Re:Coaxing vs Pushing (Score 1)

Isn't the point that the coaxing can be dynamically controlled and thus allows for greater precision?

The 'keyhole' that they are talking about must actually be in phase-space (position-velocity coords, not just 'space'-space). The earth-collision trajectories and the accesible non-collision trajectories are probably close together in phase space. The initial collision is somewhat unpredictable so there's a risk of making things worse ... plus secondary collision adjustments are going to be quite hard since the object has moved in an unpredictable way and the path that you picked a few years ago may be way off. Cleverly matching the asteroids post-collision trajectory seems like the most robust thing to do.

Those are just my quick guesses as to what's going on.