Yeah... this kinda destroys the premise for me. We cannot create gravity, let along gravity projecting satellites.
Also, we do not have holograms. Why do all these movies (Ironman, I'm looking at you) and TV shows utilize stuff that doesn't exist yet to save the world? It takes me right out of what I'm watching.
Why can't we use realistic stuff, stuff we already have, to deflect or take out an incoming "earth-killer" asteroid?
Actually one of the realistic parts of the show is the gravity tractor spacecraft. That part is science, not fiction in this science fiction show.
https://www.nasa.gov/content/asteroid-grand-challenge/mitigate/gravity-tractor
You should complain about the EM drive.
Years to decades to reach a high velocity planet killer and then years to decades flying alongside it seems highly impractical. In a most-likely scenario where this object was only detected say 186 days before impact, would our theoretical technology that works on paper have enough time to work in the real world?
If it works, hey I'm all for it, but lets see it in action. Theoretical is one thing, actual possibility is another.
Gravity tractor doesn't create gravity like the OP is saying, it simply uses the gravity naturally created by the ship's mass. Thus, a large and very dense ship would do best.
Frankly, I think a ship with balanced, opposing thrusters on its sides (contradicting each other's thrust) would be far more effective, as the thrusters pointed toward the asteroid would be ejecting forceful gas that would "blow" the asteroid with FAR more force than the minuscule amount of gravity a ship's mass would ever exert. The gas would also work on a small cloud of objects and would not cause any significant danger of breakage to the asteroid or mass (plus, the thrusters could be set at a lower power if breakage is a concern).
Sounds like I should work at Nasa.