The crew of the Boeing CST-100 Starliner has received positive news regarding their return to Earth. Recent ground tests of the spacecraft’s thrusters, which have kept it in orbit since early June, have been completed. Boeing and NASA awaited these tests before beginning preparations for the vehicle’s journey home.
An update from 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 focusing on data reviews.” The goal of the tests was to assess thruster degradation, allowing engineers to understand why some thrusters were not operational during the flight and the potential effects of reinstating those thrusters on the Crew Flight Test.
The term “de-selected” refers to certain thrusters that became nonfunctional. Issues with helium tanks that control the thrusters led to leaks both before and during the Starliner’s launch, resulting in multiple delays. Despite having 70 hours of helium available—far more than the seven hours required—the spacecraft is not yet ready for an immediate return, according to officials who spoke at a press conference last month.
Earlier, NASA and Boeing indicated that a return flight might happen at the end of this month. However, the timeline has since become less defined: “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.”