The Boeing CST-100 Starliner is showing promising signs for its return to Earth as the crew recently completed ground testing of the spacecraft’s thrusters, which had left it awaiting re-entry since early June. Boeing and NASA had been postponing plans for the spacecraft’s homecoming until these critical tests were finished.
An update provided late last week confirmed the successful completion of tests on a Starliner Reaction Control System (RCS) thruster at the White Sands Test Facility in New Mexico. Teams will now focus on reviewing the data collected during the tests. The primary objective was to assess thruster degradation, allowing engineers to determine the reasons behind the failure of some thrusters during flight and the potential implications of returning them to service.
Some thrusters were “de-selected” during the mission, meaning they ceased functioning. This issue stemmed from leaks in the helium tanks that control the thrusters, causing multiple delays prior to and during the Starliner’s launch. Despite having 70 hours’ worth of helium onboard, far exceeding the seven hours needed for operation, officials indicated that while the craft could technically return now, they are not quite ready for it to do so.
In their last update, NASA and Boeing suggested a possible return flight by the end of the month. However, the timeline has since 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,” the statement noted.