NASA continues to be interested in returning to the Lunar surface. The Lunar surface is a harsh and unforgiving environment. Perhaps most challenging is the drastic and length thermal cycle surface equipment will experience on the surface. Standard spacecraft electronics and batteries cannot survive the extremes of the Lunar thermal cycle and must be protected by a thermal control system (TCS) that often features Plutonium-238 which is an expensive, strictly controlled material that is not a viable option for lower cost or commercial missions. An alternative approach would be an extreme environment flywheel energy storage system that could supply enough power to heat the critical electronics during the Lunar night. Honeybee Robotics Spacecraft Mechanisms Corporation (Honeybee) proposes to develop an extreme environment Flywheel Energy Storage (FES) system that enables a small spacecraft (e.g., 200 kg Lunar Rover) to repeatedly survive the long, cold Lunar night. The FES system will also supply operational power during the Lunar day.