The Boeing CST-100 Starliner crew received encouraging news regarding their return to Earth. Testing of the spacecraft’s thrusters, which has kept it in orbit since early June, has recently concluded. Boeing and NASA were awaiting the completion of these tests to begin planning the vessel’s return journey.
An update shared last week indicated, “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 reviewing the data.” The testing aimed to examine thruster degradation to better understand why some thrusters were de-selected during flight and to assess the potential implications of reactivating those thrusters on the overall Crew Flight Test.
“De-selected” refers to some thrusters that stopped functioning. The helium tanks that control these thrusters were leaking before and during the Starliner’s launch, which resulted in several delays. Officials noted in a press conference last month that the spacecraft has 70 hours’ worth of helium onboard, despite only requiring seven hours. While they stated earlier this month that the Starliner could return to Earth if necessary, they also indicated that they were not fully prepared for that outcome.
NASA and Boeing previously mentioned that a return flight might occur at the end of this month. However, the timeline has become less specific: “Boeing and NASA engineers will proceed with thruster disassembly and inspections, and 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.”