Operation Sailor Hat 1080p ᴴᴰ - 500 Ton Explosion. The rockets are fired because at the time they had no way of measuring the speed of the shock wave which was estimated the same speed that blast shoots into the air, so they send them at multiple angles because they knew how fast they were going.I slowed it down and keep in mind, those rockets are going tens of thousands of miles an hour. And that is how the speed used to be determined apparently.
