The Boeing CST-100 Starliner crew recently received encouraging news regarding their return to Earth. Ground tests on the spacecraft’s thrusters, which have left it stranded in space since early June, have been successfully completed. Boeing and NASA had been awaiting these tests to begin planning the spacecraft’s journey back home.
An update last week reported that “ground testing of a Starliner Reaction Control System (RCS) thruster at White Sands Test Facility in New Mexico is complete, and teams are now focusing on reviewing the data.” The primary goal of these tests was to examine thruster performance to understand why certain thrusters failed during flight and to evaluate the potential effects of reinstating them on the remainder of the Crew Flight Test.
When officials refer to “de-selected” thrusters, they are indicating that some became inoperative. Problems with the helium tanks that control the thrusters led to leaks both before and during the launch, causing several delays. During a press conference last month, officials stated the spacecraft currently holds enough helium for 70 hours, even though it only requires seven hours for its mission. They noted that while the craft could technically return to Earth now if necessary, the team is not quite ready to execute the return.
The latest updates from NASA and Boeing mentioned that a return flight could potentially happen at the end of this month. However, the timeline has now shifted to a more ambiguous forecast, stating that “Boeing and NASA engineers will proceed with thruster disassembly and inspections, and will continue 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.”