The Boeing CST-100 Starliner crew has received positive news regarding their impending return to Earth. Recently, ground tests of the spacecraft’s thrusters were completed, which have been inactive since early June. Boeing and NASA awaited these results to start planning the vehicle’s return journey.
An update released last week confirmed, “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 purpose of the tests was to assess the degradation of the thrusters to understand why certain thrusters were disabled during flight and to evaluate the potential impact of reactivating them on the overall Crew Flight Test.
The term “de-selected” refers to thrusters that malfunctioned. Prior to and during the Starliner launch, tanks that contain helium to control the thrusters experienced leaks, resulting in several delays. During a press conference last month, officials mentioned that the spacecraft has 70 hours’ worth of helium on board, despite requiring only seven. Although they stated earlier this month that the spacecraft could return immediately if necessary, they also indicated that they are not fully prepared for that.
At the last update, NASA and Boeing indicated that a return flight might occur by the end of this month. However, the timeline has now become less specific: “Boeing and NASA engineers will proceed with thruster disassembly and inspections and move forward with finalizing flight rationale in support of readiness reviews for Starliner’s nominal return to Earth with commander Butch Wilmore and pilot Suni Williams in the coming weeks.”