The Boeing CST-100 Starliner crew has received encouraging news regarding their impending return to Earth. Recent ground testing of the spacecraft’s thrusters, which have kept it in space since early June, has now concluded. Boeing and NASA were waiting for these tests to determine the plans for the spacecraft’s return trip.
An update issued late last week confirmed the completion of ground testing for a Starliner Reaction Control System (RCS) thruster at the White Sands Test Facility in New Mexico. The focus now shifts to data review. The aim of the test was to observe any degradation of the thrusters to understand why some were deactivated during flight and the potential effects of reactivating them on the overall Crew Flight Test.
The term “de-selected” refers to some thrusters ceasing to function. Issues arose with the helium tanks controlling these thrusters, which were found to be leaking prior to and during the Starliner’s launch, causing several delays. Officials noted that the spacecraft carries 70 hours’ worth of helium, although it only requires seven hours. While they stated earlier this month that the spacecraft could return immediately if necessary, they are not yet fully prepared for that scenario.
In the most recent update, NASA and Boeing indicated that a return flight could occur at the end of this month. However, the timeline is now less precise: “Boeing and NASA engineers will proceed with thruster disassembly and inspections, and continue finalizing the 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.”