The Boeing CST-100 Starliner crew received encouraging news regarding their upcoming return to Earth. Testing of the spacecraft’s thrusters, which have kept it in space since early June, has now been completed on the ground. Boeing and NASA had been awaiting the results of these tests to begin planning for the spacecraft’s return journey.
An announcement last week confirmed the successful testing of a Starliner Reaction Control System (RCS) thruster at the White Sands Test Facility in New Mexico. The primary goal of the tests was to observe thruster degradation to understand why some thrusters were disabled during the mission and to evaluate the potential impact of reactivating those thrusters on the Crew Flight Test.
The term “de-selected” refers to those thrusters that ceased functioning. Prior to and during the Starliner’s launch, the helium tanks that regulate the thrusters were leaking, causing several delays. During a press conference last month, officials noted that the spacecraft still has 70 hours of helium available, despite only requiring seven for its operations. They indicated earlier this month that the Starliner could return immediately if necessary, but stated they were not fully prepared for that scenario just yet.
In the latest update, NASA and Boeing mentioned that a return flight could be scheduled for the end of this month. However, the timeline has since become less specific. The announcement stated, “Boeing and NASA engineers will proceed with thruster disassembly and inspections, and continue finalizing flight rationale to support readiness reviews for Starliner’s nominal return to Earth with commander Butch Wilmore and pilot Suni Williams in the coming weeks.”