NASA Administrator Jared Isaacman and other agency leaders outlined plans for a nuclear-powered mission to Mars in December 2028. The mission appears to be based on the previous attempt by the U.S. to develop an unmanned nuclear rocket, called SR-1 Freedom. The propulsion is nuclear electric. This means that the reactor heat from the 25-kilowatt reactor will be converted to electricity by a generator (called a Brayton cycle generator), which will then power xenon gas thrusters. The NERVA rocket of the 1960s was designed to use its reactor to superheat hydrogen gas, which made a powerful rocket propulsion. Xenon thrusters produce much less thrust and specific impulse.
SR-1 would take about one year to reach Mars.
