The Boeing CST-100 Starliner crew has received positive news regarding the spacecraft’s return to Earth. Recently completed ground tests of the vessel’s thrusters, which have kept it in space since early June, pave the way for preparations for its homecoming. Boeing and NASA had been awaiting these tests before making plans for the spacecraft’s return journey.
An update provided last week noted, “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 primary goal of the tests was to monitor thruster degradation to better understand why some thrusters were inactive during flight and to assess the implications of reactivating them.
When officials referred to “de-selected” thrusters, they indicated that some had malfunctioned. Prior to and during the Starliner’s launch, the helium tanks that manage the thrusters were experiencing leaks, resulting in several delays. During a press conference last month, it was mentioned that the spacecraft has 70 hours’ worth of helium, despite only needing seven for its operations. Although officials stated earlier this month that the Starliner could return immediately if necessary, they also indicated readiness for that scenario was still pending.
In their latest update, NASA and Boeing suggested a potential return flight might occur at the end of the month. However, the timeline has become less specific: “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.”