UWFDM-1104 Non-Nuclear Power Sources for Deep Space

An analysis is made of the synergism of electric propulsion and non-nuclear power for deep space applications (i.e., to the asteroid belt and beyond). In current generation systems, electric propulsion is usually considered to be impractical because of the lack of high power for deep space, and non-nuclear power is thought to be impractical partly due to its high mass. However, when taken in combination, a solar powered electric upper stage can provide ample power and propulsion capability for use in deep space. Three decades ago, the mass of solar array/battery systems was so high as to preclude their practical use in deep space applications, but this is no longer the case. The high efficiency of today’s solar cells coupled with the remarkable energy storage capability of modern secondary batteries makes this a feasible technology in the near term, as demonstrated by the impressive capabilities of the SCARLET power system as well as other arrays. This paper examines in a preliminary way the possibility of using solar electric propulsion as an upper stage to boost a payload from low earth orbit to a trajectory which would take it economically as far as the orbit of Jupiter (as a hypothetical reference point), while providing the same amount of electric power at Jupiter as could be supplied by two radioisotope thermoelectric generators (RTGs).