The Boeing CST-100 Starliner crew received positive news regarding their return to Earth. Recent ground tests on the spacecraft’s thrusters, which have left it in orbit since early June, have been successfully completed. Both Boeing and NASA were awaiting the conclusion of these tests before initiating plans for the spacecraft’s return journey.
The update from last week confirmed that ground testing of a Starliner Reaction Control System (RCS) thruster at the White Sands Test Facility in New Mexico has been completed, and teams are now focused on reviewing the data collected. The purpose of the test was to examine thruster degradation, which would help engineers understand why some thrusters were deactivated during flight and assess the implications of potentially reactivating those thrusters for the Crew Flight Test.
The term “de-selected” refers to certain thrusters that became inoperative. Issues with the helium tanks that control these thrusters had resulted in leaks prior to and during the Starliner’s launch, causing several delays. Officials mentioned at a press conference last month that the spacecraft has 70 hours of helium onboard, although only seven hours are necessary for operation. They indicated that while the craft could technically return to Earth now, they are not yet fully prepared for that outcome.
In their latest update, NASA and Boeing stated that a return flight might be possible towards the end of this month. However, the timeline has become less specific: “Boeing and NASA engineers will engage in thruster disassembly and inspections, and continue finalizing flight plans to support readiness reviews for Starliner’s anticipated return to Earth with commander Butch Wilmore and pilot Suni Williams in the upcoming weeks.”