The Boeing CST-100 Starliner crew has received encouraging news regarding their spacecraft’s return to Earth. Recent ground tests of the spacecraft’s thrusters, which have left it stranded in space since early June, have now concluded. Boeing and NASA have been awaiting the completion of these tests to initiate planning for the Starliner’s homecoming.
An update released 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 primary goal of these tests was to understand thruster degradation to determine why some thrusters were non-functional during the flight and assess the impact of potentially reactivating them on the upcoming Crew Flight Test.
The term “de-selected” refers to thrusters that ceased to operate. Issues with helium tanks, which control the thrusters, were identified both prior to and during the launch, resulting in several delays. Officials noted last month that the spacecraft is equipped with 70 hours of helium, despite only needing seven for its operations. They mentioned earlier this month that the Starliner could return at any time if necessary, but they also indicated that they are not fully prepared for that eventuality.
At the last briefing, NASA and Boeing suggested that a return flight could occur at the end of this month. However, the timeline has since become less defined: “Boeing and NASA engineers will proceed with thruster disassembly and inspections and will continue to finalize 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.”