The Boeing CST-100 Starliner team received encouraging news about the spacecraft’s return to Earth. Recent ground tests of the spacecraft’s thrusters, which have kept it in orbit since early June, have been completed. Boeing and NASA were waiting on these tests to start planning the vehicle’s return journey.
An update announced the completion of a ground test for the Starliner Reaction Control System (RCS) thrusters at the White Sands Test Facility in New Mexico, allowing teams to focus on data analysis. The purpose of the tests was to observe any degradation in the thrusters to understand why some of them were inoperative during flight and to assess the potential impacts of returning those thrusters to service for the Crew Flight Test.
The term “deselected” indicates that certain thrusters failed to function. Issues with the helium tanks that control the thrusters, including leaks before and during the Starliner launch, resulted in several delays. Officials reported last month that the spacecraft has 70 hours of helium onboard, well above the seven hours it needs. They mentioned that while the Starliner could return immediately if necessary, it is not yet ready for that.
In their most recent update, NASA and Boeing projected that a return flight might be possible by the end of this month. However, the timeline has become less definite: “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.”