The Boeing CST-100 Starliner crew has received positive news regarding their return to Earth. Testing of the spacecraft’s thrusters, which have kept it in orbit since early June, has concluded successfully. Boeing and NASA had been awaiting these tests to initiate planning for the spacecraft’s journey back home.
An update released last week stated, “Ground testing of a Starliner Reaction Control System (RCS) thruster at the White Sands Test Facility in New Mexico is complete, and teams are now turning their attention to data reviews.” The purpose of the tests was to analyze thruster performance, particularly why some thrusters were rendered inoperable during the flight, and to assess the implications of potentially reinstating those thrusters for the remainder of the Crew Flight Test.
Some thrusters were labeled as “de-selected,” indicating they had stopped functioning. Prior to and during the launch, the helium tanks responsible for controlling the thrusters experienced leaks, resulting in multiple delays. Officials noted last month that the Starliner has 70 hours’ worth of helium onboard, although only seven hours are required for its operations. They had indicated earlier this month that the spacecraft could return immediately if necessary, but they also made it clear that they are not quite prepared for that to happen.
In the most recent update, NASA and Boeing indicated that the return flight could occur by the end of this month. However, the timeline has shifted to a less specific window: “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.”