The crew of the Boeing CST-100 Starliner received encouraging news regarding their return to Earth. Recent ground testing of the spacecraft’s thrusters, which have left it stranded in space since early June, has been completed. Boeing and NASA were awaiting the results of these tests to start planning for the spacecraft’s homecoming.
An update released late 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 focusing on data reviews.” The objective of the test was to investigate thruster degradation, helping teams understand why some thrusters were not operational during flight and the potential effects of reactivating them on the Crew Flight Test.
The term “de-selected” refers to the failure of certain thrusters to function. Prior to and during the Starliner launch, the helium tanks that control the thrusters were found to be leaking, causing several delays. Officials mentioned at a press conference last month that the spacecraft contains 70 hours’ worth of helium, though it only requires seven hours. While they indicated that the craft could return to Earth immediately if necessary, they also noted that they are not yet fully prepared for that scenario.
In the most recent update, NASA and Boeing indicated that a return flight could potentially happen at 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 planned return to Earth with commander Butch Wilmore and pilot Suni Williams in the coming weeks.”