The Boeing CST-100 Starliner crew has received encouraging news regarding the spacecraft’s return to Earth. Ground testing for the spacecraft’s thrusters, which have left it stranded in space since early June, has now been completed. Boeing and NASA had been awaiting these tests to begin planning for the vehicle’s homecoming.
An update from last week confirmed that “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 goal of the tests was to assess thruster degradation and understand why certain thrusters failed during flight, as well as the potential impact of reactivating them on the upcoming Crew Flight Test.
The term “de-selected” refers to thrusters that ceased functioning. The helium tanks that control the thrusters experienced leaks before and during the Starliner’s launch, causing several delays. Officials noted that while the spacecraft has 70 hours’ worth of helium onboard—significantly more than the seven hours required—it is not yet ready for a return home, even though they stated earlier this month that it could land if necessary.
In the most recent update, NASA and Boeing indicated that a return flight might occur at the end of this month. However, the timeline has since become less certain: “Boeing and NASA engineers will move forward with thruster disassembly and inspections and finalize flight rationale in preparation for readiness reviews for Starliner’s planned return to Earth with commander Butch Wilmore and pilot Suni Williams in the upcoming weeks.”