The Boeing CST-100 Starliner crew has received encouraging news regarding their return to Earth. Recent ground tests on the spacecraft’s thrusters, which have kept it in orbit since early June, have been completed. Boeing and NASA had been awaiting the results of these tests to begin planning for the spacecraft’s homecoming.
An update released recently stated, “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 turning their attention to data reviews.” The purpose of the testing was to investigate thruster performance issues that led to some thrusters being inactive during flight, as well as assessing any effects of reactivating them on the mission.
The term “de-selected” refers to those thrusters that became non-functional. Leaks were identified in the helium tanks that control the thrusters before and during the Starliner launch, which contributed to multiple delays. Officials indicated that while the Starliner currently possesses 70 hours’ worth of helium—far exceeding the seven hours required for its journey—there is still reluctance to initiate a return at this moment.
Previously, NASA and Boeing suggested that a return flight could occur by the end of this month. However, the timeline has since become less definite: “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.”