The Boeing CST-100 Starliner crew received encouraging news regarding their return home as Earth-based testing of the spacecraft’s thrusters has recently concluded. The thrusters had kept the spacecraft in orbit since early June. NASA and Boeing were awaiting the completion of these tests to start organizing the vessel’s journey back to Earth.
A statement released last week noted, “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 focusing on data reviews. The aim of this testing was to analyze thruster degradation to better understand the failure of certain thrusters during flight and assess any potential impacts of restoring those thrusters to service for the upcoming Crew Flight Test.”
Some thrusters had been “de-selected,” or rendered inoperative, as helium tanks controlling them experienced leaks both prior to and during the Starliner’s launch, causing multiple delays. During a press conference last month, officials mentioned the spacecraft holds 70 hours’ worth of helium, significantly more than the seven hours required for its operations. Although they indicated that the Starliner could return immediately if necessary, they also expressed that they were not yet prepared for that eventuality.
In their latest communication, NASA and Boeing suggested that a return flight might occur at the end of this month. However, the timeline has become less specific: “Boeing and NASA engineers will proceed with thruster disassembly and inspections, and advance towards finalizing flight rationale to support readiness reviews for Starliner’s planned return to Earth with commander Butch Wilmore and pilot Suni Williams in the upcoming weeks.”