ALBUQUERQUE, New Mexico – A NASA project to Jupiter and several of its moons may depend on the U.S. Navy to provide the nuclear know-how in building a reactor for deep space exploration.

NASA and the scientific community are considering adding a Europa lander to JIMO. The high-tech lander could make on-the-spot surface observations at the Jovian satellite. Europa is thought to harbor an ocean under its icy crust.

NASA as well as industry teams and other government agencies have begun to scope out how to build JIMO. Experts in nuclear-power technology gathered at the Space Technology and Applications International Forum (STAIF), held here February 8-11, to discuss how best to re-energize a nuclear space reactor program.

NASA’s Project Prometheus has the goal of developing a reactor-powered spacecraft. JIMO is being blueprinted to integrate this capability.

Discussions are underway between NASA and Naval Reactors -- located in the Department of Energy’s National Nuclear Security Administration -- to jointly build a space-rated nuclear reactor to be used for JIMO and other deep space missions.

Alan Newhouse, NASA Director of the Project Prometheus, told SPACE.com that high-level talks have been underway to iron out issues regarding Naval Reactors taking on the duties of fabricating a nuclear reactor for space.

Those meetings have involved the White House, the Department of Energy, Naval Reactors, NASA, as well as the Department of Defense.

A NASA-Naval Reactors go/no-go decision on the collaboration is expected shortly, Newhouse said. "We have finally reached the point where there are no more issues involved, with a couple of administrative details remaining," he said.

Naval Reactors has compiled an unparalleled record of success, Newhouse said.

As example, according to Naval Reactors, they are responsible for more than 100 operating nuclear reactors. Nuclear-powered warships visit some 150 ports around the world – critical to America’s forward-presence strategy and ability to project power.

The mission of Naval Reactors is to provide the Navy with safe, long-lived, militarily-effective nuclear propulsion plants in keeping with the nation's defense requirements, and to ensure their continued safe and reliable operation.

"Naval Reactors has embarked in the oceans of the Earth. Now we want them to embark in the ocean of space," Newhouse said.

NASA and space scientists have begun sketching out a JIMO-deployed Europa lander. But such a probe must be part of the now-projected 3,300 pounds (1,500 kilograms) of JIMO payload, Newhouse said.

There are issues revolving around such a Europa lander, Newhouse added, particularly planetary protection concerns.

First of all, a lander must undergo intensive sterilization. Moreover, there is need to assure that the lander’s energy source doesn’t warm up the moon’s icy environment, even melting through Europa’s frozen face.

"We don’t want to go there later on to find life and not know whether we had brought it in a previous trip," Newhouse said.

The science community involved in looking at the JIMO mission has strongly advocated a lander. A top science priority for a proposed Europa Surface Science Package (EESP) is astrobiology.

That's the view from a NASA Science Definition Team, reporting to the space agency in a February 13 report. The team's study was co-chaired by Ron Greeley of Arizona State University in Tempe, and Torrence Johnson of the Jet Propulsion Laboratory in Pasadena, California.

The NASA Science Definition Team's report to the space agency calls for a JIMO astrobiology goal: "To search for signs of past and present life and to characterize the habitability of the Jovian moons with emphasis on Europa."

"Many high-priority measurements can be made only from the surface of Europa," the report stresses. Once on Europa's ice-covered surface, the package's primary objectives would be "search for organic materials and determination of their composition(s); and "search for chemical patterns in any organics that might be indicative of biological origin," the just-released report suggests.

JIMO work is expected to enable other deep space missions.

The same technologies embedded within JIMO are also being eyed for a future mission to one of Saturn’s moons, Titan, as well as Neptune, the Kuiper Belt beyond it, and a voyage to discern the edge of the heliopause -- the boundary that separates Earth's solar system from interstellar space.

"JIMO is the pathfinder…to get through all the nuclear issues," Newhouse said.

Three lead industry contractors are vying for the JIMO work: Lockheed Martin Space and Strategic Missiles, Boeing NASA Systems, and Northrop Grumman Space Technology. In addition, representatives from more than one NASA field center, along with experts in government labs and agencies are overseeing technical issues too.

Newhouse said that by early 2005 one contractor will likely have been picked.

Although work is underway on JIMO based on a liftoff of 2011 or later, NASA planning charts show an unofficially announced slip to 2015.

At the moment, JIMO tips the scales at about 57,200 pounds (26,000 kilograms) –a whopping 29 tons.

The original flight plan called for JIMO to be rocketed into a nuclear safe orbit high above Earth. It would then spiral out on ion engines to reach Jupiter.

However, those two years of exposure to the space environment – rife with human-made orbital debris, meteoroids, and intense radiation belt hazards – are among issues that have moved NASA to consider putting JIMO on an escape velocity shortly after launch.

But doing so means more oomph from an Earth-to-orbit booster, including a high-energy second stage to send JIMO on its way.

Newhouse said that the sum of those hardware masses equates to about 110,000 pounds (50,000 kilograms). Lifting that much weight off Earth outstrips the capability of top-of-the-line Atlas 5 and Delta 4 Evolved Expendable Launch Vehicles (EELVs), he noted.

Now being studied for JIMO, Newhouse said, is use of a space shuttle derived vehicle – the Shuttle-C. If a heavy-lifter is a no show, then on-orbit assembly of JIMO is possible. In one such scenario, the spacecraft might be joined with a kick-stage motor after it first reaches Earth-orbit.