The Boeing CST-100 Starliner crew received encouraging news regarding their return to Earth. Testing of the spacecraft’s thrusters, which have kept it in orbit since early June, has successfully concluded. Boeing and NASA had been awaiting the completion of these tests to start planning for the spacecraft’s homeward journey.
An update last week noted, “Ground testing of a Starliner Reaction Control System (RCS) thruster at White Sands Test Facility in New Mexico is complete, and teams are now focused on reviewing the data.” The objective of the tests was to assess thruster performance and to understand the reasons behind the in-flight failure of some thrusters, as well as the potential implications of reactivating them for the upcoming Crew Flight Test.
The term “de-selected” refers to some thrusters ceasing operation. Issues with helium tanks, used to control the thrusters, caused leaks before and during the Starliner’s launch, resulting in several delays. Officials indicated that while the spacecraft has 70 hours of helium onboard, it only requires seven for its return. Although they mentioned earlier this month that the Starliner could come back at any moment if necessary, readiness for the return is still in progress.
In their most recent statement, NASA and Boeing suggested that a return flight could occur by the end of the month. However, the timeline has become less specific: “Boeing and NASA engineers will proceed with thruster disassembly and inspections, and continue advancing flight rationale to support readiness reviews for Starliner’s planned return to Earth with commander Butch Wilmore and pilot Suni Williams in the upcoming weeks.”