posted 03-08-2018 11:40 AM               

The Hypervelocity Asteroid Mitigation Mission for Emergency Response (HAMMER) spacecraft — a collaboration between the National Nuclear Security Administration, NASA, and two Energy Department weapons labs — would either steer its 8.8-ton bulk (called an "impactor") into a small asteroid, or carry a nuclear device to deflect a big one.

"If the asteroid is small enough, and we detect it early enough, we can do it with the impactor," physicist David Dearborn of the Lawrence Livermore National Laboratory told BuzzFeed News. "The impactor is not as flexible as the nuclear option when we really want to change the speed of the body in a hurry."

Just because these plans now exist does not mean the spacecraft will ever get built...