The Boeing CST-100 Starliner crew has received positive news regarding their eventual return to Earth. Ground testing of the spacecraft’s thrusters, which have kept it in orbit since early June, has recently been completed. Boeing and NASA were awaiting these results to start organizing the spacecraft’s return journey.
An update provided late 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 focused on reviewing the data.” The goal of the test was to assess thruster degradation to better understand the in-flight de-selection of some thrusters and evaluate the potential impact of reactivating these thrusters on the upcoming Crew Flight Test.
The term “de-selected” refers to thrusters that ceased functioning. There were issues with the helium tanks controlling the thrusters, which experienced leaks both prior to and during the Starliner launch, resulting in several delays. Officials mentioned at a recent press conference that the spacecraft has 70 hours of helium onboard, although it only requires seven for its operations. While they indicated earlier this month that the Starliner could return to Earth if necessary, they also noted that it wasn’t currently prepared to do so.
The most recent update from NASA and Boeing suggested that a return flight could occur at the end of this month. However, the timeline has become less specific. They stated, “Boeing and NASA engineers will proceed with thruster disassembly and inspections and continue finalizing the flight rationale necessary to support readiness reviews for Starliner’s planned return to Earth with commander Butch Wilmore and pilot Suni Williams in the upcoming weeks.”