The Pioneer 11 (or Pioneer Saturn) spacecraft will fly through and by Saturn's famous rings on or about September 1. This will be the climax of a 6-year trip at an average velocity of 50,000 mph for nearly 109 miles. Pioneer 11 has instruments to measure various quantities similar to those of Voyager during the March and July Jupiter flybys, and thus it will provide an interesting comparison of the properties of the two gaseous planets. Saturn's gravitational, magnetic, and radiation fields will be studied, as will the temperature and composition of its outer atmosphere. The mysterious green, yellow, and orange colors of Saturn's surface and rings may be explained. The particles of the rings and clouds that surround Saturn could be of sufficient size to damage the spacecraft.