the gathered data. The purpose of this testing was to evaluate thruster performance issues, particularly why some thrusters were unable to function properly during flight and to assess the implications of bringing those thrusters back into operation for the Crew Flight Test.
Some thrusters were “de-selected” during the mission due to operational failures. It was reported that helium tanks, which are crucial for controlling the thrusters, experienced leaks before and during the launch, causing significant delays. Last month, officials noted that while the spacecraft has 70 hours of helium aboard, it only requires seven for its operations. While they mentioned the Starliner could return to Earth if necessary, they clarified they are not fully prepared for that to happen quite yet.
In a more recent update, NASA and Boeing indicated that a return flight might occur at the end of this month. However, the timeline is now 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.”