What's got six wheels and operates in very low gravity?

The answer: NASA's new lunar rover, informally called the "Chariot," which is currently being tested in two different configurations in the Arizona desert.

The rover basically looks like a big metal spider on wheels, and can be driven as such by a spacesuit-wearing astronaut.

Add a pressurized cabin, and it's a high-tech self-propelled Airstream trailer, with beds, a kitchen and a toilet.

The next step: to take the battery-powered vehicle out for a three-day spin by itself, without any support.

The rover is part of NASA's Constellation program, which aims to get astronauts back on the moon, permanently, by around 2020.

• Click here to read more about this on the National Geographic Web site.

• Click here for NASA's official lunar rover page.

• Click here for NASA's writeup on the current tests.

• Click here to visit FOXNews.com's Space Center.