The crew of the Boeing CST-100 Starliner has received encouraging news regarding its return to Earth. Ground testing of the spacecraft’s thrusters, which have kept it in orbit since early June, has now been completed. Boeing and NASA were awaiting the results of these tests to start planning the spacecraft’s homecoming.
A recent update 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 focusing on data reviews.” The goal of the test was to assess thruster degradation and understand why some thrusters were de-selected during flight, as well as the potential impact of returning those thrusters to service on the overall Crew Flight Test.
The term “de-selected” refers to some thrusters that failed to operate properly. Issues with the helium tanks that control the thrusters led to leaks before and during the Starliner’s launch, resulting in several delays. During a press conference last month, officials mentioned that the spacecraft has 70 hours of helium onboard, even though it only requires seven. While they suggested earlier this month that the craft could return immediately if required, they emphasized that they are not fully prepared for its return just yet.
In the latest update, NASA and Boeing indicated a possible return flight by the end of this month. However, the timeline has become less specific: “Boeing and NASA engineers will proceed with thruster disassembly and inspections, and finalize 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.”