The Boeing CST-100 Starliner crew recently received encouraging news regarding their return to Earth. Testing of the spacecraft’s thrusters, which have kept it in space since early June, has been successfully completed. Boeing and NASA had been awaiting the results of these tests to start planning for the spacecraft’s homecoming.
An update from late last week stated, “Ground testing of a Starliner Reaction Control System (RCS) thruster at the White Sands Test Facility in New Mexico is complete, and teams are now focusing on data reviews.” The primary goal of the test was to assess thruster degradation to better understand why some thrusters were not operational during flight and to evaluate the potential impacts of reactivating those thrusters on the Crew Flight Test.
Some thrusters had to be “de-selected,” meaning they ceased functioning. Issues with the helium tanks that control the thrusters led to leaks both before and during the launch, resulting in multiple delays. Officials noted that the spacecraft has 70 hours of helium onboard, well beyond the seven hours it requires. While they mentioned earlier in the month that the craft could return immediately if necessary, they also indicated that preparations for that return were still underway.
NASA and Boeing had initially projected a return flight could happen by the end of this month, but now the timeline is less certain. The latest update states, “Boeing and NASA engineers will proceed with thruster disassembly and inspections, and will move forward with finalizing flight rationale to support readiness reviews for Starliner’s planned return to Earth with commander Butch Wilmore and pilot Suni Williams in the upcoming weeks.”