The crew of the Boeing CST-100 Starliner has received promising news regarding its return to Earth. Recent ground tests of the spacecraft’s thrusters, which have left it in space since early June, have been completed. Boeing and NASA had awaited these tests before making plans for the vehicle’s homeward journey.
An update indicated that the ground testing of a Starliner Reaction Control System (RCS) thruster at the White Sands Test Facility in New Mexico has concluded, and teams are now focusing on analyzing the data. The objective of the tests was to assess thruster degradation to better understand why some thrusters were not functioning during flight, and how returning those thrusters to service might affect the overall Crew Flight Test.
The term “de-selected” refers to thrusters that ceased to operate. Prior to and during the Starliner launch, the helium tanks controlling the thrusters experienced leaks, resulting in several delays. Officials mentioned last month that the spacecraft retains 70 hours’ worth of helium onboard, despite only needing seven. While they noted that the craft could return to Earth immediately if necessary, they also stated that they are not yet fully prepared for that to happen.
In the latest update, NASA and Boeing suggested that a return flight could occur by the end of this month. However, the timeline is now more ambiguous: “Boeing and NASA engineers will proceed with thruster disassembly and inspections, and finalize 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.”