NASA Unveils $104 Billion Plan To Return to the Moon by 2018

Griffin said the choice of targets for moon landings "will be driven by science," but unlike Apollo, the program is also designed so astronauts can linger and establish permanent bases on the lunar surface to develop technologies and test techniques for a more ambitious, subsequent Mars mission.

The new propellants, for instance, will use both oxygen, which can be mined from Martian rocks, or methane, which can be extracted from components of the Martian atmosphere. "One reason to go back to the moon is to learn to live off the land to enable longer-duration space missions," said Georgia Institute of Technology research engineer Douglas Stanley, who led the "Exploration" study for NASA.

Logsdon described the project as "a good plan -- but not an elegant one" because it does not make much use of advanced technology. "It's a doable approach to getting people into space safely," he added.

But space policy and engineering consultant Charles Lurio, an advocate of innovative private-sector approaches to space travel, criticized the new proposal for being too "massive" and "unaffordable now and unsustainable later."

The moon mission will begin by putting into space a new 358-foot "cargo launch vehicle" weighing 6.4 million pounds. It lifts the moon rocket and the lunar lander into low Earth orbit to await the arrival of the crew exploration vehicle, the combined service module-crew module.

Both the heavy lifter and the "crew launch vehicle" that carries the spaceship use solid rocket boosters, like the shuttle, and fuel tanks derived from the external tanks whose foam shedding caused the loss of the shuttle Columbia in 2003. Loose foam will not be a problem for the new spacecraft, which are perched in traditional fashion atop the tanks, out of harm's way.

The exploration vehicle will mate in Earth's orbit with the lunar lander, then the moon rocket will ignite, carrying vehicle and lander on the three-day trip to lunar orbit. From then on, the mission will unreel in Apollo-like fashion, with the astronauts riding to the moon's surface aboard the lander, while the exploration vehicle orbits overhead.

Besides human space travel, the exploration vehicle can fly robotically, perhaps as a cargo carrier for a moon colony. It also could ferry crew and cargo to the international space station and dock autonomously there if necessary.

"The principal concern has always been the lunar mission," said Doug Young, program manager for the Northrop Grumman/Boeing team that is competing with Lockheed for the right to build the exploration vehicle. "But we've always known that we will ultimately have to meet the requirements" of the space station.