The Boeing CST-100 Starliner crew received promising news regarding their return to Earth. Recently, ground testing of the spacecraft’s thrusters, which have left it orbiting since early June, was successfully completed. Both Boeing and NASA had been awaiting the conclusion of these tests to start formulating plans for the spacecraft’s journey home.
An update from last week indicated that the ground testing of a Starliner Reaction Control System (RCS) thruster at the White Sands Test Facility in New Mexico is finished, and attention is now shifting to reviewing the data collected. The objective of the test was to investigate thruster degradation to better understand why some thrusters were inactive during flight and evaluate the implications of reactivating them for the remainder of the Crew Flight Test.
The term “de-selected” refers to the thrusters that stopped functioning. Issues arose before and during the Starliner launch due to leaks in the helium tanks that control the thrusters, causing several delays. Officials reported last month that the spacecraft has 70 hours of helium available, although it only requires seven for its operations. While they indicated earlier this month that the Starliner could return immediately if necessary, they also noted that it is not yet fully prepared for that eventuality.
The most recent update from NASA and Boeing mentioned that a return flight was possible by the end of the month. However, the timeline has since become less definitive: “Boeing and NASA engineers will proceed with thruster disassembly and inspections, and move forward with finalizing 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.”