how much area is kept with no one surviving there when a misile is gonna be launched , as miscile can fall off

Answer 1

The area would depend on the size of the warhead on the missle. If the missle's blast radius is 500 yards then you would keep 1000 yards clear in all directions. And so on for stronger or weaker warheads.

Answer 2

Are you asking about rockets or missiles in general? The US had missile silos in the middile of Kansas, as well as in the mountains surrounding Sausalito, California. The catch here is that those missiles weren't going to be launched unless it was to counterstrike a Soviet attack, in which case, the lives of a few thousand people would be traded to save millions. Moreover, nuclear missiles would not explode in a launch failure, so damage is limited to that caused by the missile and its fuel.

Rockets for satellite launches are a different matter altogether. Here, no lives are worth the trade, so launches are invariably over water, for the US, and over uninhabited land for the Russians. A auto-destruct on such a rocket would simply dump debris over the ocean for a launch from Florida.

Answer 3

What? Is english your first or even 4th language? This is probably going to be the best answer you get. But hey, buck up. I get 2 points.