The crew of the Boeing CST-100 Starliner has received promising news regarding their return to Earth. Recent ground tests of the spacecraft’s thrusters, which have left it in orbit since early June, have now been completed. Boeing and NASA were awaiting the results of these tests before planning the Starliner’s homecoming.
An update shared last week confirmed that testing of a Starliner Reaction Control System (RCS) thruster at the White Sands Test Facility in New Mexico had concluded, and teams are now focusing on data analysis. The purpose of the tests was to assess thruster performance, particularly why some units were deactivated during flight and to evaluate the potential implications of reactivating those thrusters for the upcoming Crew Flight Test.
The term “de-selected” refers to thrusters that ceased functioning. Issues arose from leaks in the helium tanks that control the thrusters both before and during the launch, resulting in multiple delays. During a press briefing last month, officials indicated that the Starliner possesses 70 hours of helium on board, although it only requires seven hours for its operations. They mentioned earlier this month that the spacecraft could return immediately if necessary, but indicated that they were not yet fully prepared for its homecoming.
In the latest update, NASA and Boeing suggested that a return flight could occur by the end of this month. However, the timing now appears less certain: “Boeing and NASA engineers will continue with thruster disassembly and inspections, and proceed to finalize flight rationale in preparation for readiness reviews for Starliner’s planned return to Earth with commander Butch Wilmore and pilot Suni Williams in the upcoming weeks.”