The Boeing CST-100 Starliner crew has received positive news regarding their return to Earth. Testing of the spacecraft’s thrusters, which have prevented it from coming back since early June, has recently concluded. Both Boeing and NASA were awaiting these results to begin planning the craft’s return journey.
An update released last week stated, “Ground testing of a Starliner Reaction Control System (RCS) thruster at the White Sands Test Facility in New Mexico is complete, and teams are now focused on data analysis.” The primary goal of the testing was to observe any degradation in thruster performance, which would help teams understand why some thrusters were inactive during flight and assess the implications of reactivating them on the upcoming Crew Flight Test.
The term “de-selected” refers to thrusters that malfunctioned. Prior to and during the Starliner’s launch, the helium tanks responsible for controlling the thrusters experienced leaks, causing several delays. Officials noted last month that the spacecraft has 70 hours of helium available, despite only needing seven for the flight. While they indicated earlier this month that the Starliner could return immediately if necessary, they also mention that they are not entirely prepared for that eventuality.
In the latest update, NASA and Boeing suggested that a return flight could happen at the end of this month. However, the timeframe has since become less specific: “Boeing and NASA engineers will proceed with the disassembly and inspection of the thrusters while finalizing the flight rationale in preparation for readiness reviews for Starliner’s planned return to Earth with commander Butch Wilmore and pilot Suni Williams in the coming weeks.”