The Boeing CST-100 Starliner team has received encouraging news regarding the spacecraft’s return to Earth. Recent tests on the spacecraft’s thrusters, which have left it in orbit since early June, have been successfully completed. Both Boeing and NASA were awaiting the completion of these tests to start planning for the vessel’s homecoming.
An update shared late last week confirmed, “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.” The purpose of the tests was to investigate thruster degradation, which would provide insights into why certain thrusters were rendered inoperative during the flight and assess the implications of potentially reactivating those thrusters for the Crew Flight Test.
The term “de-selected” refers to the thrusters that failed to operate. Issues with helium tanks, responsible for controlling the thrusters, were identified both before and during the Starliner’s launch, resulting in several delays. Officials mentioned last month that while the spacecraft has 70 hours of helium on board—far exceeding the seven hours it actually requires—they are not yet prepared for an immediate return, despite earlier statements indicating it could come home if necessary.
NASA and Boeing’s most recent update suggested that a return flight could happen towards the end of this month. However, this timeline has become more uncertain, with engineers from both organizations set to take apart and inspect the thrusters. They will also work on finalizing the flight rationale to support readiness reviews for Starliner’s intended return to Earth with commander Butch Wilmore and pilot Suni Williams in the upcoming weeks.