The crew of the Boeing CST-100 Starliner has received positive news regarding their return to Earth. Earthbound testing of the spacecraft’s thrusters, which have left it stranded in orbit since early June, has recently concluded. Boeing and NASA were awaiting the completion of these tests to start planning the spacecraft’s homecoming.
An update released late last week stated, “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 focused on reviewing the data.” The main goal of the tests was to assess thruster degradation, which would help explain why some thrusters had malfunctioned during the flight and what effects reactivating those thrusters might have on the upcoming Crew Flight Test.
The term “de-selected” indicates that certain thrusters ceased functioning. The helium tanks, which control the thrusters, were reported to have leaks prior to and during the Starliner launch, resulting in several delays. During a press conference last month, officials noted that the spacecraft has 70 hours of helium available, although it only requires seven hours for its operations. They mentioned earlier this month that the craft could return immediately if necessary, but they are not fully prepared for that eventuality yet.
In their latest statement, NASA and Boeing indicated that a return flight might occur at the end of the month. However, the timeline has since become less specific: “Boeing and NASA engineers will proceed with thruster disassembly and inspections, and continue to finalize flight rationale to support readiness reviews for Starliner’s nominal return to Earth with commander Butch Wilmore and pilot Suni Williams in the coming weeks.”