NASA has begun to plot out its escape route from low Earth orbit, putting itself on a return journey back to the Moon, planting footprints on Mars, and heading off to other targets beyond.

In his mid-January space pep rally, President George W. Bush charged the agency with signing up to a new astronautical agenda -- part of which called for extended human missions to the Moon as early as 2015.

Not only NASA has the Moon in sight. Several commercial firms are ready to go the lunar distance too, perhaps giving the Moon the real business - as a tourist Mecca.

President Bush has established the goal of a human return to the Moon by 2020, as the launching point for missions beyond -- particularly Mars. Beginning no later than 2008, the first in a series of robotic missions to the lunar surface are on tap to research and prepare for future human exploration.

Using a yet-to-be Crew Exploration Vehicle, the first piloted mission to the Moon is listed as early as 2015, with the goal of living and working there for increasingly longer periods of time.

The President explained in his January 14 vision statement at NASA Headquarters: "Returning to the Moon is an important step for our space program. Establishing an extended human presence on the Moon could vastly reduce the costs of further space exploration, making possible ever more ambitious missions. Lifting heavy spacecraft and fuel out of the Earth's gravity is expensive. Spacecraft assembled and provisioned on the Moon could escape its far lower gravity using far less energy, and thus, far less cost."

Bush continued by noting that the Moon is home to abundant resources. Its soil contains raw materials, he added, that might be harvested and processed into rocket fuel or breathable air.

"We can use our time on the Moon to develop and test new approaches and technologies and systems that will allow us to function in other, more challenging environments. The Moon is a logical step toward further progress and achievement," Bush said.

Setting up a home-away-from-home on the Moon is under active study at NASA. From inflatable bases, "wagon train" concepts to underground bunkers -- they are among an array of proposals evaluated over the years.

At last month’s Space Technology and Applications International Forum (STAIF) in Albuquerque, New Mexico, lunar base ideas past and present were offered by Marc Cohen of NASA’s Ames Research Center in Mountain View, California. He is an architect in the center’s Advanced Space Projects Branch.

One notion -- conceived by NASA’s John Mankins, a human and robotic technology specialist -- is a Habitat Robot, also dubbed "Habot" for short.

Habot is a radical departure from lunar base studies, Cohen noted. Habot modules would land on six movable legs, making use of those legs to strut their stuff robotically away from a lunar landing zone.

"With self-ambulating lunar base modules, it would be feasible to have each module separate itself from its retro-rocket thruster unit, and walk [miles] away from the landing zone to a pre-selected site. These walking modules can operate in an autonomous or teleoperated mode to navigate the lunar surface," Cohen reported.

On arrival at a predetermined site on the Moon, the six-legged walking modules can bond. That is, they combine and make pressure port connections among themselves. The result: a multi-module pressurized lunar base.

Moon-landing astronauts would find a ready-and-waiting base. Once the lunar explorers depart the scene, the Habots separate from each other to being their trek to a new address elsewhere on the Moon. It is also possible for crew members to go along for the ride in their mobile Habot.

"There have been hundreds of lunar base and habitat studies. We’ve learned a great deal from them," Cohen told SPACE.com . "The goal is to develop a much broader, sustainable, justified program of exploration."

To get to Mars, Cohen said, it is absolutely essential to rigorously test a variety of technologies beforehand – and the Moon offers such a testing ground.

Getting unpiloted spacecraft to Mars has proven difficult in the past. One out of three succeeds, Cohen said. "Even the most dedicated and courageous astronaut would think twice about going on a mission to Mars where the probability of getting their alive was only one-in-three…and that doesn’t even mention getting back."

The Moon can be utilized to problem solve at least three issues before leaping to Mars with humans, said Wendell Mendell, NASA Manager for the Office of Human Exploration Science at the Johnson Space Center in Houston, Texas.

"First of all, it’s really important to understand how the crew will perform on a mission to Mars. That trip is three years long," Mendell said. How that crew interacts and works with each other, plans daily operations, handle sickness, and other activities is critical to know ahead of time.

"So the Moon represents a place to really work on the crew," Mendell said.

A second issue is relationship between the crew and ground control.

"On a Mars mission, the crew is certainly going to be more autonomous. Because of the distances involved, you can’t really converse. You can send packets of messages, sort of like faxing," Mendell noted. "So there’s going to be a whole new mode of mission operations that has to be worked out and understood."

Lastly, there is need to fully shake-out all hardware as to reliability and servicing patterns, Mendell said.

All these and likely other items should be done on the Moon prior to Mars departure. Doing so would assure mission success and make certain the safe return of the crew to ticker tape parades back here on terra firma.

"If my ideas are true, then it implies we’re going to have some kind of facility on the Moon. It would be a place where people would stay for long periods of time. Some people might call that a lunar base," Mendell said.

But before any lunar outpost dots the Moon, there’s survey work to do.

Already swinging into high gear is NASA’s Goddard Space Flight Center in Greenbelt, Maryland. Scientists and engineers there have begun scoping out a Lunar Reconnaissance Orbiter to be launched in 2008.

Lunar work underway includes staff members at Goddard’s Earth Sciences Directorate looking intensively at the application of their terrestrial remote sensing hardware and software to the Moon. "There aren't any trees up there, but there may be useful applications in mapping lunar mineralogy," Paul Lowman, a scientist within Goddard’s Geodynamics Branch told SPACE.com .

One early list of Moon remote sensing jobs has been drafted, keyed to identifying indigenous resources on neighboring Luna.

For one, there’s need for a focused look at the Moon’s south and north polar regions to clarify the nature and extent of lunar hydrogen deposits, both ice and implanted solar wind hydrogen

Also a priority is using lunar orbiting radar, not only to peer into darkened craters in a search for water ice, but also to find safe landing sites. Similarly, a laser survey of the Moon’s polar regions is advised to help determine safe touchdown zones for future craft.

Meanwhile, at the Jet Propulsion Laboratory in Pasadena, California, engineers are talking about using a landing technique for the 2009 Mars Science Laboratory -- the Sky Crane -- to gently plop payloads onto the Moon.

Next page: Not another Apollo