The Boeing CST-100 Starliner crew received encouraging news regarding their return to Earth. Recently completed ground tests of the spacecraft’s thrusters, which have been stationed in space since early June, mark a significant step forward. Boeing and NASA had been awaiting the outcomes of these tests to start planning the spacecraft’s homeward journey.
An update from last week confirmed, “Ground testing of a Starliner Reaction Control System (RCS) thruster at White Sands Test Facility in New Mexico is complete, and teams are now turning their attention to data reviews.” The primary goal of the test was to evaluate thruster degradation to better understand why certain thrusters were nonoperational during the flight and to assess the implications of potentially reactivating them for the upcoming Crew Flight Test.
When officials refer to “de-selected” thrusters, they mean that some ceased functioning properly. Prior to and during the Starliner launch, the helium tanks controlling the thrusters experienced leaks, which resulted in several delays. A press conference last month revealed that the spacecraft has 70 hours of helium on board, although only seven hours are necessary for the mission. While officials stated earlier this month that the Starliner could return immediately if required, they indicated that they are not fully prepared for that eventuality.
In their most recent communication, NASA and Boeing mentioned that a return flight might happen by the end of this month. However, the timeline has since 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.”