“Haha, it will put the once harmless asteroid on a new collision course with Earth?”
That is a very just and fair question. Considering gross incompetence.
“The mission is designed as a test run for planetary defense with the intention of proving that a deep space collision can alter the orbit of a space rock.”
If it is not designed to alter it how would they then know it did alter it? You can bet it has explosives and will alter it somehow. Away or towards is the question...
They need to stop playing with these things...
Once again, an example of the utter incompetence of our educational system. **Sigh**
At the speeds involved, the energy of the impact far exceeds that of any explosive that could be carried onboard, short of a nuclear weapon. Basically, DART is a kinetic weapon.
E = 1/2*M*(V^2). Or, see Heinlein "The Moon Is A Harsh Mistress".
If it is not designed to alter it how would they then know it did alter it?
Observation.
And, of course the idea is to alter the orbit. But, there are a lot of questions.
How accurately can we hit the asteroid?
Can we hit the center of mass? (An off-center of mass hit would tend to spin the asteroid, causing less deflection.)
How "spongy" is the asteroid? A hard splash on the surface sending debris to the "side" would impart less energy to the orbit change than a "softer" hit. (I'd guess we are talking about microsecond differences in the propogation of the explosion, but, basically we want to nudge the thing, not create fireworks.)
Is this asteroid a pile of gravel or dirty snowball we might split up or is it cohesive enough to stay together? (This also depends on the mass of the impactor and its speed relative to the asteroid.)
This asteroid is one of a binary pair. It should be interesting to see the effect on the orbit of the 2nd asteroid.
And so on.