The Boeing CST-100 Starliner crew received encouraging news regarding their return to Earth. Recent ground tests of the spacecraft’s thrusters, which have kept it in orbit since early June, have been completed. Boeing and NASA were awaiting the results of these tests to start planning the vessel’s homeward journey.
An update disclosed 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 turning their attention to data reviews.” The objective of the tests was to examine thruster degradation to gain insight into why some thrusters were deactivated during flight and to assess the implications of potentially returning them to service for the remaining Crew Flight Test.
When officials refer to “de-selected” thrusters, they mean that some ceased functioning. Prior to and during the Starliner launch, there were leaks in the helium tanks that control the thrusters, resulting in several delays. During a press conference last month, officials noted that the ship has 70 hours’ worth of helium, despite only needing seven, indicating the vessel is technically ready for a return if necessary. However, they mentioned that preparations for this return are not yet fully complete.
The latest update from NASA and Boeing suggested that a return flight could be possible by the end of this month. The timeline has since become less defined: “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.”