The Boeing CST-100 Starliner crew has received encouraging news regarding their spacecraft’s return to Earth. Recently completed ground testing of the Starliner’s thrusters, which have left it in orbit since early June, paves the way for planning the return trip. Boeing and NASA had been awaiting the results of these tests before moving forward.
An update released last week indicated, “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 purpose of the tests was to investigate thruster degradation to understand why some thrusters failed during the flight and assess the implications of potentially reactivating them for the Crew Flight Test.
The term “de-selected” refers to thrusters that malfunctioned. Leaks were found in the helium tanks that control the thrusters before and during the launch, leading to multiple delays. Officials stated last month that the Starliner contains 70 hours’ worth of helium, significantly more than the seven hours actually required. Although they indicated the spacecraft could return immediately if necessary, they also emphasized that they are not fully prepared for that.
NASA and Boeing’s most recent update suggested a potential return flight at the end of the month, but the timeframe has become less certain. “Boeing and NASA engineers will proceed with thruster disassembly and inspections and continue finalizing flight rationale to support readiness reviews for Starliner’s planned return to Earth with commander Butch Wilmore and pilot Suni Williams in the coming weeks.”