The Boeing CST-100 Starliner crew received encouraging news regarding their return to Earth. Recent ground testing of the spacecraft’s thrusters, which have left it in orbit since early June, has been successfully completed. Boeing and NASA were awaiting the outcome of these tests before initiating plans for the spacecraft’s return journey.
An update shared late last week noted, “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 goal of the testing was to examine thruster degradation, enabling teams to better understand the reasons behind the in-flight failure of some thrusters and assess the potential impact of reactivating them on the overall Crew Flight Test.
Officials indicated that some thrusters were “de-selected,” meaning they ceased functioning. There were issues with the helium tanks that control the thrusters, which experienced leaks both before and during the Starliner’s launch, causing several delays. At a press conference last month, officials mentioned that the spacecraft is equipped with 70 hours’ worth of helium, despite only needing seven. While they previously stated that the spacecraft could return to Earth immediately if necessary, they clarified that they are not yet prepared for that scenario.
In their latest update, NASA and Boeing suggested that a return flight might occur by the end of this month. However, the timeline has since become less defined: “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.”