To conduct the manufacturing processes needed to develop a prominent Mars base, large amounts of thermal and electrical power are essential. The best way to provide this power during the early years of base development is by importing nuclear reactors produced on Earth. Though this seems like an unpopular and controversial way of producing energy, it is one of the few options. On Mars, hydroelectric dams and fossil fuel combustion are power source options. In the long run, the prospects of thermonuclear fusion power are excellent considering the ratio of deuterium to ordinary hydrogen is five times as high as it is on Earth; however, there's a problem - fusion reactors do not currently exist. Thus, nuclear reactors are they way to go.