A former NASA mission controller and space expert is raising new concerns that North Korea's missile program is aimed at launching a nuclear armed satellite at the U.S. where high-sky explosion would fry Washington and melt down the Mid-Atlantic electric grid, resulting in chaos and death.

Describing North Korea's missile program, Jim Oberg said that it appears the goal is to launch weaponized satellites, a fear the Pentagon has already started to prepare for.

"There have been fears expressed that North Korea might use a satellite to carry a small nuclear warhead into orbit and then detonate it over the United States for an EMP strike. These concerns seem extreme and require an astronomical scale of irrationality on the part of the regime," he wrote in Space Review.

Then, after describing a bizarre trip he took to North Korea to witness the program, he concluded, "The most frightening aspect, I've come to realize, is that exactly such a scale of insanity is now evident in the rest of their 'space program.'"

Similar concerns of an attack on the electric grid with an electromagnetic, or EMP, weapon have been raised for the last few years, notably from experts including Peter Pry and former CIA Director James Woolsey.

The endorsement of Oberg, a former NASA and U.S. Space Command official, adds a new and important voice and could spark a new push for anti-satellite defense.

It comes as North Korea is increasing their program and threats against South Korea, Japan and the U.S., as they did in the weekend missile launch condemned by Japan the U.S.

The threat is real, say the experts. What's more, it would be hard to prevent.

Oberg said that recent changes to the missile launch pad and efforts to conceal its program suggest action soon.

"These certainly don't convey the appearance of the features of a peaceful, harmless space program, and could possibly indicate something far more ominous," he wrote.

Based on his years in NASA Mission Control, he said that the projected orbit could put the satellite on top of Washington. "On the very first pass around Earth, after crossing near Antarctica, the satellite tracks northwards off the west coast of South America, over the Caribbean, and right up the US East Coast. Sixty-five minutes after launch, it's passing a few hundred miles west of Washington D.C. And with a minor steering adjustment during launch it could pass right overhead," he wrote.

"What might be inside that half-ton package is literally anybody's guess. That is might be a functioning applications satellite for the betterment of the population is harder and harder to believe. That it might be something harmful—and no heat shield would be needed if it were supposed to be triggered in space—is getting terrifyingly easier to consider. So knowing what's aboard that satellite becomes a vital issue of national security. And my personal experience in North Korea on that very question troubles me more and more," he wrote in a column being distributed in intelligence circles.

Oberg called for an intense intelligence program to watch North Korea and stop any satellite. He wrote:

In my view, the US needs to consider whether we can ever risk letting an absolutely unknown payload from North Korea ever fly across the United States again, and how we can be confident that the next satellite launch is carrying a non-hazardous cargo. For our once-in-a-lifetime visit in 2012, the North Koreans promised to prove their peaceful intent, and failed. We still need that promise to be fulfilled.

Somebody we can trust needs to be watching whatever the North Koreans mount on their next satellite rocket. Or we have to be ready to act based on valid suspicions and on the potentially all-too-terrible cost of relying entirely on hoping for the best from a madman.

Paul Bedard, the Washington Examiner's "Washington Secrets" columnist, can be contacted at pbedard@washingtonexaminer.com