The crew of the Boeing CST-100 Starliner has received encouraging news regarding its return to Earth. Recently, ground testing of the spacecraft’s thrusters was completed, marking a significant step toward planning the vehicle’s homecoming after it has been in space since early June. Boeing and NASA were waiting for these tests to conclude before formulating a strategy for the Starliner’s return journey.
An update from last week confirmed the successful completion of tests on the Starliner’s Reaction Control System (RCS) thrusters at the White Sands Test Facility in New Mexico. The testing aimed to observe any degradation in the thrusters, which had previously been de-selected during flight due to performance issues. Teams are currently focused on reviewing the test data to understand the impact of returning those thrusters to operational status and how it affects the overall Crew Flight Test.
The term “de-selected” refers to thrusters that ceased functioning. Prior to and during the Starliner’s launch, there were leaks in the helium tanks responsible for operating the thrusters, which contributed to delays. Despite having 70 hours’ worth of helium onboard—far more than the seven hours required—officials indicated that while the spacecraft could return at any moment if necessary, they are not fully prepared for that contingency yet.
In previous updates, NASA and Boeing suggested that a return flight could happen by the end of this month. However, the timeline has become less certain. Boeing and NASA engineers are now focused on disassembling and inspecting the thrusters and finalizing preparations for Starliner’s planned return to Earth, which will involve commander Butch Wilmore and pilot Suni Williams in the upcoming weeks.