The Boeing CST-100 Starliner crew received encouraging news regarding their return to Earth. Recent ground testing completed on the spacecraft’s thrusters, which have remained in space since early June, marks a significant step forward. Boeing and NASA had awaited the results of these tests before planning for the vessel’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 concentrating on data reviews.” The objective of these tests was to analyze thruster degradation to understand why certain thrusters were rendered inoperative during flight and to assess the implications of potentially returning those thrusters to active service.
The term “de-selected” refers to thrusters that ceased functioning. Prior to and during the Starliner launch, the helium tanks that regulate the thrusters experienced leaks, which resulted in several delays. During a press conference last month, officials noted that while the spacecraft has 70 hours’ worth of helium onboard, it only requires seven hours for its current mission. Although they indicated earlier this month that the craft could return immediately if necessary, they also expressed that they are not fully prepared for that eventuality yet.
In the last update, NASA and Boeing projected a potential return flight for the end of this month. However, that timeline has become less definitive: “Boeing and NASA engineers will proceed with thruster disassembly and inspections and finalize flight rationale in support of readiness reviews for Starliner’s scheduled return to Earth with commander Butch Wilmore and pilot Suni Williams in the coming weeks.”