Images: NASA plans a city on the moon

Test engineer Alonzo Frost prepares a 16.5-inch model of a crew launch vehicle model being tested in the Aerodynamics Research Facility at the Marshall Space Flight Center, Huntsville, Ala. As many as 66 tests will be conducted in the 4-foot-long wind tunnel to help scientist study flight performance characteristics of the space exploration vehicles.

Photo by NASA/MSFC/D.Higginbotham