Navy Experimental Rail Gun to Fire GPS-Guided Projectiles

I guess I don't see the true purpose of this. when we have missiles the can go hundreds and hundreds of thousands of miles what do we need a magnetic railgun. I guess I may be uneducated about it. could somebody please explain to me why is this such a big deal when we have bigger things in our arsenal that can do greater damage. is it a radar thing?

Missiles can be detected and shot down by weapons such as the Phalanx CIWS and are dangerous to be carrying around in case of attack. By using railguns that use no explosives they have no risk of the munitions detonating in an attack. And the shells for the railguns are probably far cheaper.

That's great news, missiles weigh a lot, and are storage problems if you can reduce that storage down to 30 pounds and increase the impact speed of the projectile to deliver it on target then you have a devastating weapon. It's a small one but a very useful one, and as the rail guns get more capable then they can be used as a first stage to orbit of microsatellites.

Now a nuclear powered aircraft carrier could easily provide the energy. The energy would be stored in supercapacitors and the energy would be released at one time so even though it is a great amount of energy it can be built up and stored for hours before being used.

Ron Bennett

@ author,

This statement is incorrect, "Electromagnetic rail guns use powerful magnets lined up in series along the length of a cannon". That you described is a "coil gun".

A railgun comprises a pair of parallel conducting rails, along which a sliding armature is accelerated by the electromagnetic effects of a current that flows down one rail, into the armature and then back along the other rail. (Wikipedia). Also see "Homopolar motor"

Please check your facts more carefully.

@jonny5ive

Rubiconnn & Ron Bennett covered pretty much all the points FOR having an Railgun

But imho the most important point is Cost-Per-Shot.

A projectile that's damn near impossible to stop, insanely accurate, very long range and with very high kinetic energy (read: KA-BLUM!) can be duplicated by any number of complex munitions (e.g. Missiles, JDAMs ferried by fuel slurping jets and the like)

But one that can be done on the cheap of this scale is something that ONLY a railgun can bring to the table.

Why do wars cost the US so damn much? Part of (a LARGE part of actually) the reason is because the US has a penchant for hurling ALOT of VERY expensive pieces of single use munitions at guys with ak-47s (ok gross oversimplification, but you get my drift) huddled in a cave in the middle of the desert.

To illustrate this point I shall paint you a hypothetical and and super simplified 'gamer' type picture.

To win XX war, you must do 100,000 dmg to enemy

You have:

Tomahawk Missile
Cost per shot: $569,000 (Lowest end version)
Dmg per shot: 1000

JDAMs fired by F-22
Cost per shot: $27,000 (Not including cost of F-22 and fuel)
Dmg per shot: 300

Railgun
Cost per shot: $900 (Estimated cost of projectile and power)
Dmg per shot: 1000

I don't think i need to explain further which weapon you would use to win the war. :)

Thank you all for the great explanation. cost effectiveness and little if no loss of explosive power makes sense. very informative. thanks again.

@cholin3947

THANK YOU...

Even a 'coil gun' would probably require the specification of 'ELECTROmagnet' for that to be accurate.

Intelligent smart GPS guided rounds, this is great information! I like to see new pictures of the rail gun and new videos PoPSCi, rather than the same old stuff.

I think a primary advantage, which no one has covered here is time on target. At Mach 8 a projectile will take a far shorter time to hit a target then a cruise missile will (Seconds versus minutes). Very handy if you are looking to hit a moving target. The kinetic energy is something akin to a 2000lb bomb.

I am somewhat concerned about using GPS though as several news stories have recently indicated that GPS is fairly easy to spoof, making this type of guidance less effective.

Good points timias, I am aware of fire control systems that can turn or flip the enemies incoming missles. I imagine the same might be done to this as well.

If GPS fails to get the target to where it is going these things can be laser guided too. Rounds like that exist now.

Round not target. My Bad.

I'm not so sure about the cost, once GPS guidance is added. If you look at the cost of an Excalibur GPS-guided 155MM round, that costs about $50,000. Don't know what a normal 155MM round costs today, but I'm pretty sure its well under $1000. This is the price of adding GPS.

And the railgun round will be accelerated far faster than an Excalibur, in all likelihood, exponentially increasing its price.

Also its important to know what the kinetic energy is of a shell over distance. Obviously after 200 miles of travel, the railgun round not be impacting at anywhere near 5600 mph.

This is not to say that this could turn out to be an awesome weapon.

Unless someone changed the laws of physics, a GPS guided rail gun is impossible. At Mach 8, the plasma sheath that would surround the round in flight would prevent the round from recieving GPS signals.

At what speed does the plasma sheath stop becoming a factor?

At Mach 8 the plasma shealth forms.

Nice job, D13.

Thank all of you for remembering the difference between a coil gun and a railgun. I don't want to be callous, but come on PopSci.

I actually have designed something a little bit more poweful than an ordinary everyday Zumwalt class. I designed what I think the next generation of naval warfare could be based on. I call it Leviathan.

SUbmersible aircraft carrier aremed with 48 cruisers and three, count 'em, railguns, positioned fore and aft. I thought of them being more like an NLOS cannon, getting the target and then compensating power and elevation accordingly. It was designed to work soley on the F-35 J/SF, and to launch off CV-22's at almost anywhere on Earth. How to power such a girl? Easy, SIXTEEN pebble-bed reactors, four for the railguns only, two for back up power. Rest goes to engine power, making it relatively fast.

ANy engineers out there? I know it needs work, but I can't help myself. I love to invent.

And to anyone wanting to put one of these railguns on a sattalite, wiki "Rods of God"