Today, after months of anticipation, three brave astronauts set foot on Mars—or rather, a darkened, sand-filled room designed to simulate Mars.

The explorers make up half the crew of the Mars500 mission, a project designed to study the psychological effects of a year-and-a-half long, deep-space voyage to the red planet.

Since June 2010 six men—three Russians, two Europeans, and one Chinese—have been living in isolation in a 19,423-cubic-foot (550-cubic-meter) “spaceship” outside Moscow, doing maintenance work, conducting experiments, and trying to stave off boredom by playing Rock Band and reading the complete works of Gabriel García Márquez.

The crew is made up of volunteers, some with no real-life space experience but all with applicable skills, such as engineering and medicine.

Read the rest at NationalGeographic.com