The angle of attack would be wrong for penetration, unless it dove in. It needs to be dropped from something like 50,000 feet to achieve sufficient velocity.
Terminal velocity must be pretty ding-dang fast!
Yeah, you can’t just shove a MOP out the back of a cargo plane. It would probably take at least a few MOPs impacting the same spot to have a reasonable chance of success anyway.
Terminal velocity occurs when the forces of gravity and drag are balanced, resulting in terminal velocity. It doesn’t take 50k’ to do that.