The Boeing CST-100 Starliner spacecraft has received some promising news regarding its return to Earth. Recently completed ground testing of the spacecraft’s thrusters, which have left it in orbit since early June, paves the way for Boeing and NASA to begin planning its homeward journey.
An update released last week announced, “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 purpose of these tests was to analyze thruster performance and understand the reasons for the in-flight failure of some thrusters, as well as to assess the implications of potentially reactivating those thrusters for the upcoming Crew Flight Test.
Some thrusters were “de-selected,” indicating they became nonfunctional during flight. This issue stemmed from leaks in the helium tanks that control the thrusters, resulting in several delays. Officials noted last month that the Starliner has a supply of helium that far exceeds its needs, with 70 hours available despite only requiring seven. Although they indicated earlier this month that the spacecraft could return to Earth immediately if necessary, it appears they are not fully prepared to proceed with that plan just yet.
In their latest update, NASA and Boeing suggested that a return flight could happen at the end of this month, although the timeline has become less specific. The update mentioned, “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.”