The Mars Ice Home is essentially an inflatable dome that can be filled with water—which will then freeze in the cold Martian air. That thick outer layer of ice would protect the interior from radiation, while a smaller dome inside would provide the actual living quarters. Since the outer dome is inflatable, and therefore compact and lightweight for the journey to the Red Planet, it can also be large. Living quarters don't need to be gigantic, so the extra space inside the ice dome could act as an icy yard. Astronauts could service equipment in the yard without having to wear pressurized suits, for example, since they'd just need an oxygen mask to breathe. The Clouds Architecture Office pitches it as "an undefined open space for contemplation, relaxation, exercise, game play or anything the crew decides to do" in its original proposal. So perhaps someday we'll be treated to pictures of contemplative astronauts playing low-gravity soccer in their ice yards.