The Boeing CST-100 Starliner crew has received encouraging news regarding their return to Earth. Ground testing of the spacecraft’s thrusters, which have prevented the vessel from returning since early June, has just concluded. Boeing and NASA were awaiting the results of these tests before starting to plan the spacecraft’s homecoming.
An update released 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 purpose of the tests was to monitor thruster degradation to better understand why certain thrusters were inoperative during flight and the potential repercussions of reactivating those thrusters on the overall Crew Flight Test.
The term “de-selected” refers to the thrusters that failed. Prior to and during the Starliner’s launch, the helium tanks controlling the thrusters were leaking, which resulted in several postponements. During a press conference last month, officials indicated that the spacecraft contains 70 hours’ worth of helium, although it requires only seven hours for its mission. While they mentioned earlier this month that the Starliner could return immediately if necessary, they acknowledged that more preparations are needed before that can happen.
NASA and Boeing’s most recent update suggested a potential return flight at the end of this month. However, that timeframe has since become less specific, stating, “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.”