See inside a moon simulator here on Earth

This is HI-SEAS, Hawaii Space Exploration Analog and Simulation, a white dome situated on the top of Mauna Loa on the Big Island of Hawaii. It's used to help prepare would-be astronauts for life on the moon or Mars.

The dome has been around since 2013 and can house six astronauts at a time. It's 36 feet in diameter and has about 1,200 square feet of living space.

On the site of an abandoned quarry, there's very little vegetation and lots of lava rock.

Pass through this door into the airlock, then inside the habitat.

This is the other side of the airlock that you see from the inside of the habitat. To the left is a bulky traditional spacesuit model that has been worn as a prop on previous missions.

Looking up from the ground floor you'll see the sleeping quarters and one bathroom on the far left.

Inside each room is a bed, a small desk and lamp, seat and hooks for clothing.

The view from the second floor down to the entrance.

A view of the workstations on the ground floor. They're used by astronauts to log experiments or communicate with the outside world and Mission Control. Messages are generally delayed anywhere from a few seconds to over 20 minutes to simulate the actual delay from the moon or Mars.

A TV and some exercise equipment for astronauts to work out are found on the ground floor next to the workstations. There's also a single window to let light in and so they can see outside.

An iPad shows the status of parts of the habitat for crews to inspect.

One of the most important rooms in the habitat. This is the downstairs bathroom, complete with shower, urinal and composting toilet.

Everything from food to water is rationed, so astronauts only get 8 minutes of shower time per week. This sheet and stopwatch helps them keep track of how much they have used so far.

These batteries are charged from the solar panels outside the habitat.

The kitchen is fully stocked, except instead of regular food it's all freeze-dried (including things like peas, pineapple, carrots and even meat).

The shelf of freeze-dried food. Luckily, there are a lot of spices that can add flavor to food once it's been rehydrated.

To the left of the airlock is a workroom where astronauts suit up on missions to go outside on EVA, or extra vehicular activity.

Although these modified boiler suits aren't really what astronauts would wear on the moon or the red planet, they're still close enough to make you feel like you're really suiting up for space.

All the extra equipment you need to go on EVA. There are knee pads, hair nets like balaclavas and arm holsters to mount communication devices.

Some of the suits even have name tags on them, like this one from commander and HI-SEAS director Dr. Michaela Musilova.

Before going out on EVA, astronauts have this handy checklist to follow.

At the back of the habitat is a lab where astronauts can run experiments. 

These fertilizers in the lab will be used in a study to see what food can be grown.

The crew from a previous mission left behind a memento of their stay.