your laser doesn't need to do anything to the balloon and can be as weak as a laser pointer. just aim at the cameras and zap the sensors. assuming the ability to aim and hold would be achievable at this level. who cares if it's just floating there if it is blind?
“Just aim” seems to be understating the challenge of hitting a tiny target through multiple miles of atmosphere and holding the same position long enough to damage the sensor. The laser alone seems like it would blow that $5k budget by a handy margin — not much economy of scale at that power level.
Yes, but damage is a function of power and time. If you can’t keep it on that a precise position you need to deliver far more power — there are links here to some research and they tend to be measured in seconds, which is a very aggressive target for something this far away through moving air.
edit, however, lasing a camera sensor doesn't need a lot of holding time. so just keep bouncing it around and hopefully, eventually you'll cover enough to render useless.
Remember, I’m not saying it’s impossible - just a lot more expensive. I’m sure the U.S. military budget could include powerful lasers, precision sensors, and the software to keep focused on a small target at a long distance but I’d be surprised if it wasn’t at least two orders of magnitude more expensive.
