The crew of the Boeing CST-100 Starliner has received optimistic news regarding their return to Earth. Ground testing of the spacecraft’s thrusters, which had left it stranded in space since early June, has recently been completed. Boeing and NASA were awaiting these tests before organizing the Starliner’s homeward journey.
An update released last week noted, “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 the data review.” The goal of the test was to assess thruster degradation to understand the reasons behind the in-flight issues that led to some thrusters being taken offline and to evaluate the potential effects of restoring them to service ahead of the Crew Flight Test.
The term “de-selected” refers to those thrusters that malfunctioned. Previously, helium tanks responsible for controlling the thrusters experienced leaks both before and during the Starliner’s launch, resulting in several delays. During a press conference last month, officials indicated that the spacecraft has 70 hours of helium onboard, although only seven hours are required for operation. They mentioned that while the craft could technically return immediately if necessary, it is not yet fully prepared for that step.
The most recent update from NASA and Boeing suggested a potential return flight by the end of this month. However, this timeline has become less specific: “Boeing and NASA engineers will proceed with thruster disassembly and inspections and will work on finalizing flight rationale to support readiness reviews for the Starliner’s planned return to Earth with commander Butch Wilmore and pilot Suni Williams in the coming weeks.”