NASA's space habitat test in Arizona

NASA's space habitat test in Arizona

FLAGSTAFF, United States - Photo shows the dome-shaped Habitat Demonstration Unit (back) and a Space Exploration Vehicle, being developed by the U.S. National Aeronautics and Space Administration, during a field test of the devices at a desert in Flagstaff, Arizona, on Sept. 12, 2011. The HDU project aims to expand human presence beyond Earth.

NASA's space habitat test in Arizona

NASA's space habitat test in Arizona

FLAGSTAFF, United States - Photo shows a Space Exploration Vehicle (front) and the dome-shaped Habitat Demonstration Unit (back), being developed by the National Aeronautics and Space Administration, during a field test of the devices at a desert in Flagstaff, Arizona, on Sept. 12, 2011. The HDU project aims to expand human presence beyond Earth.

NASA's space habitat test in Arizona

NASA's space habitat test in Arizona

FLAGSTAFF, United States - Photo shows the dome-shaped Habitat Demonstration Unit (back) and a Space Exploration Vehicle, being developed by the U.S. National Aeronautics and Space Administration, during a field test of the devices at a desert in Flagstaff, Arizona, on Sept. 12, 2011. The HDU project aims to expand human presence beyond Earth. (Kyodo)

NASA's space habitat test in Arizona

NASA's space habitat test in Arizona

FLAGSTAFF, United States - Photo shows a Space Exploration Vehicle (front) and the dome-shaped Habitat Demonstration Unit (back), being developed by the National Aeronautics and Space Administration, during a field test of the devices at a desert in Flagstaff, Arizona, on Sept. 12, 2011. The HDU project aims to expand human presence beyond Earth. (Kyodo)