The Boeing CST-100 Starliner team has received encouraging news regarding the spacecraft’s eventual return to Earth. Ground tests of the spacecraft’s thrusters, which have kept it in space since early June, have recently been completed. Both Boeing and NASA had been awaiting the results of these tests before planning for the spacecraft’s journey back.
An update shared last week stated, “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 aim of the testing was to identify thruster degradation and understand why some thrusters were inoperable during flight, as well as any potential consequences of reinstating those thrusters.
The term “de-selected” refers to thrusters that ceased functioning. Prior to and during the launch, helium tanks controlling the thrusters experienced leaks, resulting in several delays. Officials indicated last month that the Starliner has 70 hours’ worth of helium usage available while it only requires seven. Earlier in the month, they mentioned that the spacecraft could return immediately if necessary, but emphasized that they are not fully prepared for that scenario yet.
The latest communication from NASA and Boeing suggested that a return flight could potentially occur by the end of this month, but the timeframe has since become less specific. “Boeing and NASA engineers will proceed with thruster disassembly and inspections and continue 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 upcoming weeks.”