The Boeing CST-100 Starliner crew received encouraging news regarding their return home. Earth-based testing of the spacecraft’s thrusters, which have left it stranded in space since early June, has now been completed. Boeing and NASA were waiting for these tests to conclude before starting plans for the spacecraft’s journey back to Earth.
An update from late 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 reviewing the data.” The main goal of these tests was to analyze thruster performance degradation to understand why some thrusters were inactive during flight and how reintroducing those thrusters might affect the remaining Crew Flight Test.
The term “de-selected” indicates that some thrusters ceased functioning. The tanks containing helium, which are essential for thruster operation, experienced leaks before and during the Starliner launch, resulting in several delays. During a recent press conference, officials disclosed that the spacecraft has 70 hours of helium onboard, despite needing only seven for its mission. While they stated earlier this month that the Starliner could return at any time if necessary, they also indicated that they were not ready for that to happen just yet.
In the latest update, NASA and Boeing mentioned that a return flight could occur by the end of this month. However, the timing has become less certain: “Boeing and NASA engineers will move forward with thruster disassembly and inspections while finalizing 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.”