The J58 is a turbojet engine developed by Pratt & Whitney for use in the Lockheed SR-71 Blackbird, a reconnaissance aircraft. It is known for its ability to operate at high speeds and altitudes, providing the necessary thrust for the SR-71 to fly at over three times the speed of sound. This engine features a unique design that includes variable geometry inlets, allowing it to efficiently manage airflow at different speeds. The J58 can produce up to 32,500 pounds of thrust, making it one of the most powerful engines of its time, contributing to the SR-71's unmatched performance in the skies.