The crew of the Boeing CST-100 Starliner has received encouraging news regarding its eventual return to Earth. Earth-based tests on the spacecraft’s thrusters, which have left it in orbit since early June, have recently been completed. Boeing and NASA had held off on planning for the vessel’s return until these tests were conducted.
An update issued late last week revealed, “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 focus to data reviews.” The purpose of the tests was to examine thruster degradation, enabling teams to understand better why some thrusters were disabled during flight and the potential effects of returning them to service on the overall Crew Flight Test.
The term “de-selected” refers to the thrusters that ceased functioning. Issues with the helium tanks controlling the thrusters surfaced before and during the Starliner launch, causing multiple delays. During a press conference last month, officials confirmed that despite the vessel having 70 hours of helium onboard, it only requires seven hours for operation. Although they stated earlier this month that the spacecraft could return home if necessary, they emphasized that they are not fully prepared for that outcome.
In the latest update, NASA and Boeing indicated that a return flight might occur by the end of this month. However, the timeline has since become less definitive: “Boeing and NASA engineers will carry out thruster disassembly and inspections, and will move forward with finalizing the flight rationale in preparation for readiness reviews for Starliner’s anticipated return to Earth, with commander Butch Wilmore and pilot Suni Williams in the coming weeks.”