The Boeing CST-100 Starliner team has received positive news regarding the spacecraft’s return to Earth. Recent ground testing of the spacecraft’s thrusters, which have left it in space since early June, has been completed. Boeing and NASA were awaiting these test results to begin planning for the vehicle’s return journey.
According to a statement released last week, “Ground testing of a Starliner Reaction Control System (RCS) thruster at the White Sands Test Facility in New Mexico is complete, and teams are now focusing on reviewing the data.” The objective of the tests was to assess thruster performance, focusing on the degradation of certain thrusters that had to be de-selected during flight. This is crucial for understanding how to potentially reintegrate them into the system for future missions.
The term “de-selected” refers to thrusters that failed to operate properly. Issues arose with tanks that hold helium for thruster control, resulting in leaks both prior to and during the Starliner’s launch, which has caused various delays. Despite having 70 hours’ worth of helium available—far more than the seven hours required—officials indicated that while the spacecraft could return if necessary, they are not fully prepared for that yet.
The latest communication from NASA and Boeing suggested that a return flight could happen at the end of this month; however, the timeframe has now shifted to a more flexible schedule. “Boeing and NASA engineers will proceed with thruster disassembly and inspections, and continue finalizing flight rationale to support readiness reviews for Starliner’s upcoming return to Earth with commander Butch Wilmore and pilot Suni Williams in the coming weeks.”