The crew of the Boeing CST-100 Starliner has received encouraging news regarding their return to Earth. Ground testing of the spacecraft’s thrusters, which have left it in orbit since early June, has now been successfully concluded. Boeing and NASA had been waiting for these tests to be completed before making plans for the spacecraft’s homecoming.
An update provided late last week 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 turning their attention to data reviews.” This testing aimed to assess thruster performance issues, particularly why some thrusters were not functional during flight and to understand the implications of restoring them to operation for the spacecraft’s upcoming Crew Flight Test.
Officials explained that “de-selected” refers to thrusters that ceased operations due to issues with the helium tanks, which were leaking prior to and during the launch. These problems resulted in multiple delays. Although the craft is equipped with approximately 70 hours of helium, it only requires seven for operation. Earlier this month, officials indicated that while the Starliner could return home immediately if necessary, they are not yet prepared for that eventuality.
NASA and Boeing previously indicated that a return flight could occur at the end of this month. However, the timeline has become less specific: “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.”