The Boeing CST-100 Starliner crew has received encouraging news regarding their potential return to Earth. Recent ground tests of the spacecraft’s thrusters, which have left it in orbit since early June, have been successfully completed. Boeing and NASA had been awaiting these tests before proceeding with plans for the spacecraft’s homeward journey.
An update released late last week indicated, “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 purpose of the tests was to assess the degradation of the thrusters, helping engineers understand why some thrusters were not operational during the flight and the potential implications of reactivating them for the Crew Flight Test.
The term “de-selected” refers to the thrusters that malfunctioned. Prior to and during the Starliner launch, helium tanks controlling the thrusters experienced leaks, resulting in several delays. Although NASA officials reported last month that the spacecraft has 70 hours’ worth of helium despite requiring only seven, they indicated that while the craft could return to Earth if necessary, they are not fully prepared for that scenario yet.
In their latest update, NASA and Boeing mentioned that a return flight could occur by the end of this month. However, this timeline is now less certain: “Boeing and NASA engineers will move forward with thruster disassembly and inspections, and finalize the flight rationale to support readiness reviews for Starliner’s standard return to Earth with Commander Butch Wilmore and Pilot Suni Williams in the coming weeks.”