Power supplies for space vehicles

The requirements for electrical power in space vehicles over the next five years are reviewed and estimated figures given with particular reference to power/weight ratio. Vehicle life duration and its effect on choice of supply are discussed. Problems encountered in space vehicles due to environmental conditions, e.g. temperature, radiation, zero gravity, etc., are then pointed out. The available generation methods are: thermo electric generators; thermionic converters; the fuel cell; solar energy nuclear sources; magneto-hydrodynamic methods.