The crew of the Boeing CST-100 Starliner received promising news regarding their eventual return to Earth. Recent successful ground tests of the spacecraft’s thrusters, which have kept it in orbit since early June, have been completed. Boeing and NASA were waiting for these tests to finish before making plans for the spacecraft’s return journey.
According to an update released late last week, “Ground testing of a Starliner Reaction Control System (RCS) thruster at White Sands Test Facility in New Mexico is complete, and teams are now focusing on data reviews.” The goal of the tests was to assess thruster degradation, providing insight into why some thrusters were inactive during flight and determining the implications of potentially restoring them to service for the upcoming Crew Flight Test.
The term “de-selected” refers to thrusters that stopped functioning. Prior to and during the Starliner’s launch, helium tanks that control the thrusters experienced leaks, causing several delays. Officials indicated last month that, although the spacecraft has 70 hours’ worth of helium stored onboard—significantly more than the seven hours it needs—it is not yet fully prepared for a return.
The most recent communication from NASA and Boeing suggested that a return flight could occur at the end of this month, but the timeline has since become less specific. The teams will continue with the disassembly and inspection of the thrusters and will work on finalizing the flight rationale to support readiness reviews for Starliner’s safe return to Earth, which will include commander Butch Wilmore and pilot Suni Williams in the coming weeks.