Why it is so difficult!!! The Satellites orbits are well known. What degree they are stationed.
When I used stationary satellites, for ease of understanding, some clever Indian quickly jumped and thought I am talking of Geo Stationary satellites.
What I was referring to is the fact, all satellites at the time of lunch have their coordinates for their location in the space and its orbit. Otherwise we would have chaos in the space.
It is damn easy to hit a satellite with known orbital information. What is so hard in its calculation!!
How missile defense system work, don't they shot down incoming missiles, high in the atmosphere!!
It is more difficult than shooting down the satellite. For simple reason, the path i.e. orbit of the Satellite is very well known and you work on the calculation how to hit it.
While the path of incoming missiles is not known in advance, your anti missile system have to work instantaneously to work out its path, height , trajectory, speed etc. So many unknowns. While in Satellites case everything is known well in advance.
Therefore, it is piece of cake, for scientists.