Three Mile Island in the rearview mirror

Several experts say that whether nuclear power flies again depends upon public opinion. And while a significant chunk of the American public has traditionally held a dim view of nuclear energy, there is evidence that opinions can change, at least in the face of a compelling need.

Five years after the Three Mile Island accident in Pennsylvania, a nonpartisan Field Institute poll found that roughly 61 percent of Californians opposed nuclear power. But a new poll, released this May, found that about 59 percent of Californians were in favor of building new nuclear plants.

Pollsters suggested the obvious: Rolling blackouts and soaring electricity bills had altered views.

Most space industry experts say there is no direct relationship between the fate of Bush's energy proposal -- which offers tax breaks to the nuclear energy industry and promises to re-evaluate a controversial limitation on reprocessing nuclear waste into reusable fuel -- and the potential for a nuclear powered space program.

But several of those interviewed by SPACE.com expressed optimism for a political and social trickle-down effect.

"In order to line up national support, we need a NASA mission or missions that would inspire Americans of all ages," says the University of New Mexico's El-Genk.

A potentially more difficult challenge also looms, especially regarding the construction of large-scale nuclear power plants to support Mars or lunar colonies.

Even if the social barriers were suddenly lifted, it is unclear how quickly NASA could ramp up the necessary technology, given that three decades worth of plans for nuclear propulsion and space-based power generation are stuffed away in dusty drawers around the country.

Professors are loath to bring the topic up, says El-Genk, and a generation of engineers who understood the technology is largely retired or dead.

"University education in this area is nil, due to the very low enrollment in nuclear engineering departments during the last two decades and the closure or combining of more than half the nuclear engineering departments that existed in the 80s," El-Genk told SPACE.com.

With this dying generation may die the dream of sending humans to Mars. Or, at the least, the dream might be deferred until a new generation of engineers can be re-educated.

So despite glimmers of hope within the space community, there is a realization that a tremendous public and political education effort would be needed to get nuclear energy off the ground and back into space.

Some worry the obstacle might be insurmountable.

Gary E. Mueller, an associate professor of nuclear engineering at the University of Missouri-Rolla, said he's hopeful that Bush's efforts will translate into increased use of nuclear power in space. But, tossing another obstacle into the equation, he says NASA will have to find new money to support research.

"Some leadership in Washington, which I hope the Bush administration will provide, and leadership at NASA, which will not happen with [Dan] Goldin's administration, is needed to clear up and shift political will and public opinion," Mueller said.

If President Bush were to push for a nuclear-powered space program, the effort would have a familial echo.

Bush's father spoke in 1989, on the 20th anniversary of the first Moon landing, of America's need to return to the Moon and lay plans for putting humans on Mars. His speech set no dates but spawned a flurry of studies and committees, resulting in recommendations that included nuclear power as a cornerstone for any possible Mars missions.

Twelve years later, there are still no plans for a humans-to-Mars mission. And though space-based nuclear power may be on the brink of a return to the political spotlight, it is also an idea with an uncertain future.