Hang a right a few miles past the Dirty Devil River, bump down Cow Dung Road, and the barren, red landscape beyond morphs from mere desert into something, well, otherworldly. Men and women in spacesuits and oxygen tanks pick their way around boulders. One collects soil samples. Another launches a drone. Since 2001, the Mars Desert Research Station, a small complex that includes a laboratory, living quarters, observatories, a repair shop and a greenhouse, has served as a reliable stand-in for an actual base on Mars. The station is operated by the Mars Society, a collection of 10,000 space enthusiasts from more than 40 countries dedicated to exploring and settling the red planet. Researchers here pretend they are 140 million miles from Earth rather than seven miles from Duke’s Slickrock Grill and the Whispering Sands Motel in Hanksville. Now with NASA’s plan to land humans on Mars by 2033 and the promise of commercial space travel, interest in the station has soared. Engineers, physicians, geologists, astronomers, biologists and others come to test ideas related to living on Mars. Last month, more than 500 college students from 10 countries took part in the station’s annual Unive...