The crew of the Boeing CST-100 Starliner has received some promising news regarding their return to Earth. Ground tests of the spacecraft’s thrusters, which have been stranded in space since early June, have recently been completed. Boeing and NASA had been waiting for these tests to conclude before planning the spacecraft’s journey home.
An update released late 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 focused on reviewing the data.” The aim of the test was to analyze thruster performance degradation to understand why certain thrusters were not used during flight and to evaluate the implications of reinstating those thrusters for the upcoming Crew Flight Test.
The term “de-selected” refers to thrusters that failed to operate. Prior to and during the Starliner launch, helium tanks, which supply the thrusters, experienced leaks, causing several delays. Officials indicated last month that the Starliner currently carries 70 hours of helium on board, significantly more than the seven hours it requires. Although they mentioned that the spacecraft could technically return to Earth at any moment, readiness for an immediate return is still not in place.
The last communication from NASA and Boeing suggested a potential return flight at the end of this month. However, that timeframe has since become less defined: “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 planned return to Earth with commander Butch Wilmore and pilot Suni Williams in the coming weeks.”