In 1969, the National Air Pollution Control Administration announced a competition for a contract to design a practical passenger-car steam engine. Five firms entered. They were the consortium of Planning Research Corporation and STP Corporation, Battelle Memorial Institute, Columbus, Ohio, Continental Motors Corporation, Detroit, Vought Aeronautical Division of Ling-Temco-Vought, Dallas and Thermo Electron Corporation, Waltham, Massachusetts.[24]