With such an outpost, NASA could learn to use the moon's natural resources to live off the land, make preparations for a journey to Mars, and conduct a wide range of scientific investigations.

As currently envisioned, an incremental buildup would begin with four-person crews making several seven-day visits to the moon until their power supplies, rovers and living quarters are operational.

At that point, missions would be extended to two weeks, then two months and ultimately to 180 days. Over the first decade of lunar habitation, space travelers would learn the techniques and skills needed for the eventual journey to Mars.

One team of experts from NASA's Langley Research Center, NASA's Johnson Space Center and NASA contractor ILC Dover LP is looking at inflation-deployed expandable structures as one possible building block for a lunar base.

According to NASA "Inflatables" could be used as connectors or tunnels between crew quarters and can provide radiation shelter if covered with lunar soil. Inflatable space structures are already under development and the first test was conducted last year with several more planned for 2007-8. Eventually these structures will be used as space hotels for tourists.  

As a starting point, ILC Dover has delivered a 12-foot (3.65 meter) diameter inflatable structure made of multilayer fabric to Langley for ground-based evaluation of emerging technologies such as flexible structural health monitoring systems, self-healing materials and radiation protective materials. Attached to the structure is a smaller inflatable structure that serves as a demonstration airlock. Both are essentially pressurized cylinders, connected by an airtight door.

The "planetary surface habitat and airlock unit" can also be used to evaluate materials, lightweight structure technologies, astronaut interfaces, dust mitigation techniques, and function with robotics and other lunar surface equipment.

The image shows the "planetary surface habitat and airlock unit" has been delivered to NASA for ground-based evaluation of emerging technologies such as health monitoring of flexible structures.