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
Earthling English "yrþling", in the meaning "ploughman". The sense of "inhabitant of earth" is first attested in the 1590s. Its use in science fiction dates to 1949, in "Red Planet" by Robert A. Heinlein. The word "Human" has the same imposed meaning, since it originates from a PIE word "*ǵʰmṓ" "earthling" < "*dʰéǵʰōm" "earth". Compare Latin "homo" "human" and "humus" "earth, soil". Its modern use in science fiction literature contrasts "Earth" (the planet) with outer space or hypothetical other planets with sapient life. The term was often used in 1950s science fiction film and novels by aliens to express a disdainful