The crew of the Boeing CST-100 Starliner received positive news regarding their impending 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 before planning for the spacecraft’s homecoming.
A recent update noted, “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 tests aimed to assess thruster performance issues that led to several thrusters being “de-selected” during flight, allowing teams to better understand the causes and implications of returning these thrusters to operational status.
The term “de-selected” refers to certain thrusters that ceased functioning. Prior to and during the Starliner launch, the helium tanks controlling the thrusters experienced leaks, resulting in multiple delays. Officials mentioned in a press conference last month that the spacecraft has 70 hours of helium on board, despite only needing seven hours for its operations. While they indicated that the ship could theoretically return immediately, they are not yet prepared for that scenario.
As of the latest communication, NASA and Boeing suggested that a return flight might occur at the end of this month, but the timeline has since become less specific. “Boeing and NASA engineers will proceed with thruster disassembly and inspections, and move forward in 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,” the update stated.