the crres spacecraft had the shape of an octagonal prism with solar arrays on the top side. the prism is 1 m high and 3 m between opposite faces. four of the eight compartments were for the chemical canisters and the other four housed the spacerad and other experiments. the spacecraft body was spun at 2.2 rpm about a spin axis in the ecliptic plane and kept pointed about 12 degrees ahead of the sun's apparent motion in celestial coordinates. pre-launch and in-flight operations were supported by the space test and transportation program office of the u.s. air force space division.