The crew of the Boeing CST-100 Starliner has received positive news regarding their eventual return to Earth. Testing on the spacecraft’s thrusters, which has kept it in orbit since early June, was successfully completed. Boeing and NASA were waiting for these tests to finish before planning the spacecraft’s return journey.
An update from last week announced, “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 focusing on reviewing the data.” The objective of these tests was to investigate the degradation of certain thrusters that were disabled during the flight, to better understand their performance and the potential impacts of reactivating them for the upcoming Crew Flight Test.
The term “de-selected” refers to some thrusters that ceased functioning. There were issues with tanks containing helium, which controls the thrusters, leaking both prior to and during the Starliner’s launch, resulting in several delays. Officials noted that the spacecraft carries 70 hours’ worth of helium, even though it only requires seven. While they indicated earlier this month that the Starliner could return immediately if necessary, they mentioned that they are not yet fully prepared for that scenario.
In their last update, NASA and Boeing anticipated a possible return flight by the end of this month. However, the timeline has become less specific now: “Boeing and NASA engineers will proceed with thruster disassembly and inspections, and work to finalize flight rationale to support readiness reviews for Starliner’s planned return to Earth with commander Butch Wilmore and pilot Suni Williams in the upcoming weeks.”