Boeing’s CST-100 Starliner spacecraft is showing promising signs regarding its return to Earth. Recently completed ground testing of the spacecraft’s thrusters, which have inhibited its descent since early June, has paved the way for Boeing and NASA to begin planning the return mission.
Notably, the ground testing of a Starliner Reaction Control System (RCS) thruster at the White Sands Test Facility in New Mexico has concluded, according to an update released last week. This phase aimed to investigate thruster degradation to understand why certain thrusters were rendered inoperative during the flight and assess the implications of restoring them to service for the upcoming Crew Flight Test.
The term “de-selected” refers to thrusters that ceased functioning, a situation attributed to leaks in the helium tanks that manage the thrusters prior to and during the launch of Starliner. At a press conference last month, officials indicated that the spacecraft has a reserve of 70 hours’ worth of helium on board, despite only requiring seven hours. While they noted that the Starliner could return at any time if necessary, they also emphasized that preparations are not fully complete.
In their latest update, NASA and Boeing stated that a potential return flight could occur by the end of this month. However, the timeline has become somewhat less specific: “Boeing and NASA engineers will conduct thruster disassembly and inspections, and advance with finalizing flight rationale to support readiness reviews for Starliner’s scheduled return to Earth with commander Butch Wilmore and pilot Suni Williams in the upcoming weeks.”