The crew of the Boeing CST-100 Starliner has received encouraging news regarding their return trip to Earth. Recent ground testing of the spacecraft’s thrusters, which have left it stranded in orbit since early June, has been completed. Boeing and NASA were waiting for these tests to conclude before making plans for the spacecraft’s homecoming.
An update shared last week reported: “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 tests aimed to analyze thruster performance issues, seeking to understand the reasons behind the in-flight failures of some thrusters and the potential impact of reactivating them on the Crew Flight Test.
When officials referred to “de-selected” thrusters, they meant those that malfunctioned. Helium tanks, which control the thrusters, experienced leaks prior to and during the launch, which contributed to several delays. During a press conference last month, officials mentioned that the spacecraft contains 70 hours’ worth of helium, despite only needing seven. Earlier this month, they indicated that the Starliner could return to Earth immediately if necessary, although they also noted that they were not fully prepared for such a move.
In the latest update, NASA and Boeing have suggested that the return flight could occur at the end of this month. However, the timeline is now more uncertain: “Boeing and NASA engineers will proceed with thruster disassembly and inspections, and will continue to finalize flight rationale in support of readiness reviews for Starliner’s upcoming return to Earth, piloted by commander Butch Wilmore and pilot Suni Williams, in the weeks ahead.”