The crew of the Boeing CST-100 Starliner received encouraging news regarding their return to Earth. Recently, ground testing of the spacecraft’s thrusters, which have left it stranded in space since early June, was completed. Boeing and NASA had been awaiting the outcomes of these tests to commence planning the vessel’s journey back home.
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 turning their attention to data reviews.” The goal of the testing was to examine thruster degradation to better understand why certain thrusters were inoperable during flight, and to assess any potential impacts of reactivating those thrusters for the Crew Flight Test.
The term “de-selected” refers to the thrusters that stopped functioning. There were issues with the helium tanks controlling the thrusters, which experienced leaks both before and during the Starliner’s launch, causing several delays. Officials indicated that the spacecraft has 70 hours’ worth of helium on board, despite only requiring seven for its mission. They previously noted that while the Starliner could technically return immediately if necessary, they are not fully prepared for that scenario.
In their latest update, NASA and Boeing suggested that a return flight could occur at the end of this month, although the timing has become less specific. “Boeing and NASA engineers will proceed with thruster disassembly and inspections and will 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.”