If a dangerous asteroid appears to be on a collision course for Earth, one option is to send a spacecraft to destroy it with a nuclear warhead. Such a mission, which would cost about $1 billion, could be developed from work NASA is already funding, a prominent asteroid defense expert says.
Bong Wie, director of the Asteroid Deflection Research Center at Iowa State University, described the system his team is developing to attendees at the International Space Development Conference in La Jolla, Calif., on May 23. The annual National Space Society gathering attracted hundreds from the space industry around the world.
Source: Space.com. Read full article. (link)