The crew of the Boeing CST-100 Starliner has received encouraging news regarding its return to Earth. Recent ground tests of the spacecraft’s thrusters, which have kept it in orbit since early June, have been successfully completed. Boeing and NASA were awaiting the results of these tests before finalizing plans for the Starliner’s homecoming.
An update last week confirmed, “Ground testing of a Starliner Reaction Control System (RCS) thruster at White Sands Test Facility in New Mexico is complete, and teams are now turning their attention to data reviews.” The testing aimed to assess thruster degradation and understand why some thrusters were inoperable during the flight, as well as the potential impacts of reinstating those thrusters for the upcoming Crew Flight Test.
The term “de-selected” refers to thrusters that became non-functional. Issues with helium tanks controlling the thrusters led to leaks both before and during the launch, causing several delays. Despite having 70 hours of helium onboard—far exceeding the seven hours required—officials indicated last month that the spacecraft is not yet ready for immediate return.
In their latest update, NASA and Boeing mentioned that a return flight could occur by the end of this month, though the timeline has since become less specific. “Boeing and NASA engineers will proceed with thruster disassembly and inspections, and advance preparations for readiness reviews, supporting Starliner’s scheduled return to Earth with commander Butch Wilmore and pilot Suni Williams in the following weeks.”