Group wants to practice altering the route of meteors

Daily Camera, April 3, 2005

For a short while last December, the Earth stood a 37-to-1 chance of being slammed in 2029 by a 400-yard-thick meteor named 2004 MN4.

Vegas.com's current odds on the Denver Nuggets winning the NBA championship are 50-to-1. And the Nuggets are playing well.

Were the asteroid to land on the Pepsi Center, it would vaporize the stadium and then

wipe out the entire Front Range, too.

Meteor 2004 MN4 will miss Earth, further observations have shown. But asteroids of its ilk hammer Earth once every 1,000 to 100,000 years. An asteroid 20 times larger probably wiped out the dinosaurs 65 million years ago.

Such threats were the impetus behind the all-volunteer B612 Foundation, whose leaders include two Boulder space scientists, Clark Chapman and Daniel Durda, both of the Southwest Research Institute. The group, named after the fictional home of Antoine de Saint Exupery's Little Prince, was founded in 2001.

It wants to land a spacecraft on an asteroid by 2015 and adjust its orbit - for practice.

"The last thing you want is to wait for the day you have to actually go out and push on an object to keep it from hitting us," Durda said.

The proposed mission plays on the same theme as the NEAR-Shoemaker spacecraft's landing on Eros, a 20-mile-long asteroid, in 2000. It would choose an asteroid more than about 200 meters across, land on it and push.

The engine would use nuclear electric propulsion, which involves a nuclear fission reactor generating electricity to fuel ion drives.

The craft would attach itself to the asteroid, which, given the near absence of gravity and the shaky structural integrity of many asteroids, could be a challenge.

The nuclear engine would fire up and run for a year or longer, its 100-horsepower thrust working like a swimmer frog-kicking against the QE2.

The idea is to change the asteroid's speed by about two-hundredths of a mile per hour, an imperceptible deceleration to a rock hurtling through space at 65,000 mph. But it would be enough to let the Earth slip by just ahead of the speeding projectile.

Why not just blow it up?

"If you break it into pieces, you may have to deal with them," Chapman said.

The group's plan could be done with current technology and about $1 billion.

The idea has landed in the lottery for NASA's Prometheus Program, which aims to demonstrate nuclear-electric propulsion for space exploration.

Donald Yeomans, who supervises the Solar System Dynamics Group at NASA's Jet Propulsion Laboratory in Pasadena, Calif., said in an e-mail that near-Earth asteroids aren't the greatest threat facing humanity.

But, he said, a recent NASA study suggested expanding the current $4 million-a-year program that seeks to detect threats larger than half a mile in diameter to asteroids as small as 150 yards wide.

Still, carrying out the mission the B612 Foundation hopes to see is another matter, he said.

Durda and the rest of the B612 group aren't giving up.

"It's time to actually go out and start experimenting and pushing on a real object and learn what it is we don't yet know," he said.