How many years away are we from a cheap drone that will takeoff, land, solar recharge, repeat until it returns to you a few weeks later with a few tb of SD cards of high res imagery?
Autel dragonfish and hanger and you're halfway there. Will need a fat checkbook (the bird is ~$200k) and be outside of the US.
A lot of the barriers are regulatory in the Western world. In rainforests you might not have to worry about that, but there aren't many shade free spots to land
Pretty close. Sesame Energy[0] make these shipping container boxes with solar panels + batteries so you can just drop them where you need no-supply chain energy. The boxes also synthesize hydrogen which can be used to power drones. The talk I heard from the CEO said the automated swapping of hydrogen canisters was not yet there, but they were working on it. Nothing in robotics is easy, but this feels like a very attainable goal that the military would pay to get working.
[0] https://www.sesame.solar/audience/us-military-allies