The crew of the Boeing CST-100 Starliner has received positive news regarding their return journey to Earth. Testing of the spacecraft’s thrusters, which had been stranded in space since early June, has recently been completed on the ground. Boeing and NASA had been awaiting the results of these tests before making plans for the spacecraft’s homecoming.
An update late last week confirmed that the ground testing of a Starliner Reaction Control System (RCS) thruster at the White Sands Test Facility in New Mexico is finished, and teams are now focused on reviewing the data. The objective of the tests was to assess thruster degradation to better understand the reasons behind some thrusters being deselected while in flight, and to evaluate any potential effects of returning those thrusters to service on the Crew Flight Test.
The term “de-selected” refers to the thrusters that ceased functioning. Prior to and during the launch, the helium tanks that control these thrusters experienced leaks, resulting in multiple delays. During a press conference last month, officials noted that the spacecraft carries 70 hours’ worth of helium, despite needing only seven. They mentioned that although the craft could technically return home at this time, they are not entirely prepared for its return.
In their latest update, NASA and Boeing indicated that a return flight could occur by 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 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.”