The crew of the Boeing CST-100 Starliner has received promising news regarding their return to Earth. Testing of the spacecraft’s thrusters, which have kept it in orbit since early June, has recently been completed. Boeing and NASA had been awaiting the completion of these tests to initiate planning for the spacecraft’s homeward journey.
An update issued late last week confirmed, “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 tests aimed to analyze thruster degradation, which will help in understanding the issues that led to the deactivation of some thrusters during flight, as well as any potential effects of reactivating them on the upcoming Crew Flight Test.
The term “de-selected” refers to some thrusters that ceased functioning. The helium tanks that regulate the thrusters experienced leaks prior to and during the Starliner launch, resulting in several delays. During a press conference last month, officials noted that the spacecraft carries 70 hours’ worth of helium, significantly more than the seven hours required for its operations. While they mentioned earlier this month that the spacecraft could return immediately if necessary, they indicated that they are not fully prepared for that step just yet.
In the latest update, NASA and Boeing noted that a return flight might be scheduled for the end of this month. However, the timeline has now become less definitive: “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 upcoming weeks.”