The crew of the Boeing CST-100 Starliner has received encouraging news regarding their return to Earth. Earthbound testing of the spacecraft’s thrusters, which have kept it in space since early June, has recently been completed. Boeing and NASA were waiting for these tests to finish before planning the vessel’s homecoming.
Last week, an update confirmed that “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 goal of the testing was to observe thruster performance issues that had caused some thrusters to be “de-selected” during the flight, which impacted their operational capacity.
“De-selected” refers to thrusters that failed to function. Prior to and during the Starliner launch, there were leaks in the helium tanks that control the thrusters, resulting in multiple delays. Officials mentioned at a press conference last month that the spacecraft has 70 hours’ worth of helium on board, despite only needing seven hours for operation. While they indicated earlier this month that the craft could return immediately if necessary, they have also conveyed that they are not fully prepared for that event yet.
In the most recent statement, NASA and Boeing mentioned that a return flight could be possible by the end of this month. However, the timeframe has become less specific. They stated, “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.”