The Boeing CST-100 Starliner crew has received 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 completed. Both Boeing and NASA were waiting for these tests to finish before planning for the spacecraft’s journey home.
According to an update released late last week, the testing of a Starliner Reaction Control System (RCS) thruster at the White Sands Test Facility in New Mexico has concluded, with teams now reviewing the data. The main goal of the tests was to identify any degradation in the thrusters and to understand the reasons behind the in-flight de-selection of some thrusters, as well as the potential impact of returning them to service.
The term “de-selected” refers to thrusters that malfunctioned. Prior to and during the Starliner’s launch, helium tanks that control the thrusters were found to be leaking, resulting in several delays. During a press conference last month, officials mentioned that the spacecraft has 70 hours of helium onboard, while it only requires seven for its operations. Although they affirmed earlier this month that the Starliner could return immediately if necessary, they indicated that they are not fully prepared for that scenario.
In the most recent update, NASA and Boeing indicated that a return flight could occur by the end of this month. However, the timeline has become less specific: “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.”