Explorer 1 Instruments

This photograph shows the scientific instruments mounted inside Explorer 1 alongside its outer case. The skin of the instrument section was bare stainless steel with stripes of a white thermal material, creating a pattern of "dark" and "light" stripes. The proportion of light and dark stripes was determined by studies of the shadow-sunlight intervals based on firing time, trajectory, orbit and inclination. The assembled section was approximately 37.25 inches long.