As epic making as the Apollo program of the late 1960s into the early 1970s was to lunar exploration, the Moon largely remains terra incognita.

The Moon beckons as a high priority port of call for further scientific and human exploration.

Furthermore, NASA is misdirected by setting its sights too firmly on Mars and the search for life on the red planet, said lunar scientist Paul Spudis. NASA's own Office of Space Science, as well as former space agency chief, Daniel Goldin, have "suppressed this [lunar science] community in favor of Mars," he said.

"I don't think you can conduct a human mission to Mars for less than a $100 billion in any time shorter than ten years," Spudis said. "The technology base will only marginally support a human Mars mission. It's just a bridge too far. I contend that NASA doesn't have a politically viable mission."

What is workable is sending back astronauts to the Moon, and doing it within 5 years. An initial mission could involve dispatching four people onto the lunar surface, and enabling them to stay for 45 days.

Spudis said that buried within NASA is a progressive plan for placing humans back onto the Moon. NASA Exploration Team (NExT) members at the Johnson Space Center, he said, have scripted a breakthrough strategy.

The NExT concept makes use of existing launch capability and existing technology to establish a staging point at a so-called Earth-Moon Lagrangian Point, L1. Here’s why L1 is important:

In each system of two heavy bodies (the Sun and Jupiter, or Earth and its Moon) there exist five theoretical points in space at which a third and small body, under the gravitational influence of the two large ones, will remain approximately at rest relative to them.

From the Earth-Moon L1 point, a window to any spot on the Moon is reachable with minimal rocket energy.

An ideal crew touchdown locale, Spudis added, is the rim of Shakleton crater near the Moon's South Pole. This setting is bathed in near-constant sunlight. Yet the site is close to sizable deposits of possible water ice tucked away in always-shadowed craters.

"I think it's the most valuable piece of real estate in the solar system," Spudis said. "This is the place to put the lunar base."

On a return leg back to Earth, astronauts could dwell at in their return vehicle or at a space port set up at the L1 gateway. They would wait for the proper timing, then perform an aerocapture maneuver at Earth, slowing down for a rendezvous with the International Space Station.

Spudis points out that as decades have passed, NASA has lost a lot of valuable experience as Apollo-era astronauts and managers have retired.

"No one at NASA has any direct experience with lunar flight," he said. "So why not give them some by going back to the Moon?"