Space missions are very costly, limited and often short-lived. The capabilities and value of a space mission depends on the energy and power available on a space craft. For many space missions it is not possible to bring an energy source that can supply the required power throughout the entire duration of the mission. Furthermore, spacecrafts often generate excess heat that is largely unused. Cooling systems on spacecrafts are designed to radiate unwanted heat into space to prevent overheating. However, unwanted heat on spacecrafts has great potential to generate electric power. The objective of this project is to integrate a novel thermophotovoltaic (TPV) device into a spacecraft propulsion system. TPV devices use a photovoltaic cell to convert radiant heat into electric power. The TPV system in this project comprises a novel optical cavity structure that concentrates radiant energy from a heat source onto a PV cell. This TPV system is made of durable and inexpensive components, has no moving parts, and does not generate vibrations which could hinder the operation of a spacecraft.