Pioneer 11

Pioneer 11 (also known as Pioneer G) is a 259-kilogram (571 lb) robotic space probe launched by NASA to study the asteroid belt, the environment around Jupiter and Saturn, solar wind, and cosmic rays. It was the first probe to encounter Saturn and the second to fly through the asteroid belt and by Jupiter. Thereafter, Pioneer 11 became the second of five artificial objects to achieve the escape velocity that will allow them to leave the Solar System.