The team behind the Boeing CST-100 Starliner has received encouraging news regarding the spacecraft’s return to Earth. Earth-based testing of the Starliner’s thrusters, which have kept the craft in space since early June, has recently concluded. Boeing and NASA were waiting for these tests to finalize plans for the spacecraft’s journey back home.
An update released last week confirmed, “Ground testing of a Starliner Reaction Control System (RCS) thruster at White Sands Test Facility in New Mexico is complete, and teams are now reviewing the data.” The primary goal of the test was to analyze thruster performance issues that led to some thrusters being disabled during flight, and to assess the potential impacts of reactivating them on the upcoming Crew Flight Test.
The term “de-selected” refers to the thrusters that failed to function during the mission. There were leaks in the helium tanks that control the thrusters prior to and during the Starliner launch, which resulted in several delays. Officials noted last month that the spacecraft has 70 hours of helium on board, much more than the seven hours required. Although they previously mentioned that the Starliner could return to Earth immediately if necessary, they indicated that they are not fully prepared for that to happen yet.
As of the latest communication, NASA and Boeing suggested that the return flight could potentially occur at 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 will continue finalizing the flight rationale to support readiness reviews for Starliner’s nominal return to Earth with commander Butch Wilmore and pilot Suni Williams in the coming weeks.”