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Issue 05/19/11 - Vol. 42, Issue 19

Navy Blue Secrets
by Kent Ballard

In the American press, the U.S. Air Force usually steals all the thunder when it comes to new weapons development. The Stealth fighter, the B-2 bomber, and now the new F-22 Raptor and F-35 Lightning captured—and continue to hold—the public's attention. For the most part, they deserve it. I'm thankful this particular Air Force is ours and not somebody else's. It would be dreadful to think of these aircraft belonging to an unfriendly nation. It's also fun to speculate on what they're flying around that we don't even know about yet. The SR-71 Blackbird was kept Top Secret for decades after it became operational, no doubt puzzling and even frightening radar operators around the world who simply knew no human aircraft could fly that high or fast.

I think it would be great fun to peek inside a half-dozen or so secret Air Force hangers and have a close look at whatever mind-blowing craft they have today. But then they'd have to shoot me, so maybe that wouldn't be such a good idea after all. Air Force security frowns on writers snooping around their black projects.

Yet, while the Air Force has cornered the majority of the public's attention, our Navy has been up to some pretty incredible things themselves. When I say “incredible,” I'm talking about a vastly new and more capable Navy and Marine Corps in the very near future, just over the horizon. And while I'm sure the Navy has its own black projects, a surprising number of them are merely “dark blue,” navy blue if you prefer. While it seems if the Air Force develops a new tire for landing gear, they immediately classify it, the Navy's been much different. They've cheerfully allowed science and military writers to get a good look at some of their new technology—and friends, what they're working on is so wild, so unexpected, it can only be described as breakthrough technology. What we now think of as naval armament is about to become as obsolete as a rotary dial telephone.

For decades, science fiction writers have armed their imaginary spaceships with guns that needed no gunpowder to fire a projectile, and projectiles that don't contain explosives. All kinds of fanciful names were given to them; “electro-guns,” “mass drivers,” “Gauss rifles,” and “kinetic energy weapons.” SF writers, always scrambling for some imaginary new weapon, knew that if you lay a magnet on a table and push another magnet towards it, they will either attract or repel each other, depending on which way you laid the magnets. This mysterious but well-known action became “weaponized” as early as 1897 by John Munro, in his SF novel “A Trip To Venus.” They had developed electromagnets by then, and forward thinkers realized such magnets could be turned off and on, and even reverse polarity—and do it very fast. And once again it's being proven that if humans can imagine a thing, later humans will figure out a way to build one.

As you've probably guessed, among the first real-world applications of this were the magnetic levitation or “Maglev” trains of Japan and Europe. They don't ride on wheels. They literally hover just above their magnetic track and are pushed along by alternating magnets. Japan holds the world's speed record for their “bullet train” at  361 mph, pretty impressive for a magnet trick.

Somebody in the Navy must read science fiction, and one day turned to another sailor and asked, “Say, why don't we make one of those things?” (Don't laugh. Many a secret project had just that humble a birth.) Once looked at seriously, the problems seemed insurmountable. In the real world, a gun or cannon that could fire a shell magnetically would melt down midway through the first shot from mere friction. Steel couldn't possibly hold up to the heat generated. Then there was the power problem. It takes unholy amounts of electrical energy to get something moving at the speed of a real bullet. And then there were the magnets themselves. They'd overheat, melting any insulation around their wiring. And there was no way to control the energy being forced through the magnets at that speed. The precise control of the electrical components was far too quick for any kind of mechanical device to regulate them properly. It turned out to be a nice idea, but impossible.
After taking that into consideration, the Office of Naval Research set about to make it possible.

New materials development led to heat resistant “barrels” for magnetic cannon. New capacitors were designed to provide the enormous power required for containing the electrical energy. Computer controls mounted to lightspeed switches were devised. Ingenious cooling systems were drawn up. The Navy wasn't thinking small. They had in mind nothing less than replacing the great cannons that had been the main armament of warships since the 14th Century. Their physicists had already done the math and told them a working model of what they were tinkering with would be a game-changer in naval warfare. If they could make it fly fast enough, a two foot long chunk of almost anything weighing just a few pounds would have the same destructive power on-target as a cruise missile due to the kinetic energy it would hit with. No explosive warheads would be needed. The sheer speed of the  flying “chunk” would flatten a reinforced building. The Brits were working along these lines too, and in 2003 successfully fired a 1/8th scale model with very impressive results, so their Navy and ours began to collaborate on the project.

