NASA's 3D-printed Mars habitat in Texas prepares humans for life on the Red Planet.

Four volunteer test subjects will spend a year locked inside a 3D-printed simulated Mars habitat at the Nasa Johnson Space Center in Houston, starting this June, to learn the impact that a year in isolation with limited resources has on human health. The crew members will conduct experiments, grow food and exercise, and be tested regularly so scientists can learn what a year on Mars could do to the body and mind. The mission is Nasa’s next small step toward landing humans on the surface of Mars, which the agency hopes to achieve as early as the 2030s.