RAMON CRATER, Israel—From the door of the expedition base, a few small steps to the left an autonomous rover passes by. A few giant leaps to the right is an array of solar panels. The landscape is rocky, hilly, tinged with red. Purposefully it resembles Mars. Here, in the Ramon Crater in the desert of southern Israel, a team of six—five men and one woman— have begun simulating what it will be like to live for about a month on the red planet. Their AMADEE-20 habitat is tucked beneath a rocky outcrop. Inside they sleep, eat, and conduct experiments. Outside they wear mock space suits fitted with cameras, microphones, and self-contained breathing systems. “We have the motto of fail fast, fail cheap, and have a steep learning curve. Because for every mistake we make here on earth, we hope we don’t repeat it on Mars,” said Gernot Gromer, director of …