Human exploration of Mars could be feasible in 10 to 15 years, using a revolutionary rocket powered by a nuclear reactor, two NASA experts say. Stanley K. Borowski and Leonard Dudzinski of NASA’s Glenn Research Center, Cleveland, explained the vision Wednesday at a national conference on space propulsion held in Salt Lake City. Among the huge rocket engines and displays, a stand-out information kiosk was that manned by Borowski and Leonard. Using models, posters and video, they detailed plans for a nuclear rocket that could land astronauts on Mars.