The Boeing CST-100 Starliner crew has received positive news regarding their return to Earth. Testing of the spacecraft’s thrusters, which have kept it in space since early June, has recently concluded. Boeing and NASA had deferred planning the vessel’s return trip until these tests were completed.
An update released 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 turning their attention to data reviews.” The primary goal of the tests was to evaluate thruster degradation to understand why some thrusters were de-selected during flight and assess the potential impacts of bringing them back into service.
The term “de-selected” refers to those thrusters that ceased functioning. Prior to and during the Starliner’s launch, helium tanks that control these thrusters experienced leaks, resulting in multiple delays. Officials mentioned that while the spacecraft has 70 hours’ worth of helium onboard, it only requires seven. They indicated earlier this month that the craft could theoretically return now but emphasized that preparations are not fully complete.
In the most recent report, NASA and Boeing mentioned that a return flight could be possible by the end of this month, although the timeline has become less specific. “Boeing and NASA engineers will proceed with thruster disassembly and inspections, and move forward with 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 coming weeks.”