The problem is that the energy you need to get the sand into retrograde orbit is *huge* since you have to cancel out the effects of the Earth's rotation.
Another problem is that orbital sand is a non-discriminatory weapon; it may take down your enemy's assets, but it will also take down your own and that of any neutrals as well. The latter are likely to become seriously p***ed off about the whole thing and might join forces against you.
Biting the hand that feeds IT
