The crew of the Boeing CST-100 Starliner has received encouraging news regarding their return to Earth. Recently completed ground testing of the spacecraft’s thrusters, which have left it in orbit since early June, marks a significant step forward. Boeing and NASA were awaiting the completion of these tests to start planning the spacecraft’s homeward journey.
An update released late 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 data analysis.” The objective of the tests was to observe any degradation in the thrusters to gain insight into the reasons some were rendered inoperable during flight and to assess whether reactivating them would affect the overall flight performance.
The term “de-selected” refers to some thrusters that became nonfunctional. Prior to and during the Starliner launch, leaks in the helium tanks that control the thrusters contributed to multiple delays. At a press conference last month, officials confirmed that the spacecraft has 70 hours’ worth of helium on board, despite only requiring seven. Although they indicated earlier this month that the craft could return now if necessary, they also mentioned they are not fully prepared for it to do so.
According to the latest update from NASA and Boeing, they mentioned a possible return flight by the end of this month, but the timeline has since become less specific: “Boeing and NASA engineers will begin thruster disassembly and inspections, and work towards finalizing flight rationale to support readiness reviews for Starliner’s anticipated return to Earth with commander Butch Wilmore and pilot Suni Williams in the upcoming weeks.”