The Boeing CST-100 Starliner crew has received encouraging news regarding their upcoming return to Earth. Earth-based testing of the spacecraft’s thrusters, which have left it stranded in orbit since early June, has recently been completed. Boeing and NASA had been waiting for these tests to conclude before finalizing the plans for the spacecraft’s return journey.
In an update released last week, it was announced that the ground testing of a Starliner Reaction Control System (RCS) thruster at the White Sands Test Facility in New Mexico has been completed, and teams are now focusing on reviewing the data. The purpose of the tests was to examine thruster performance to understand why some thrusters were inoperative during flight and to assess any potential effects of reactivating them on the upcoming Crew Flight Test.
The term “de-selected” was used by officials to indicate that some thrusters had failed to operate. There had been issues with the helium tanks used to control the thrusters, which were found to be leaking both before and during the Starliner launch, causing several delays. Officials mentioned last month that the spacecraft is equipped with 70 hours of helium, even though only seven hours are needed. Although they noted earlier this month that the ship could return if necessary, they also indicated that they are not yet fully prepared for the return.
In the latest update, NASA and Boeing mentioned that a return flight might occur at the end of this month. However, the timeline is now less clear: “Boeing and NASA engineers will proceed with thruster disassembly and inspections, and move forward with finalizing flight rationale in support of readiness reviews for Starliner’s nominal return to Earth with commander Butch Wilmore and pilot Suni Williams in the coming weeks.”