The Boeing CST-100 Starliner crew has received encouraging news regarding its eventual return to Earth. Recent ground testing of the spacecraft’s thrusters, which have kept it in orbit since early June, has been completed. Boeing and NASA were awaiting the completion of these tests before they could begin planning the vessel’s return journey.
An update released last week stated, “Ground testing of a Starliner Reaction Control System (RCS) thruster at White Sands Test Facility in New Mexico is complete, and teams are now focusing on data reviews.” The purpose of the testing was to examine thruster performance and degradation to better understand why some thrusters lost functionality during the flight and to evaluate the potential impact of reactivating them on the overall Crew Flight Test.
Some thrusters were “de-selected” due to malfunctioning, stemming from leaks in the helium tanks that control these thrusters prior to and during the launch. Officials noted that the Starliner has 70 hours of helium onboard, although only seven are required for the mission. They mentioned earlier this month that while the spacecraft could theoretically return to Earth at any time, they prefer to ensure that everything is fully prepared.
In the latest communication, NASA and Boeing indicated that a return flight might occur at the end of this month, but the timeline has since become less specific. “Boeing and NASA engineers will proceed with thruster disassembly and inspections and continue to finalize flight rationale to support readiness reviews for Starliner’s planned return to Earth with commander Butch Wilmore and pilot Suni Williams in the upcoming weeks.”