The Boeing CST-100 Starliner has received encouraging news regarding its eventual return to Earth. Earth-based testing of the spacecraft’s thrusters, which have left it stranded in orbit since early June, has recently concluded. Boeing and NASA had been waiting for these tests to be completed before they could begin planning the vessel’s journey home.
A recent update indicated that the ground tests of the Starliner’s Reaction Control System (RCS) thruster at the White Sands Test Facility in New Mexico are finished, and teams are now focusing on reviewing the collected data. The primary goal of the testing was to examine thruster performance issues that led to some thrusters being unselected during flight, to understand the implications of potentially returning these thrusters to operational status.
The term “unselected” refers to certain thrusters that ceased functioning. Prior to and during the Starliner launch, there were leaks in the helium tanks that control the thrusters, which caused several delays. Officials noted last month that, despite the craft having 70 hours’ worth of helium—far more than the seven hours required—they are not yet ready to return the spacecraft.
In their latest communication, NASA and Boeing mentioned that a return flight could be scheduled for the end of October, but they now describe the timeline as less defined. “Boeing and NASA engineers will proceed with thruster disassembly and inspections, and will move forward with finalizing the 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,” the statement said.