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 been completed. Boeing and NASA were waiting for these tests to finalize plans for the spacecraft’s homecoming.
An update provided last week stated, “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, helping the teams understand why some thrusters were marked as inoperative during the flight and the potential consequences of reactivating them.
The term “de-selected” refers to thrusters that ceased to function. During the Starliner’s launch, the helium tanks that manage the thrusters experienced leaks, resulting in several delays. Officials indicated last month that the spacecraft has 70 hours’ worth of helium on board, even though it only requires seven. While they stated earlier that the craft could return to Earth immediately if necessary, they clarified that they are not yet fully prepared for that return.
In the most recent update, NASA and Boeing indicated that a return flight might occur at the end of this month. However, the timeframe is now less certain: “Boeing and NASA engineers will proceed with thruster disassembly and inspections, and work towards finalizing flight rationale in support of readiness reviews for Starliner’s planned return to Earth with commander Butch Wilmore and pilot Suni Williams in the coming weeks.”