The Boeing CST-100 Starliner crew has received promising news regarding their return to Earth. The successful completion of ground testing for the spacecraft’s thrusters, which have left it stranded in space since early June, paves the way for planning its homecoming.
An update released last week confirmed, “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 primary aim of these tests was to assess thruster degradation to understand the issues that led to some thrusters being disabled during flight and to evaluate the potential implications of returning those thrusters to service for the Crew Flight Test.
When officials referred to “de-selected” thrusters, they indicated that certain thrusters had ceased functioning. Prior to and during the Starliner launch, the helium tanks responsible for controlling the thrusters experienced leaks, resulting in several delays. During a press conference last month, it was noted that the spacecraft retains 70 hours’ worth of helium even though it only requires seven. Although earlier statements indicated the craft could return immediately if necessary, officials mentioned they are not fully prepared for that eventuality.
At their most recent update, NASA and Boeing suggested a return flight could occur by the end of this month. However, the timeline has now become less specific: “Boeing and NASA engineers will proceed with thruster disassembly and inspections, and advance towards finalizing flight rationale in support of readiness reviews for Starliner’s planned return to Earth with commander Butch Wilmore and pilot Suni Williams in the coming weeks.”