The crew of the Boeing CST-100 Starliner has received some encouraging news regarding their return to Earth. Recent tests of the spacecraft’s thrusters, which have been inoperable since early June, have been successfully conducted on the ground. Boeing and NASA awaited the completion of these tests to begin planning for the Starliner’s return journey.
An update shared recently noted, “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.” The purpose of these tests was to examine thruster degradation, helping engineers understand the reasons behind some thrusters being deselected during flight, as well as assessing the potential implications of bringing those thrusters back into service.
“Deselected” indicates that certain thrusters ceased to function. Prior to and during the launch of the Starliner, there were issues with tanks containing helium, which is essential for controlling the thrusters, leading to successive delays in the mission. Official sources mentioned last month that the spacecraft holds 70 hours’ worth of helium, while only needing seven for its operations. Although they indicated that the Starliner could return home immediately if necessary, they also acknowledged that it is not yet fully prepared for such an event.
In the most recent announcement, NASA and Boeing stated that a possible return flight could occur at the end of this month. However, the timeline for the return has become less specific: “Boeing and NASA engineers will proceed with thruster disassembly and inspections and will advance towards finalizing flight rationale to support readiness reviews for Starliner’s anticipated return to Earth with commander Butch Wilmore and pilot Suni Williams in the coming weeks.”