The Boeing CST-100 Starliner crew has received encouraging news regarding their return to Earth. Recent ground tests of the spacecraft’s thrusters, which have left it stranded in space since early June, have been completed. Boeing and NASA were waiting for these tests to finish before planning the spacecraft’s re-entry.
An update shared late 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 reviewing the data.” The testing aimed to evaluate thruster performance and understand issues that led to some thrusters being deactivated during flight.
The term “de-selected” refers to the thrusters that malfunctioned during the mission. Prior to and during the launch, the tanks containing helium for the thrusters experienced leaks, causing several delays. Officials mentioned last month that the spacecraft has a substantial supply of helium—enough for 70 hours of operation, although it only requires seven. While they previously stated that the Starliner could return to Earth immediately if necessary, they also clarified that they are not yet fully prepared for its return.
According to the latest update, NASA and Boeing hinted that a return flight could occur by the end of this month; however, the timeline has since become less definite. The statement noted, “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.”