The Boeing CST-100 Starliner has received some encouraging news regarding its return to Earth. Recently, ground tests of the spacecraft’s thrusters were completed, which had been a source of concern as the Starliner has remained in space since early June. Boeing and NASA had been awaiting the results of these tests to start planning the vessel’s homeward journey.
Last week, an update confirmed, “Ground testing of a Starliner Reaction Control System (RCS) thruster at White Sands Test Facility in New Mexico is complete, and teams are now turning their attention to data reviews.” The main goal of the tests was to examine the thruster’s performance and assess the implications of returning some thrusters to service, which had been malfunctioning during the flight.
The term “de-selected” refers to several thrusters that ceased functioning due to leaks in the helium tanks that control their operation, causing multiple delays in the mission. Officials indicated that the Starliner is equipped with 70 hours’ worth of helium, significantly more than the seven hours required for its needs. While they stated this month that the spacecraft could be ready to return if necessary, they emphasized that they are not fully prepared for the return just yet.
Recently, NASA and Boeing mentioned that a return flight could be possible by the end of the month. However, the timeline has become less definitive. The latest update notes, “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.”