The crew of the Boeing CST-100 Starliner has received positive news regarding their eventual return to Earth. Recent ground tests of the spacecraft’s thrusters, which have kept it in orbit since early June, have been successfully completed. Boeing and NASA were awaiting the conclusion of these tests to start organizing the spacecraft’s re-entry plans.
An update released last week confirmed, “Ground testing of a Starliner Reaction Control System (RCS) thruster at White Sands Test Facility in New Mexico is complete, and teams are now turning their attention to data reviews.” The aim of these tests was to observe any degradation in the thrusters to understand why some were rendered non-operational during flight and to assess the potential impacts of reactivating those thrusters on the rest of the Crew Flight Test.
Some thrusters were described as “de-selected,” meaning they ceased to function. Issues arose with the helium tanks that control the thrusters, which experienced leaks before and during the Starliner launch, causing multiple delays. Previously, officials noted the spacecraft has 70 hours’ worth of helium onboard, despite only requiring seven for its operations. While they indicated the Starliner could return to Earth immediately if necessary, they also stated that it is not yet fully prepared for re-entry.
In their last update, NASA and Boeing pointed to the possibility of a return flight at the end of this month. However, the timeline has now become less specific: “Boeing and NASA engineers will proceed with thruster disassembly and inspections, as well as finalize flight rationale to support readiness reviews for Starliner’s planned return to Earth with commander Butch Wilmore and pilot Suni Williams in the coming weeks.”