The crew of the Boeing CST-100 Starliner received encouraging news regarding their return to Earth. Recent ground testing of the spacecraft’s thrusters, which have kept the Starliner in orbit since early June, has been completed. Boeing and NASA were awaiting the results of these tests to start planning the spacecraft’s return.
According to an update from last week, “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 reviewing the data.” The objective of the tests was to understand the degradation of the thrusters, particularly why some were deactivated during flight and the potential effects of reintegrating them for the remainder of the Crew Flight Test.
“De-selected” refers to the thrusters that failed to operate. Prior to and during the Starliner launch, helium tanks controlling the thrusters experienced leaks, causing several delays. Officials noted in a recent press conference that the spacecraft carries 70 hours’ worth of helium, despite only requiring seven. While they earlier stated that the Starliner could return immediately if necessary, they clarified that they were not entirely prepared for that eventuality.
In their latest update, NASA and Boeing indicated that a return flight could be possible by the end of this month. However, the timeline has become less specific: “Boeing and NASA engineers will proceed with thruster disassembly and inspections, and will work towards finalizing flight rationale for readiness reviews in support of Starliner’s planned return to Earth with commander Butch Wilmore and pilot Suni Williams in the upcoming weeks.”