The crew of the Boeing CST-100 Starliner has received encouraging news regarding its imminent return to Earth. Recent tests on the spacecraft’s thrusters, which have kept it in space since early June, have been successfully completed. Boeing and NASA were awaiting the results of these tests before they could start planning the spacecraft’s homecoming.
“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,” an update issued late last week stated. The tests aimed to assess thruster performance issues, particularly to understand why some thrusters failed during the flight and the potential effects of reactivating them.
The term “de-selected” refers to thrusters that ceased functioning. Prior to and during the Starliner launch, the helium tanks that control the thrusters experienced leaks, resulting in several postponements. Officials mentioned that the spacecraft has 70 hours’ worth of helium available, whereas it only requires approximately seven hours. Although they indicated earlier this month that the spacecraft could return to Earth anytime if necessary, they also noted they are not yet fully prepared for that scenario.
In their last update, NASA and Boeing suggested that a return flight might occur at the end of this month. However, the timeline has since become less specific: “Boeing and NASA engineers will proceed with thruster disassembly and inspections and work towards 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.”