The crew of the Boeing CST-100 Starliner has received positive news regarding their return to Earth. Recent ground tests of the spacecraft’s thrusters, which have been in a holding pattern since early June, have concluded. Boeing and NASA had been awaiting these tests to initiate plans for the spacecraft’s homecoming.
An update from 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 focusing on data analysis.” The testing aimed to assess the degradation of thrusters to better understand the issues that caused some thrusters to be deselected during flight, and to evaluate the implications of potentially returning those thrusters to operation for the Crew Flight Test.
The term “de-selected” refers to the thrusters that stopped functioning. Prior to and during the Starliner launch, the helium tanks that manage the thrusters experienced leaks, resulting in multiple delays. Officials noted that the spacecraft carries 70 hours’ worth of helium, even though it only requires seven hours. While they announced earlier this month that the Starliner could return at any time if necessary, they indicated that preparations for that return are still ongoing.
The last update from NASA and Boeing suggested that a return flight could occur at the end of the month, but the timeline has since become less specific. It was stated, “Boeing and NASA engineers will proceed with thruster disassembly and inspections and continue finalizing flight rationale in support of readiness reviews for Starliner’s planned return to Earth with commander Butch Wilmore and pilot Suni Williams in the coming weeks.”