The Boeing CST-100 Starliner crew has received some encouraging news regarding their return to Earth. Recent ground testing of the spacecraft’s thrusters, which have left it in orbit since early June, has been successfully completed. Boeing and NASA were waiting for these tests to conclude before planning the spacecraft’s homeward journey.
An update released last week stated, “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 data analysis.” The primary objective of the test was to assess thruster performance and understand the reasons behind the deactivation of some thrusters during the flight, as well as the potential implications of reintegrating these thrusters for the upcoming Crew Flight Test.
The term “de-selected” refers to thrusters that ceased functioning. There were issues with the helium tanks that control these thrusters, which leaked before and during the launch, resulting in multiple delays. Officials mentioned last month that the spacecraft contains 70 hours’ worth of helium onboard, even though it only requires seven hours. While they indicated earlier this month that the Starliner could technically return at any moment if necessary, they have clarified that preparations for the return are still ongoing.
In the latest update, NASA and Boeing suggested that a return flight could possibly occur by the end of the month. However, they have now indicated that the timeline is less certain: “Boeing and NASA engineers will move forward with the disassembly and inspection of the thrusters, and will finalize the flight rationale to support readiness reviews for Starliner’s planned return to Earth with commander Butch Wilmore and pilot Suni Williams in the upcoming weeks.”