The Boeing CST-100 Starliner crew has received encouraging news regarding their return to Earth. Ground tests of the spacecraft’s thrusters, which have left it in orbit since early June, have recently concluded. Boeing and NASA had been awaiting these results to begin planning the spacecraft’s repatriation.
“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 reviews,” said an update from last week. “The objective of the test was to assess thruster degradation to better understand why some thrusters were deactivated during flight, and to evaluate any potential impacts of reintroducing those thrusters for the remainder of the Crew Flight Test.”
The term “deactivated” refers to the failure of some thrusters to function. Issues with the helium tanks controlling the thrusters, which experienced leaks both before and during the launch, caused several delays. Officials mentioned in a press conference last month that the spacecraft has 70 hours’ worth of helium on board, although it only requires seven. While they indicated earlier this month that the Starliner could return immediately if necessary, they acknowledged they are not fully prepared for that to happen just yet.
In their most recent statement, NASA and Boeing suggested that a return flight could be scheduled for the end of this month. However, the timeline has since become less specific: “Boeing and NASA engineers will conduct thruster disassembly and inspections, and will proceed with finalizing the flight rationale in support of readiness reviews for Starliner’s anticipated return to Earth with commander Butch Wilmore and pilot Suni Williams in the upcoming weeks.”