Future battleships

I toured an aircraft carrier and while it was an awesome experience it made me sad to think about the demise of the battleship. However, aircraft carrier based navies, largely aren't compatible with a battleship-centric projection of national power. Aircraft carriers aren't going anywhere, but with unmanned aircraft being used more and more, the role of the super carrier will decrease and smaller more numerous carriers built to support primarily helicopter and UAV operations will become key to supporting the distributed battlefields of the future.  We cannot as a nation afford 12 Ford class carriers but we cannot afford not to have a large number of carrier groups.

However, it was not my goal to armchair QB Naval policy; I wanted to talk about the return of the battleship. The battleship of the future will not have 18" gun batteries. It will have massive reactors to feed banks of rail guns or other kinetic projectile systems, firing rounds several hundred miles, at the cost of a few grand per shot, with a sustained fire rate of less than minute between rounds. (Right now the Army is using artillery rounds that cost over a hundred grand each, and they do not fly several hundred miles so this would be a bargain.)

To create a low pressure atmospheric conduit for the rounds from the guns to ride in without melting or decelerating, the future battleship will have to have batteries of high power lasers. The lasers will fire before and during the acceleration of projectiles in the gun to heat or convert the air in the rounds projected trajectory to plasma. It is reasonable to think that with lasers this powerful they would be great offensive weapons, but lasers are line of sight weapons and that is very limiting for a weapons system. Lasers are perfect for defensive purposes, the lasers will fire at or around the incoming missile creating super heated air pockets and shockwaves to destabilize or damage it. A direct hit while preferred would be unnecessary, since an object traveling fast enough and low enough to avoid radar guided autocannon fire would be unlikely to recover from a large loss of stability event caused by a big change in air pressure on the control surfaces. Aircraft which are larger and slower could be destroyed as soon as they crossed the horizon. Ballistic objects would be easy prey too, since some of the laser energy would be used to destroy the incoming object and rest would steer the debris away since the energy of impact would still be very damaging. (The laser thing might seem farfetched, but the Navy is currently deploying lasers on ships to destroy ships and aircraft.)

The role of the future battleship would be similar to their role in WWI and WWII bombardment of land targets and the destruction of mobile targets. The difference would be that the ship could sit 200 miles off shore and the shells can still impact 100+ miles inland. When/if such a battleship can be built it would be a second golden age of navel warfare.

You might be thinking why not just build the same kinetic impactor/laser based system on land but make it super powerful? Super powerful rail guns would probably be built, but they would be used fire bulk cargo (water, food, raw materials, etc) into space to support a moon base or other extra-orbital missions. The reason land based rail guns wouldn’t be built as military weapons is the same that land based superguns always fail; they aren't mobile so they can be overwhelmed and destroyed at the enemy’s leisure.