My girlfriend just asked a question that had not even occurred to me: what happens during a storm? I am sure Google's engineers have a way to handle that, but I am genuinely curious about what their solution is.
To avoid these two risks (storm and attack), I imagine it'd have to be at an altitude above weather currents and beyond shooting range... or be able to stabilize during a storm and be bulletproof.
If you don't mind that they get blown downwind sometimes, or that sometimes you have to ground them, or you just use them mostly during good weather or good seasons, or if they crash and you only lose equipment not people on board, then blimps can be viable.
Some parts of Africa might not even see a lot of seriously adverse weather.
What kind of defenses to you think the blimps will have to defend against these strikes? Some sort of armor plating on the underside would seem to be the minimum. Hopefully they'll be equipped with some offensive capabilities as well to combat and dissuade guerrilla and terrorist acts.
Or would it make more sense to just use expendable blimps, like a $10 balloon and a $20 router?
Um ... Google drones are the last thing we need. Enough problems with the military ones already.
Of course the warlords who might actually control some parts of these countries wouldn't have that ability nor would they care about shooting it down.
From http://en.wikipedia.org/wiki/High-altitude_airship it seems that the technology exists to put an airship above the jet stream and keep it in place for a long time. I don't know if that is their solution, but it would make a lot of sense.
"In November 2006, the U.S. Army bought an A380+ airship from American Blimp Corporation through a Systems level contract with Northrop Grumman and Booz Allen Hamilton. The airship started flight tests in late 2007, with a primary goal of carrying 2,500 lb (1,100 kg) of payload to an altitude of 15,000 ft (4,600 m) under remote control and autonomous waypoint navigation."
So it's perfectly possible for these things to typically fly a few kilometres above the ground. That is outside the range of small arms: the furthest confirmed sniper kill to date was at a range of 1,250 m.
So while it would certainly be possible for someone to shoot one of these airships down using aircraft or guided missiles, they would not be able to with small arms fire. Except during takeoff and landing, of course.
They're definitely not at risk to the odd potshot, but massed small arms/crew-served rifle fire could potentially be effective in the lower altitudes.
Also keep in mind that snipers are shooting at humans. That's a much, much harder target than a blimp.
And also don't forget the numbers I'm using suggest this is only plausible if you're firing more or less straight up, meaning the area you're ultimately targeting is where you are.