US Space Program, and also scientists who grew up on reading the novels. These include pioneers of space exploration research and the search for life on other planets. Scientist Carl Sagan read the books as a young boy, and they continued to affect his imagination into his adult years; he remembered Barsoom as a "world of ruined cities, planet girding canals, immense pumping stations—a feudal technological society". For two decades a map of the planet, as imagined by Burroughs, hung in the hallway outside of Sagan's office in Cornell University. Author-Illustrator Mark Rogers also lampooned the Barsoom series in the second Samurai Cat book. The novels based on the TSR Buck Rogers RPG has a military academy on Mars called the John Carter Academy, which one of the characters in the franchise goes to. For the novel's centennial anniversary, Library of America has published a hardcover edition based on the original book in April 2012 with an introduction by Junot Díaz (). There's also Lin Carter's Callisto stories which are partially a homage to John Carter. Themes The American frontier A Princess of Mars has many similarities to Westerns, including a desert setting, a heroine taken captive, and a showdown with the antagonist. Burroughs worked as a soldier at Fort Grant, Arizona, where he patrolled the desert to protect white settlers. During this time he gained a great respect for American Indians and their warriors, such as Geronimo. Barsoom resembles a kind of Martian Wild West. Indeed, John Carter is an adventuring frontiersman who is cornered by Apache warriors in the Arizona desert before his transition to Mars. When he arrives there, he discovers a savage, frontier world with scarce resources, where strength is respected, and where the civilized Red Martians maintain their racial vigor by repelling the constant attacks of the Green Martians. The latter are a barbaric, nomadic, tribal culture with many parallels to American Indians. A nostalgic desire to return to the frontier became a common theme in the United States during the early twentieth century. In the Disney movie John Carter, Bryan Cranston portrays a U.S. Cavalry Major who tries to convince John Carter to fight American Indians. As the nation become more urbanized, the 19th-century frontier was romanticized as a lost world of freedom and noble savagery. Similar ideas may be reflected in the fate of the ancient white race of Mars, which is mentioned