The Boeing CST-100 Starliner team has received encouraging news regarding the spacecraft’s return to Earth. The completion of ground tests for the spacecraft’s thrusters, which have been immobilized in space since early June, marks a significant step forward. Boeing and NASA had been awaiting these tests before initiating plans for the Starliner’s journey back home.
A recent update confirmed, “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 shifting their focus to data analysis.” The testing aimed to investigate thruster performance issues, particularly understanding why some thrusters were rendered inoperative during the flight and assessing the implications of possibly reintroducing them for the crewed flight test.
The term “de-selected” refers to the thrusters that unexpectedly ceased functioning. Helium tanks, which regulate the thruster operations, experienced leaks before and during the Starliner’s launch, causing several delays. Although officials previously noted that the spacecraft is carrying 70 hours’ worth of helium—far more than the required seven hours—they mentioned that, although the Starliner could return now if necessary, they are not yet fully prepared for that scenario.
In the latest communications, NASA and Boeing indicated that a potential return flight could occur by the end of this month. However, the timeline has since become less precise. “Boeing and NASA engineers will undertake thruster disassembly and inspections, moving forward to finalize flight rationale in support of readiness reviews for Starliner’s return to Earth with commander Butch Wilmore and pilot Suni Williams in the upcoming weeks.”