In 1954, the USAF issued a weapons system requirement for a nuclear-powered bomber, designated WS-125. In 1956, GE teamed up with Convair (X211 program) and Pratt & Whitney with Lockheed in competitive engine/airframe development to address the requirement. In 1956, the USAF decided that the proposed WS-125 bomber was unfeasible as an operational strategic aircraft. Finally, after spending more than 1 billion dollars, the project was cancelled on March 28, 1961.