The Boeing CST-100 Starliner crew received encouraging news regarding its return to Earth. Recently, successful ground testing of the spacecraft’s thrusters was completed, which had been keeping it in orbit since early June. Boeing and NASA were waiting for these tests to finalize plans for the vessel’s homecoming.
An update shared last week announced, “Ground testing of a Starliner Reaction Control System (RCS) thruster at White Sands Test Facility in New Mexico is complete, and teams are now focused on reviewing the data.” The main goal of these tests was to assess thruster degradation and understand why certain thrusters were deactivated during flight, as well as to evaluate the implications of reactivating them on the rest of the Crew Flight Test.
The term “de-selected” refers to some thrusters that ceased functioning. Prior to and during the Starliner’s launch, the helium tanks that regulate the thrusters were found to have leaks, resulting in multiple delays. During a press conference last month, officials stated that the spacecraft carries 70 hours’ worth of helium, despite needing only seven. While they indicated earlier this month that the spacecraft could return immediately if necessary, they also pointed out that they are not fully prepared for that eventuality.
In their latest update, NASA and Boeing mentioned that a return flight might occur at the end of this month, but the timeline has since become less clear. “Boeing and NASA engineers will proceed with thruster disassembly and inspections, and continue to finalize 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.”