The two Transit program objectives were (1) to develop and demonstrate equipment to provide a reliable means of fixing the position of surface craft, submarines, and aircraft--anywhere and in any weather--more precisely, and (2) to provide more accurate maritime and aerial navigation in any weather than currently available. The Transit 2A spacecraft had as its instrument complement the following: cosmic-noise radiometer, transmitters, infrared scanner to measure satellite rotation before despin was initiated, and temperature sensors. The power supply was a nickel-cadmium battery, recharged by solar cells. The transmitters operated at the following frequencies: 54, 162, 216, and 324 MHz.