<div class="section abstract"><div class="htmlview paragraph">THE NUCLEAR turboelectric ion propulsion system operates as follows: <ol class="list nostyle"> <li class="list-item"> <span class="li-label">1.</span> <div class="htmlview paragraph">A nuclear reactor supplies thermal energy to a vapor boiler.</div></li> <li class="list-item"> <span class="li-label">2.</span> <div class="htmlview paragraph">The vapor drives a turbine, which operates an electric generator.</div></li> <li class="list-item"> <span class="li-label">3.</span> <div class="htmlview paragraph">The electric power is used to ionize and accelerate the propellant — a liquid alkali metal — which produces the thrust.</div></li></ol></div><div class="htmlview paragraph">Electric propulsion systems can be used in a wide variety of space missions, including satellite sustainers, lunar cargo transport, and interplanetary missions.<span class="xref">*</span></div></div>