The Boeing CST-100 Starliner crew is poised to receive promising news regarding their return to Earth. The recent completion of ground testing for the spacecraft’s thrusters, which have left it in orbit since early June, paves the way for planning its homeward journey.
An update released late 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 focusing on data reviews.” The objective of the testing was to assess thruster degradation, helping engineers determine why some thrusters were rendered inactive during flight and what implications restoring them to service might have for the upcoming Crew Flight Test.
The term “de-selected” is used to indicate that some thrusters ceased to function. Issues with helium tanks that control the thrusters arose both prior to and during the Starliner launch, leading to several delays. At a press conference last month, officials indicated that the spacecraft is equipped with 70 hours’ worth of helium, far exceeding the seven hours it actually requires. Although they stated earlier this month that the ship could return immediately if necessary, they noted that they are not yet fully prepared for the operation.
In the latest update, NASA and Boeing mentioned that a return flight might occur at the end of this month, but the timeline has since become less defined. “Boeing and NASA engineers will proceed with thruster disassembly and inspections, moving 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.”