The Boeing CST-100 Starliner crew has received encouraging news regarding their return to Earth. Recently, ground tests of the spacecraft’s thrusters, which have kept it in space since early June, were successfully completed. Boeing and NASA had been awaiting the conclusion of these tests to initiate plans for the vehicle’s return journey.
An update released late last week confirmed, “Ground testing of a Starliner Reaction Control System (RCS) thruster at White Sands Test Facility in New Mexico is complete, and teams are now turning their attention to data reviews.” The primary goal of the test was to evaluate thruster degradation, which would help identify the reasons behind the in-flight failure of some thrusters and assess any implications of reactivating them for the remaining Crew Flight Test.
The term “de-selected” indicates that certain thrusters became non-operational. Prior to and during the Starliner launch, helium tanks that regulate the thrusters were found to be leaking, causing several delays. Last month, officials noted that the spacecraft was equipped with 70 hours of helium, despite only needing seven. While they mentioned earlier this month that the spacecraft could return home if necessary, they indicated that it was not quite ready for that step.
According to the latest update, NASA and Boeing suggested that a return flight could potentially happen at the end of this month. However, the timeframe has become less certain: “Boeing and NASA engineers will proceed with thruster disassembly and inspections and move forward with finalizing flight rationale in support of readiness reviews for Starliner’s nominal return to Earth with commander Butch Wilmore and pilot Suni Williams in the coming weeks.”