This artist's concept shows a possible design for a future Mars habitat, created on the Martian surface with 3D printing. Any human habitat will need to be shielded from solar radiation and cosmic rays. A recent study found that astronauts would be exposed to high doses of X-rays during the trip to and from Mars. Mars has no global magnetic field and only a thin atmosphere to protect people on the surface. [NASA/SEArch+/Apis Cor]