The Boeing CST-100 Starliner crew has received encouraging news regarding their return to Earth. Testing of the spacecraft’s thrusters, which have left it stranded in space since early June, has recently concluded. Boeing and NASA had been awaiting these test results before making plans for the spacecraft’s return.
An update from last week indicated, “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 focused on data reviews.” The primary goal of the testing was to analyze thruster performance degradation, which would help the teams understand why some thrusters were rendered inoperative during flight and assess any potential impacts of bringing those thrusters back into service for the Crew Flight Test.
The term “de-selected” refers to thrusters that became non-operational. The helium tanks that control these thrusters experienced leaks both prior to and during the Starliner’s launch, resulting in several delays. During a press conference last month, officials noted that the spacecraft has 70 hours’ worth of helium on board, despite only requiring seven hours. While they mentioned that the craft could return if necessary, they also clarified that they weren’t yet prepared for that eventuality.
In their latest update, NASA and Boeing suggested that a return flight could happen by the end of the month. However, the timeline is now less specific: “Boeing and NASA engineers will proceed with thruster disassembly and inspections, and continue to finalize 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.”