The Nuclear Europa Mobile Ocean (NEMO) mission would land on the surface of Europa, and deploy a small, lightweight melt probe powered by a compact nuclear reactor to melt down through the multi-kilometer ice sheet. After reaching the sub-surface ocean, a small nuclear Autonomous Underwater Vehicle (AUV) would deploy to explore the sub-ice ocean. After exploration and sample collection, the AUV would return to the probe and melt back to the lander. The lander would have replenished its H2 propellant by electrolysis of H2O ice, and then hop to a new site on Europa to repeat the probe/AUV process. After completing the mission, the NEMO spacecraft would return to Earth with its collected samples. The NEMO melt probe and AUV utilize enriched U-235 fuel and conventional water reactor technology. The lander utilizes a compact nuclear thermal propulsion (NTP) engine based on the 710tungsten/UO2 cermet fuel and high-temperature H2 propellant. The compact nuclear reactors in both the NEMO melt probe and AUV drive a steam power cycle, generating over 10 kW(e) for use in each. Each nuclear reactor's operating lifetime is several years. With its high-mobility and long-duration mission, NEMO provides an ideal platform for life detection experiments.