Astronaut offers idea to deflect asteroids

WASHINGTON — In this lifetime, there's a 10 percent chance, not just for snow, sun or sleet, but for a 60-meter asteroid to strike some part of Earth.

The 10 megatons of energy generated by the impact could do the damage of 700 Hiroshima-size bombs blasted simultaneously, said Edward Lu, a NASA astronaut.

Lu is also president of the B612 Foundation, a nonprofit, private organization attempting to "significantly alter the orbit of an asteroid in a controlled manner by 2015," according to the group's Web site.

Lu and other researchers testified last week before the Senate Subcommittee on Science, Technology and Space, which is considering "whether Congress should pass legislation to do something about this threat from space," said Sen. Sam Brownback, R-Kan., the committee chairman.

Lu said technology exists to counteract what Brownback described as a "real or perceived" danger in the public mind.

Lu proposed a $1 billion test that would deflect an asteroid by using a nuclear-powered spacecraft. Lu said the government should choose a small asteroid with a trajectory not headed toward Earth for a test.

Lu said the plan would be to fly to an asteroid, attach to it and provide continuous thrust that would "slowly alter" the asteroid's velocity, putting the rock on a new path, Lu said.

Two asteroids have hit Earth in the past century, blasting a region of Siberia in 1908 and an unpopulated part of Brazil in 1947.

Since 1998, Congress has appropriated $4 million annually to detect at least 90 percent of near Earth objects measuring at least a kilometer across. The project, known as Spaceguard Survey, aims to predict these asteroids' future orbits by 2008.

So far, the project has tracked more than 700 of about 1,100 such asteroids. Smaller asteroids also could be dangerous.