[fremont_steve]

Well - let's see - 10 tons...hmmm..

If I recall, the extended heavy lift vehicle that is under development has a capacity of 100 tons. Let's say $100 million for the launch. Let's assume 20 tons for the support vehicle + 8 "rods from God."

Now I found the "fly-away" cost of the Minuteman III ICBM at 7.88 million dollars.

So 8 * 8 million dollars (rounded up for easier math) would run about $64 million for 8 stand-alone missiles versus the the $100 million (guesstimate) of 8 "rods from God."

So the 8 standalone missiles (with multiple war heads) costs about 6/10's of the "Rod from God" solution. It's certainly cheaper. The problem here is that you have to put a nuclear warhead on the top of the missle to get a big bang... whereas the "Rod from God" is non-nuclear and only does alot of damage via kinetic kill.

Point is that the price is a bit higher, but isn't THAT out of reach as a weapons system. For heaven's sake. The cost of a single B2 was 0.5 BILLION (that's with a B). You could have 40 "Rods from God" orbiting for the cost of one B2.

[SENTINEL]

You forgot about the weight of the extra fuel to decelerate the rod. I'll bet to be feasible, these things need a steep reentry which would require a large impulse. Seems like 30-50% the weight of the launch fuel requirement per pound.

Don't get me wrong, I'm all for space based weapons, I just think that even something more like standard smart bombs with heat shields and deceleration motors to slow them out of orbit would be more bang for the buck than tungsten rods. Less kinetic and more chemical energy would lower the cost and complexity, IMO.