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
Mars to Stay advocates—both favorable and critical—resulted in the Mars Artists Community creating several dozen more designs, with such slogans as, "Traitors Return to Earth" and "What Would Zheng He Do?" In October 2009, Eric Berger of the Houston Chronicle wrote of "Mars to Stay" as perhaps the only program that can revitalize the United States' space program: What if NASA could land astronauts on Mars in a decade, for not ridiculously more money than the $10 billion the agency spends annually on human spaceflight? It's possible ... relieving NASA of the need to send fuel and rocketry to blast humans off the