The testing leads the teams to believe that the thrusters are prone to overheating during docking. Higher temperatures may have caused propellant to vaporize, interrupting the mixing of oxidizer and fuel required for the thrusters to properly work, which then reduced the thruster pressure and resulted in the lower readings.

The thrusters will burn up in Earth’s atmosphere. They belong to the Starliner’s service module, which the Starliner will jettison before the crew module begins landing procedures. With no hardware to examine back on Earth, these tests are the last glimpse teams will get of the thrusters of the U.S.’s new human-rated spacecraft.