The Boeing CST-100 Starliner crew has received promising news regarding their eventual return to Earth. Recent ground testing of the spacecraft’s thrusters, which have left it in orbit since early June, has been successfully completed. Boeing and NASA have been awaiting these results to begin planning for the spacecraft’s return journey.
An update released last week confirmed that the ground testing of a Starliner Reaction Control System (RCS) thruster at the White Sands Test Facility in New Mexico has concluded, and teams are now focused on reviewing the data. The aim of the tests was to assess thruster performance degradation to understand why some thrusters were deactivated during flight and to evaluate the potential implications of reactivating them for the upcoming Crew Flight Test.
The term “de-selected” refers to those thrusters that became non-functional. Prior to and during the Starliner’s launch, the helium tanks that govern the thrusters experienced leaks, resulting in several delays. Officials mentioned last month that the spacecraft has 70 hours of helium onboard, while only seven hours are necessary for its operation. Although they indicated earlier this month that the craft could return immediately if required, they also acknowledged that they are not fully prepared for that outcome.
In their latest update, NASA and Boeing suggested that a return flight may occur by the end of this month. However, the timeline has become less specific, stating that “Boeing and NASA engineers will proceed with thruster disassembly and inspections, and will move forward with finalizing 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.”