The Boeing CST-100 Starliner crew has received encouraging news regarding its eventual return to Earth. Recently, ground testing of the spacecraft’s thrusters, which have left it in orbit since early June, was completed. Boeing and NASA awaited the outcome of these tests before starting preparations for the vehicle’s homecoming.
An update from last week noted, “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 reviews.” The goal of the tests was to identify thruster degradation and gain insights into why certain thrusters failed during flight, as well as to assess potential impacts of reactivating those thrusters on the upcoming Crew Flight Test.
Some thrusters had been identified as “de-selected,” indicating that they had ceased functioning. Issues arose with the helium tanks that control the thrusters, leading to leaks prior to and during the Starliner’s launch, resulting in several delays. Officials previously reported that the spacecraft carries 70 hours’ worth of helium, despite only needing seven hours. While they stated earlier this month that the Starliner could return if necessary, they emphasized they are not yet fully prepared for that scenario.
In the latest update, NASA and Boeing indicated that a return flight could occur at the end of this month. However, the timeline has since become less definitive: “Boeing and NASA engineers will proceed with thruster disassembly and inspections and advance toward finalizing flight rationale in support of readiness reviews for Starliner’s planned return to Earth with commander Butch Wilmore and pilot Suni Williams in the coming weeks.”