The Boeing CST-100 Starliner crew has received some positive news regarding their upcoming return to Earth. Recently, the testing of the spacecraft’s thrusters, which has prevented it from returning since early June, was successfully completed. Both Boeing and NASA were awaiting these test results to start planning the spacecraft’s journey back.
An update provided last week confirmed that “ground testing of a Starliner Reaction Control System (RCS) thruster at White Sands Test Facility in New Mexico is complete, and teams are now reviewing the data.” The aim of the tests was to investigate the degradation of some thrusters that had failed during the flight and assess the potential impact of reactivating them on the overall Crew Flight Test.
The term “de-selected” refers to the thrusters that ceased functioning. Issues arose with the helium tanks controlling the thrusters, which were found to be leaking both prior to and during the Starliner launch, resulting in multiple delays. Officials indicated at a recent press conference that although the ship has 70 hours of helium onboard—well above the seven hours it requires—they are not yet fully prepared for it to return.
Previously, NASA and Boeing suggested that a return flight could occur at the end of this month. However, that timeline is now less certain. The latest statement notes that “Boeing and NASA engineers will proceed with thruster disassembly and inspections and will finalize flight rationale in preparation for readiness reviews for Starliner’s return to Earth with commander Butch Wilmore and pilot Suni Williams in the coming weeks.”