The Boeing CST-100 Starliner crew received encouraging news regarding their return to Earth. Recent ground testing of the spacecraft’s thrusters, which have left it in space since early June, has now been finished. Both Boeing and NASA awaited the completion of these tests to initiate plans for the ship’s return journey.
An update released 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 purpose of the tests was to observe any degradation in the thrusters and to gain insights into why some of them were de-selected during flight, as well as the potential effects of restoring those thrusters to service.
The term “de-selected” refers to certain thrusters that failed to operate effectively. Prior to and during the Starliner’s launch, there were leaks in the helium tanks responsible for controlling the thrusters, contributing to several delays. During a press conference last month, officials announced that the spacecraft has 70 hours’ worth of helium onboard, although it only requires seven hours for its operations. While they mentioned earlier this month that the craft could return at any time if necessary, they also indicated that they are not fully prepared for that.
At the last update from NASA and Boeing, a return flight was anticipated to occur at the end of this month. However, the timeline has since become a bit less specific: “Boeing and NASA engineers will move forward with thruster disassembly and inspections, and will continue finalizing flight rationale to support readiness reviews for the Starliner’s planned return to Earth with commander Butch Wilmore and pilot Suni Williams in the upcoming weeks.”