1) Prohibitively expensive. 2) Too many easily broken parts and too little fall-back mechanisms. (What do you do if it fails? You have to be able to reach the

1) Prohibitively expensive. 2) Too many easily broken parts and too little fall-back mechanisms. (What do you do if it fails? You have to be able to reach the nearest airport, which, over the big oceans, will be near-impossible without carrying at least half-a-journey full of energy anyway.) (Good luck getting something like this through certification..) 3) NIMBYs will try to stop you from darkening their skies. If you want to take the energy from next to earth, there will be additional energy influx (and you can put a global-warming equivalent on that). There are many more if I think for more than 10s.