SNAP-15A Radioisotope Thermoelectric Generator

In the output power range below one electrical watt, the combination of an isotope heat source with a metallic thermoelectric converter yields characteristics that are superior to systems employing other kinds of energy sources or conversion methods. When the output power is to be delivered at a high impedance, the metallic thermocouple shows a substantial advantage over the semiconductor thermocouples. The isotope-metal thermocouple system can be designed to yield other important power source characteristics such as the ability to withstand severe mechanical vibration and shock and to produce constant output power over a very wide range of temperature ambients. The design for the present (SNAP-15A) device allows for an ambient range of from -65° to + 165° F, but a much wider range can be accommodated. Transient response to ambient temperature change can be tailored to specific requirements for uniform power output. Finally, the device can operate under water, in air, or in vacuum. The device characteristics support a wide range of potential applications. Following are some of the applications under consideration: 1. Provide a steady reference voltage for long life applications. 2. Supply a network of radio beacons for the lunar landing area. 3. Power transmitters for remote weather and detection data. 4. Provide fail-safe ultrareliable long-life power in space satellites. 5. Power miniaturized communication sets. The degree to which the new device is competitive with other power sources for such applications depends on the detailed requirements.