The Boeing CST-100 Starliner crew has received positive news regarding their impending return to Earth. Earth-based tests on the spacecraft’s thrusters have been successfully completed, which had kept it in orbit since early June. Boeing and NASA were awaiting the outcome of these tests before starting to plan the return journey.
An update from last week announced, “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 data reviews.” The aim of the tests was to assess thruster performance degradation, helping teams understand why some thrusters were inactive during flight and the implications of reinstating them for the spacecraft’s overall performance during the Crew Flight Test.
The term “de-selected” refers to the thrusters that malfunctioned. Prior to and during the Starliner launch, helium tanks that run the thrusters experienced leaks, causing various delays. Officials mentioned last month that the vessel is equipped with 70 hours of helium, although it only requires seven. While they indicated earlier this month that the craft could return if necessary, they also noted that they are not fully prepared for its departure just yet.
In the most recent update, NASA and Boeing mentioned that a return flight might occur at the end of this month. However, this window is now less specific: “Boeing and NASA engineers will proceed with thruster disassembly and inspections, and continue working on finalizing 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.”