Originally Posted by Shiva_TD

To prevent an asteroid impact?

We already have the technology to avoid it but we don't have the specific hardware for the job. We've had the technology for at least three decades.

It is not hard to gently nudge an asteroid in space so that it misses the Earth. At the right time even a change of 1/1000th of a degree would result in an asteroid missing Earth by 100's of thousands of miles.