The crew of the Boeing CST-100 Starliner is receiving positive news regarding its return to Earth. Recently, ground testing of the spacecraft’s thrusters, which have kept it in space since early June, has been completed. Boeing and NASA had been awaiting these tests to initiate planning for the spacecraft’s homeward journey.
An update from last week indicated, “Ground testing of a Starliner Reaction Control System (RCS) thruster at White Sands Test Facility in New Mexico is complete, and teams are now focusing on data reviews.” The objective of these tests was to investigate thruster degradation to understand why some thrusters were not operational during flight and to evaluate the potential impacts of returning these thrusters to service for the upcoming Crew Flight Test.
The term “de-selected” refers to thrusters that failed to function. Issues with helium tanks that control the thrusters resulted in leaks before and during the Starliner launch, causing multiple delays. During a press conference last month, officials stated that the spacecraft is equipped with 70 hours’ worth of helium, though it requires only seven hours for its operations. While they mentioned earlier this month that the vessel could return immediately if necessary, it appears they are not fully prepared for that eventuality.
In their latest update, NASA and Boeing suggested that a return flight could occur at the end of this month. However, the schedule is now less specific: “Boeing and NASA engineers will proceed with thruster disassembly and inspections, and advance towards finalizing flight rationale in support of readiness reviews for Starliner’s planned return to Earth with commander Butch Wilmore and pilot Suni Williams in the coming weeks.”