The Boeing CST-100 Starliner crew received promising news regarding their return home. Earth-based testing of the spacecraft’s thrusters, which have left it stranded in space since early June, has recently concluded. Boeing and NASA were waiting for these tests to finish before coordinating the spacecraft’s return trip.
An update released last week stated, “Ground testing of a Starliner Reaction Control System (RCS) thruster at the White Sands Test Facility in New Mexico is complete, and teams are now shifting their focus to data reviews.” The aim of the tests was to analyze the degradation of the thrusters to better understand why some were non-functional during flight and evaluate the implications of reactivating those thrusters for the remainder of the Crew Flight Test.
The term “de-selected” refers to thrusters that ceased operation. Helium tanks controlling the thrusters experienced leaks both before and during the Starliner launch, causing several delays. During a press conference last month, officials confirmed that the spacecraft has 70 hours’ worth of helium on board, far exceeding the seven hours required. While they stated earlier this month that the craft could return immediately if necessary, officials also noted that they are not yet fully prepared for that eventuality.
In the most recent update, NASA and Boeing indicated that a return flight could occur at the end of this month. However, the timeframe has since become less specific: “Boeing and NASA engineers will proceed with thruster disassembly and inspections and will work on finalizing flight rationale in preparation for readiness reviews for Starliner’s prompt return to Earth with commander Butch Wilmore and pilot Suni Williams in the coming weeks.”