The crew of the Boeing CST-100 Starliner has received encouraging news regarding their return journey to Earth. Recent ground tests on the spacecraft’s thrusters, which have left it in orbit since early June, have been successfully completed. Boeing and NASA were awaiting the results of these tests before making plans for the craft’s return.
An update provided late 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 turning their attention to data reviews.” The primary aim of the testing was to understand the degradation of some thrusters, which led to their de-selection during flight, and to evaluate any potential impact of reactivating them on the upcoming Crew Flight Test.
The term “de-selected” refers to thrusters that ceased functioning. Prior to and during the Starliner launch, there were issues with helium tanks that control the thrusters, resulting in several delays. At a press conference last month, officials indicated that the spacecraft was equipped with 70 hours’ worth of helium, even though it only requires seven. They noted that while the craft could technically return to Earth immediately, they are not ready for it to do so just yet.
In their latest update, NASA and Boeing indicated that a return flight might occur by the end of this month. However, the timeline has become less definitive: “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.”