Human mission to Mars propellant from the Martian Atmosphere. This proposal drew on concepts developed by the former "Case for Mars" conference series. Over the next decade, Zubrin developed it into a mission concept, Mars Direct, which he presented in a book, "The Case for Mars" (1996). The mission is advocated by the Mars Society, which Zubrin founded in 1998, as practical and affordable. In 1991 in Toulouse, France, the International Space University studied an international human Mars mission. They proposed a crew of 8 traveling to Mars in a nuclear-powered vessel with artificial gravity provided by rotation. On the surface, 40 tonne habitats
A Princess of Mars the planetary romance had become very popular in the emerging science fiction pulp magazines. The novel can also be classified as the closely related genre sword and planet, which consists of what are essentially sword and sorcery stories that take place on another planet. "A Princess of Mars" is widely considered to be the archetypal novel of the sword and planet genre. The novel also shares a number of elements of Westerns, such as desert settings, women taken captive, and a climactic life-or-death confrontation with the antagonist. Burroughs employs a literary device for "A Princess of Mars" to which he