Has anyone done a study about the usability of such a beast? Could be useful
against hardened targets if you could overcome problems like:

1: Size- you'd need a lotta motor to get a projectile to Mach 5 or higher
in the lower atmosphere.

2: Heating-keeping it from melting.

3: Guidance

4: Range

Maybe some of the technology from the old Sprint ABM missle could be
used. ISTR a proposal for AXE - a plan to use a MX/Peacekeeper
first stage as a booster for an area denial weapon (large quantity of
submunitions instead of upper stage(s)/warhead bus/RVs on top).

I would think that the ability to _accurately_ hit a hardened target
with a LARGE DU/tungsten/titanium penetrator would be very
handy indeed, even if you had to launch it by first dropping it
from a large transport craft, a la the C-141/Minuteman tests
of 25+ years ago!

Comments?

Bert