NASA has embarked on a challenging quest to build a powerful nuclear reactor for long-duration deep space excursions. As part of the multi-pronged Prometheus Project, engineers and scientists are now tackling plans for the nuclear-powered Jupiter Icy Moons Orbiter (JIMO). This flagship mission using electric propulsion powered by a nuclear fission reactor would showcase a slate of key technologies. It also promises to usher in a new era of solar system exploration. The amount of power available to JIMO from a nuclear reactor would be hundreds of times greater than on current interplanetary spacecraft.