The crew of the Boeing CST-100 Starliner has received promising updates regarding its return to Earth. The ground testing of the spacecraft’s thrusters, which have left it in space since early June, has recently been completed. Boeing and NASA were awaiting the outcome of these tests to initiate plans for the spacecraft’s journey back home.
An update released last week indicated, “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 testing aimed to examine thruster degradation, helping engineers understand why some thrusters were inactive during the flight and what implications restoring those thrusters could have on the remainder of the Crew Flight Test.
The term “de-selected” refers to thrusters that ceased functioning. Prior to and during the Starliner’s launch, there were leaks from the helium tanks that manage the thrusters, resulting in several delays. Officials stated last month that the spacecraft has 70 hours’ worth of helium onboard, although it only requires seven. While it was mentioned earlier this month that the spacecraft could return immediately if necessary, the team noted they are not yet fully prepared for that transition.
In their latest communication, NASA and Boeing noted that a return flight may occur by the end of this month. However, the timeline has since become more uncertain: “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.”