The Boeing CST-100 Starliner crew has received promising news regarding their journey home. Earth-based testing of the spacecraft’s thrusters, which have left it in orbit since early June, has recently been completed. Boeing and NASA had been awaiting the completion of these tests to initiate plans for the ship’s return.
An update released 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 primary goal of the tests was to analyze thruster degradation, helping teams understand the reasons behind the in-flight failures of some thrusters and the potential effects of reactivating those thrusters on the upcoming Crew Flight Test.
The term “de-selected” refers to some thrusters that ceased functioning. Prior to and during the Starliner’s launch, tanks containing helium to manage the thrusters were found to be leaking, contributing to several delays. During a press conference last month, officials stated that the spacecraft has an ample supply of helium, with 70 hours available, despite only needing seven. They noted earlier this month that while the craft could return home now if necessary, they are not yet fully prepared for that eventuality.
In the latest update, NASA and Boeing indicated that a return flight might occur at the end of this month. However, the timeline has since become less specific, with plans now indicating that “Boeing and NASA engineers will commence thruster disassembly and inspections, and will work towards finalizing the flight rationale in preparation for readiness reviews for Starliner’s scheduled return to Earth with commander Butch Wilmore and pilot Suni Williams in the coming weeks.”