Physicists' Early Dreams of Nuclear Powered Spaceflight

Considering how much space junk is in orbit, the need to maintain and monitor cislunar space (the region between Earth and the Moon) is becoming an increasingly important issue. To do so effectively may require spacecraft that can propel for longer durations than currently available, and nuclear reactors may offer a solution. Recent news of progress utilizing nuclear technology to power extended spaceflight -- from the Demonstration Rocket for Agile Cislunar Operations (DRACO) program, SpaceNuke...