On a mission to Mars, future astronauts will have to leave the protection of Earth’s magnetic field. As they head into deep space, high-energy galactic cosmic rays will pass through the hull of their ship and into their bodies. This might have dangerous—and lasting—consequences for the astronauts’ health.
If we want to someday live on Mars, spaceships won’t be enough. We would need a Martian city—and this is how we might build one.