The crew of the Boeing CST-100 Starliner has received some encouraging news regarding its anticipated return journey. Earth-based testing of the spacecraft’s thrusters, which have kept it in space since early June, has recently been completed. Boeing and NASA had been awaiting these test results to initiate planning for the spacecraft’s return.
An update provided late 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 focusing on data reviews.” The purpose of the testing was to analyze thruster degradation to understand why certain thrusters were rendered inoperable during the flight and to evaluate any potential impacts of reactivating these thrusters on the Crew Flight Test.
The term “de-selected” indicates that some thrusters failed to operate. Prior to and during the launch of Starliner, leaks were detected in the helium tanks that control the thrusters, causing several delays. During a press conference last month, officials noted that the spacecraft has 70 hours of helium onboard, even though it only requires seven. They mentioned earlier this month that the spacecraft could return at any moment if necessary, but they indicated that it is not fully prepared for the journey back just yet.
In the most recent update, NASA and Boeing stated that a return flight could occur by the end of this month; however, the timeline has become less specific. “Boeing and NASA engineers will proceed with thruster disassembly and inspections, and advance toward 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 upcoming weeks.”