The crew of the Boeing CST-100 Starliner has received some positive news regarding its eventual return to Earth. Recent tests of the spacecraft’s thrusters, which have kept it in space since early June, have been concluded. Boeing and NASA had been awaiting the completion of these tests to begin planning for the spacecraft’s homecoming.
An update from 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 focused on reviewing the data.” The goal of the tests was to understand the degradation of some thrusters that were not operational during flight and to assess any implications of returning those thrusters to service on the upcoming Crew Flight Test.
The term “de-selected” refers to thrusters that ceased functioning. Before and during the Starliner launch, tanks holding the helium for thruster control experienced leaks, resulting in multiple delays. Officials indicated last month that the spacecraft has enough helium for 70 hours of operation, even though only seven hours are needed. While they stated earlier this month that the craft could return if necessary, they aren’t fully prepared for that to happen just yet.
In the most recent update, NASA and Boeing mentioned that a return flight might happen by the end of this month. However, that timeline has since become more uncertain: “Boeing and NASA engineers will proceed with thruster disassembly and inspections and work on finalizing flight rationale to support readiness reviews for Starliner’s planned return to Earth with commander Butch Wilmore and pilot Suni Williams in the coming weeks.”