Just a mere 29 years ago, after President George H. W. Bush proposed a manned mission to Mars by 2019 (the 50th anniversary of the Apollo Moon Landing), NASA conducted a study to project a cost estimate. Ninety days later, they came back with a package consisting of ideas from every NASA facility in the country. This scenario required six launches to assemble a spacecraft in Earth orbit and would cost the taxpayers around half a trillion dollars. Congress put a kybosh to that idea on the spot.
Around that same time, Dr. Robert Zubrin and others at Martin Marietta came up with a plan they called Mars Direct, which would utilize some of the natural resources found on Mars. The theory was that if you don’t have to take the fuel along with you for the return trip, your spacecraft doesn’t have to be the size of the Battlestar Gallactica.
By reducing the size of the craft and utilizing a few other specialized modifications, the total cost was $50 billion, one-tenth of the NASA sum. NASA was even impressed with the ideas that the team had devised, but chose to add one more element to the mission scenario (an Earth Return Vehicle parked in Mars Orbit) as well as two additional crewmembers. NASA then called their mission profile Mars Semi-Direct.
As outlined in Phase One of the mission, an unmanned and unpressurized workshop was blasted to Mars in 2016, by a SpaceX Falcon Heavy (heavy-lift launch vehicle). Onboard was a fuel processing plant stocked with a few tons of liquid hydrogen, together with foodstuff for the flight that would follow. Along with these was an unpressurized lightweight truck carrying a One Mega Watt Electric Thermonuclear Generator mounted on a winch in the bed. Once on Mars, the truck was off-loaded and driven (remotely from Earth) onto the surface. The truck spooled out a few hundred meters of power cable as it rolled, then dropped the generator into a small crater (which provided shielding) before it was fired up. That generator is now providing the power needed to run the fuel processor.