What astronauts should do first when they reach Mars

When someone steps off a spaceship onto the surface of Mars, the top priority—after the selfie—should be searching for life. That's the number one recommendation from a new National Academies of Sciences, Engineering, and Medicine report called A Science Strategy for the Human Exploration of Mars, co-chaired by planetary scientist Dr. Lindy Elkins-Tanton. But searching for life isn't an isolated goal. As Elkins-Tanton explains, "the samples and the investigations we need to do to search for life are also going to teach us so much more about Mars and also about habitability and what it's going to be like for humans there."

The mission architecture: short stays, long stays, and the human-robot partnership

The first human campaign to Mars would likely involve three missions. The first would be a 30-day stay—just long enough to confirm the equipment works, take initial measurements, collect samples, and absorb what it means to be on another planet. Two more missions would follow, either cargo deliveries or additional crewed missions, each building on the last.