Some people on here talking about shotguns LOL, how lame. Yes, the altitude in most cases would be above 5,000 feet, take off and landing excluded and you are not getting within a mile of the airstrip.
For a viable solution, all you have to do is think critically and look at what is available in the consumer marketplace. This is really a no-brainer with a bit of electronics background and a reasonable bit of understanding in chemistry and metallurgy. Some questions to ask yourself;
How high do I have to go and what will get me there?
What are the physical launch requirements?
How do I identify an object and what signatures are available?
How do I maintain a trajectory and accelerate towards a moving object?
What kind of payload needs to be deployed?
The objectives have to be reduced into a series of questions. The questions have to answered with potential solutions. The solutions have to be examined and tested and where required or when viable, physically produced. The working solutions to specific questions/problems have to be integrated so a complete solution can be tested. Pretty simply right?
ETA: Just imagine if some foreign enemy force were attacking the US (or whatever western country you are in) and what potential solutions you could come up with to assist your government in knocking down enemy airborne assets. That's the position I am coming from here.
Cheers - Dave
edit on 5/30.2012 by bobs_uruncle because: (no reason given)