A new type of nuclear reactor could make it possible for us to travel to Mars in as little as two weeks.
Yigal Ronen, professor of nuclear engineering at Ben-Gurion University in Israel, believes that a little-known isotope called americium-242m (Am-242m) could power future robotic or human spacecraft more efficiently than chemical or nuclear propulsion sources.
Am-242m can sustain nuclear fission even when it is formed into thin sheets less than a micron (millionth of a meter) thick. The fission it produces makes it possible to heat materials such as hydrogen, which can be used as a propellant. The thinness of the sheets would make it easy to take along plenty of fuel for a round trip.