The team behind the Boeing CST-100 Starliner has received some positive news regarding its return to Earth. Recently, Earth-based testing of the spacecraft’s thrusters was completed, which had been a factor in keeping it in orbit since early June. Boeing and NASA were awaiting these test results to start planning the vehicle’s homeward journey.
An update released late last week stated, “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 analysis.” This testing aimed to identify any degradation in the thrusters, assisting teams in understanding the reasons behind the in-flight failure of some thrusters and evaluating the implications of returning them to service.
The term “de-selected” refers to the thrusters that ceased to function. Prior to and during the Starliner’s launch, helium tanks that power these thrusters were found to be leaking, contributing to multiple delays. Officials mentioned last month that the spacecraft contains 70 hours’ worth of helium, despite only requiring seven for its operations. While they stated that the craft could return now if necessary, they also indicated that it is not yet fully prepared for re-entry.
In their most recent update, NASA and Boeing indicated that a return flight might occur by the end of this month. However, the timeline has shifted to a more uncertain prospect: “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.”