Model rocketry can be lots of fun, as can playing around with quadcopters, but after a while you'll probably be yearning for something a little more exciting. So Flite Test forum member "ukarmy04" decided to take the next logical step by mounting a platform for launching rockets on the top of a quadcopter, and sending them skyward as the 'copter hovers overhead.
Rather than simply slapping his rocket launch platform on the top of some quadcopter he had lying around, ukarmy04 built a special 'copter from scratch which he specifically designed for the task. To keep the center of gravity low, he slung the battery packs and controllers underneath the custom made wooden body. This left a large flat surface where he could mount the rocket launch platform, with a metal plate added to protect the wood from the rocket's blast. After all, you wouldn't want to whole thing to go up in some kind of airborne conflagration.
In the video below you can see how two of ukarmy04's test launches went, with three perspectives offered for each blastoff. First you see the launch from a camera on the ground, then one from a camera mounted on the quadcopter and finally the view from the rocket itself. Based on the launches shown in the video, it looks like the platform works pretty well. Despite being pushed down a bit by the force of the launching rocket, the quadcopter platform manages to stay impressively straight and stable.
Ukarmy04 says that the project was designed primarily as a proof of concept, rather than something which might have a practical use. The tests used a very lightweight rocket, and adding something more substantial would require a much bigger quadcopter. While it's hard to imagine how this technology could be used other than for fun, I'm sure the U.S. military could come up with something.