The crew of the Boeing CST-100 Starliner has received some encouraging news regarding their return to Earth. Recent ground tests of the spacecraft’s thrusters, which have left it in orbit since early June, have been completed. Boeing and NASA had been awaiting the results of these tests before planning the Starliner’s homecoming.
An update shared 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 turning their attention to data reviews.” The purpose of the tests was to examine thruster degradation to better understand the reasons behind the in-flight failure of some thrusters and assess the potential effects of restoring these thrusters to operation.
The term “de-selected” refers to the thrusters that ceased functioning. Helium tanks, responsible for controlling the thrusters, experienced leaks prior to and during the Starliner launch, resulting in several delays. During a press conference last month, officials noted the spacecraft has 70 hours of helium onboard, although it only requires seven hours. While they mentioned earlier this month that the craft could return immediately if necessary, they indicated that they are not fully prepared for its reentry yet.
In their most recent update, NASA and Boeing noted that a return flight could occur at the end of this month. However, the timeline has become less defined: “Boeing and NASA engineers will proceed with thruster disassembly and inspections and continue finalizing flight rationale to support readiness reviews for Starliner’s nominal return to Earth, featuring commander Butch Wilmore and pilot Suni Williams, in the coming weeks.”