Mariner 1 was the first spacecraft of the American Mariner program, designed for a planetary flyby of Venus. It cost $18.5 million in 1962. It was launched aboard an Atlas-Agena rocket on July 22, 1962. Shortly after takeoff the rocket responded improperly to commands from the guidance systems on the ground, setting the stage for an apparent software-related guidance system failure. With the craft effectively uncontrolled, a range safety officer ordered its destructive abort 294.5 seconds after launch. According to NASA's current account for the public: