The crew of the Boeing CST-100 Starliner has received encouraging news regarding its return to Earth. Recent ground testing of the spacecraft’s thrusters, which have kept it in orbit since early June, has been completed. This milestone allows Boeing and NASA to begin planning for the Starliner’s journey back home.
An announcement shared 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 purpose of the tests was to assess thruster performance issues, particularly understanding why some thrusters were not operational during the flight and determining any effects that could result from reinstating those thrusters for the remainder of the Crew Flight Test.
Some thrusters were deemed “de-selected,” meaning they ceased functioning. Prior to and during the Starliner launch, tanks containing the helium for controlling the thrusters experienced leaks, which resulted in several setbacks. In a press briefing last month, officials noted that the spacecraft has enough helium onboard for 70 hours, despite only needing seven. While they indicated that the vehicle could return to Earth if necessary, they also mentioned that they are not yet fully prepared for that return.
In the most recent update, NASA and Boeing suggested that a return flight could potentially occur at the end of this month; however, the timeline has since become less specific. The statement outlined that “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.”