The crew of the Boeing CST-100 Starliner has received positive indications regarding its return to Earth. Recent ground tests of the spacecraft’s thrusters were successfully completed, marking a significant step after the Starliner has remained in orbit since early June. Boeing and NASA had been awaiting the results of these tests to plan for the spacecraft’s re-entry.
According to an update released late last week, “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 tests aimed to assess thruster performance and understand the reasons behind the in-flight deactivation of some thrusters, as well as the potential implications of reactivating them.
The term “de-selected” refers to the thrusters that faced operational failures. Prior to and during the Starliner launch, there were issues with helium tanks that control the thrusters, which resulted in several delays. During a press conference last month, officials indicated that the spacecraft had 70 hours’ worth of helium on board, although it only requires seven for its operations. While they asserted that the craft could return to Earth immediately if necessary, they also stated that they were not fully prepared for that eventuality.
In their latest update, NASA and Boeing suggested that a return flight could occur by the end of this month. However, the timeline has since become less specific: “Boeing and NASA engineers will proceed with thruster disassembly and inspections and continue to finalize flight rationale for readiness reviews for Starliner’s expected return to Earth with commander Butch Wilmore and pilot Suni Williams in the coming weeks.”