>>>>Some time ago Google had a similar idea using balloons: http://en.wikipedia.org/wiki/Project_Loon
>>>
>>>Have they given up on that ?
>>
>>The end of the Wiki article "History" section says as of March 2, 2015 a balloon had a 187 day endurance record. So it looks ongoing, at least at some low level.
>>
>>I imagine they now have world-leading knowledge of certain parts of the Earth's upper atmosphere.
>
>Seems to me that the main advantage of the solar powered idea is that if could maintain position - I assume the balloon option would depend on having enough up there so that one was always 'drifting' in the required area. OTOH, balloons would probably be far cheaper.

ISTR some cute tricks with balloons. For example, during the day, balloon warms, goes to higher altitude, drifts in one direction. At night, cools off, descends to lower altitude, travels back to start area in prevailing winds going in the opposite direction. Dunno if Google is playing with that.

>>>On Dmitry's concerns: there was recently a news item claiming untraced drones had been seen flying over several French nuclear power stations....
>>>The manufacturers of the drone that I've got are now apparently hard-wiring 'no fly zones' into the GPS control....
>>
>>http://www.cnn.com/2015/03/18/politics/white-house-drone-charges/
>>
>>As for the GPS no fly zones - seems to me quadcopter drones are modular. Keep the hardware platform, but swap out the flight controls if they don't let you go where you want.
>
>I think the idea is simply to help ordinary fliers to avoid inadvertently flying in controlled airspace - but all models I've seen can simply be flown in 'manual' mode by switching of the GPS guidance. I don't think it would be simple to bypass the guidance system in other ways - on most models all of the navigation logic is integrated into the main control board. Best bet would be to hack the update code to remove some of the no-fly zones. Also occurs to me that they're going to need quite a bit of ROM if they are going to include co-ordinates for all for the worlds controlled airspace :-}
>
>My guess is that we will see a lot more regulation applied to larger devices.

Integrated navigation - yes, I could see that in COTS units. OTOH a while back I browsed sites like http://diydrones.com/ and its related store, seems you can get literally anything you want and then mix & match.

Regulation - if I were paranoid I'd be concerned about anything that could lift a packet of ball bearings such that it could be ingested by a jet engine. I think authorities are wrestling with where to draw the line.