Everything about this mission could have been modeled on a computer. The Laws of Physics work in space as well as on the Earth.
The only variable they couldn’t model is “Can they actually hit it?”
But this rock is in a known orbit, and probably has been for millennia.
A dangerous rock is one that suddenly comes in from the outer fringes and intersects Earth’s orbit at a collision point.
THEN you have to do all kinds of calculations to get the trajectory and speed exactly right and the calculations to intersect that rock at exactly the right time and angle, with enough mass to either destroy it or nudge it into a different trajectory......................
But it was computer modeling that gave us the phony global warming scam and its offshoot climate change, remember?
I have suggested for many years that asteroids of that type should have a rocket motor landed on them, to be fired at the appropriate time to change its trajectory to miss Earth by at least one moon’s distance. It would be more predictable than the results of crashing something into it.