>If you want to hit the atmosphere in minutes instead of 1.5 hours, you need to pay a price in delta v, but you don't have a problem with the control at hyperso

>If you want to hit the atmosphere in minutes instead of 1.5 hours, you need to pay a price in delta v, but you don't have a problem with the control at hypersonic speeds - we are still in vacuum. Once you hit the atmosphere you need control to hit the target, not to get to the target faster. If you're in low orbit you'll drop into the atmosphere almost immediately when you burn retrograde. And you can hit your target faster by entering the atmosphere later than you otherwise would and steering down. The question is when you really have enough control to make that happen. >Now let's see what happens if you put a few dozen or hundred in space. What can you do with a single Rod? The earth turns. Within 24 hours all your rods will have been in a position to hit any target on the surface. >But in terms of military targets, what good are these? Remember, they are tiny in comparison with nuclear weapons. You can't destroy nuclear bunkers, you can't acquire mobile targets. You could most certainly destroy missile bunkers if your targeting was accurate enough even with a relatively small rod. But there's no reason to assume the rods are small - 50 tons is a nice round number. Assuming you can't get volume pricing SpaceX will loft 100 of them for about the price of a carrier. And I don't see why you think you couldn't hit a moving target (assuming there exists a moving target worth destroying that way). The MRBM missile the Chinese have developed to destroy carriers can hit a moving target, and that's substantially the same bit of engineering. >If someone could solve the mobile target acquisition problem, these would be really good at killing tanks and armored vehicles. As I pointed out, this is already a solved problem. That said, it would be pointless to use something that expensive to destroy a tank. There are all sorts of ways to kill tanks and armored vehicles for a tiny, tiny, tiny (and that's not really enough "tinys") fraction of the cost. You're already a sitting duck in a tank. No, the role for the Rods would be strategic - bunkers, ports, airfields.