The Boeing CST-100 Starliner crew has received encouraging news regarding the spacecraft’s return to Earth. Ground testing of its thrusters, which have left the spacecraft in orbit since early June, has been completed. Boeing and NASA were awaiting these tests to begin planning for the spacecraft’s homecoming.
An update released last week stated, “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 focused on data reviews.” The objective of the tests was to evaluate the degradation of the thrusters and to understand why some were not functional during the mission.
“De-selected” refers to those thrusters that failed to operate. Prior to and during the Starliner launch, there were issues with helium tanks controlling the thrusters, resulting in several delays. Officials noted that the spacecraft contains enough helium for 70 hours of operation, despite only needing seven. Earlier this month, they indicated that the Starliner could return immediately if necessary, though it is not yet fully prepared for the journey home.
The latest update from NASA and Boeing suggests that a return flight could be possible 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.”