The crew of the Boeing CST-100 Starliner has received encouraging news regarding its return to Earth. Recently, ground testing of the spacecraft’s thrusters was completed, which had left it in orbit since early June. Boeing and NASA were awaiting the conclusion of these tests before finalizing the plans for the vessel’s return trip.
An update provided last week indicated that the ground testing for a Starliner Reaction Control System (RCS) thruster at the White Sands Test Facility in New Mexico is now finished, and the teams are beginning to review the data. The main goal of the tests was to assess thruster performance degradation to understand why some thrusters were deactivated during the flight and to evaluate the potential impacts of reactivating those thrusters on the upcoming Crew Flight Test.
The term “de-selected” refers to thrusters that failed to operate. Prior to and during the Starliner launch, leaks were discovered in the helium tanks that control the thrusters, causing several delays. Officials mentioned last month that the spacecraft is equipped with 70 hours’ worth of helium, even though it typically requires only seven hours. While they stated earlier this month that the craft could return immediately if necessary, they also confirmed they are not yet fully prepared for that scenario.
In the latest communication, NASA and Boeing suggested that a return flight could happen at the end of this month. However, the timeline has since become less specific: “Boeing and NASA engineers will move forward with the disassembly and inspections of the thrusters, as well as finalizing the flight rationale in preparation for readiness reviews for Starliner’s planned return to Earth with commander Butch Wilmore and pilot Suni Williams in the coming weeks.”