The Boeing CST-100 Starliner crew has received positive updates regarding their anticipated return home. Recently, ground testing of the spacecraft’s thrusters, which have been dormant since early June, was successfully completed. Boeing and NASA were waiting for these tests to finish before planning the spacecraft’s return trip.
An update from last week stated, “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.” The purpose of the testing was to assess thruster degradation and understand why some thrusters were not used during the flight, as well as the potential effects of returning them to operation for the Crew Flight Test.
Some thrusters were categorized as “de-selected” because they ceased functioning. This issue stemmed from leaks in the helium tanks that manage the thrusters, which caused several delays both before and during the Starliner’s launch. A press conference held last month revealed that the spacecraft has 70 hours’ worth of helium onboard, despite only requiring seven for its operations. While officials mentioned earlier in the month that the Starliner could return to Earth immediately if necessary, they indicated that they are not yet fully prepared for that scenario.
In their most recent update, NASA and Boeing noted that a return flight might be possible by the end of this month. However, the timeline has since 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.”