Great for beginners (and priced accordingly), this option features a wide, 60 millimeter aperture that will make stars and constellations appear bright and clear. And they contrast with traditional chemical rockets, where chemical propellants like liquid oxygen are used to make something more like a supersized fossil fuel combustion engine. These designs use the astonishing heat generated by a nuclear reaction to push a rocket at speeds approaching the Star Trek realm compared to what we use today. While weapons are thermal, other applications have lingered in the experimental stage and then been discarded, but they’ve still been studied off and on for decades. Thermal nuclear for propulsion is an old idea. “The problem is to produce a nuclear reactor that is light enough and safe enough for use outside the Earth's atmosphere-especially if the spacecraft is carrying a crew,” New Atlas explains. By using ceramic microcapsules of high assay low enriched uranium (HALEU) fuel, USNC's thermal nuclear engine could cut the trip in half even from optimistic estimates.

Ultra Safe Nuclear Corporation (USNC) has designed a new thermal nuclear engine it says could carry astronauts to Mars in just three months-and back to Earth in the same amount of time. This company's ceramic-coated pellet fuel is low enriched, safer, and more stable.Elon Musk has referred to ideas like this as a way to keep astronauts safe from cosmic radiation.Thermal nuclear propulsion could cut travel time to Mars down to just three months.

Nuclear time to mars