One of the first conventional ideas the Office of Naval Research (ONR) threw out the window was the idea of a round barrel. They could make the bore of their magnetic cannon barrel any shape they wanted because the “shell” wouldn't spin in the gun. This led them to experimenting with various-shaped gun barrels that would be able to transfer magnetic energy more efficiently than a round one. ONR experimented with triangular barrel muzzles before settling on a square barrel, which turned out to be the most efficient. There were various small-scale models fired, but as new materials kept being developed, new ways of harnessing the awesome electromagnetic energies, and the idea of firing the shell while surrounded in a “sabot” when in the gun itself was worked out. The sabot threw much more (tremendously more) power and speed into the shell, and once it left the barrel would simply peel itself off.

Here we need a word or two about physics. Don't be alarmed, there will be no test and I've already done the math for you. The multiplication of kinetic energy via speed is easy to demonstrate. Take two apples. Poke a hole through one with a sharp pencil. What happens? Well, not much, other than you have a small hole through your apple. Now take a 30-.06 rifle bullet, which is roughly the same diameter as your pencil, place it in a rifle and shoot through your second apple. What happens then?
It vaporizes.  Whyzatt? It's because the bullet transferred more kinetic energy into the apple due to its supersonic speed. So, the faster things go, the more energy they carry along with them and this kind of energy is called “kinetic” energy.  

We're going to wade a little deeper into the pool now, but remain calm. A “joule” is a unit that measures energy or work. The formula for deriving joules would scare a vampire, so we won't go there. (To make matters even worse, the formula is in the metric system.) So let's look at what one joule really is. It takes one joule of energy to lift a small apple one yard straight up. Or, one joule of energy is equivalent to a tennis ball moving 14 miles per hour. And like all terrifying math equations, you can flip this one around to determine how much work it takes to make a joule. If you can produce enough work to make one watt of electrical power for one second, yep, that's one joule's worth of energy. And I'm figuring that you already understand that a megajoule is one million joules. That tennis ball moving at 14 mph isn't so much, but a million of them all hitting a brick wall at the same time would knock it over.

Like I said, the Navy does not think small.

In early 2007, the Navy made a baby model of their science fiction gun for a test. It generated eight megajoules of energy and spat out a metal “brick”weighing just a hair over seven pounds at supersonic speed. It would have really, really ruined the day for anyone in front of it. Or a dump truck in front of it, for that matter. They blasted away with it for a period of time, taking measurements, speed readings, calculating the impact, and scaring the bejayzus out of people at the test facility who hadn't been informed when they were going to shoot it. Heads nodded all around. Yes, this thing had potential, all right.

Work continued, and in 2008 they built a little bigger one, setting more records. They fired rounds  weighing up to 22 pounds,  but they were unstable, being as aerodynamic as, well, a brick. Then, just this January, they cobbled together a model with more than four times the energy and loaded a projectile into the thing that Navy officials claimed looked like “a metallic icicle.” (It reminded me of an old 1950's science fiction rocket ship, complete with fins.) They ramped up the energy to 33 megajoules and let 'er rip. This time observers felt the ground shake. It came shrieking out of the end of the gun at hypersonic speed, punched a neat hole though a metal plate they'd set up in its way 100 yards down range, and then flew on straight as an arrow for seven more kilometers with no barrel elevation. The Railgun was born, so called because of the inner rails the projectile's sabot rides on during acceleration. Reporters invited to witness the test said they thought the electromagnetic gun would be silent. So what was that awful bang they heard? The Navy explained it was the sonic boom created by the projectile itself.

So they're satisfied, right? Nope. Again, that was just a toy, just a test model. The final model they're going to start placing on Navy ships around the end of this decade will be, most likely, of a classified “joule-rating” and range. But they'll be giants compared to the power of today's most powerful shipboard guns. Muzzle velocities of Mach 6 to 8 are within reach. Even so, the navy's ultimate stated goal is a speed of Mach 7.5 at the barrel and Mach 5 on target—up to 200+ miles down range with deadly accuracy. And a maximum range shot will take only six minutes to travel that 200 miles, arriving on target faster than a Tomahawk cruise missile.

That thing will be Thor's hammer to the enemy.

The Railgun is expected to mature to full power-- a staggering 64 megajoules-- by 2025. In the meantime some ships will have the 100 mile range version mounted to them. Compare this with the standard 5-inch gun now mounted on Navy destroyers. Their effective range is 13 miles, and maximum range is 15 miles. The Navy's new DD(X) destroyers will be all-electric, even down to the propulsion system. The massive generators on board will produce enough amperage to power these, and even more exotic weapons.

The Railgun will bring other benefits too. No longer will our warships need to carry tons of explosives, either as propellant or in the shells themselves. No powder magazines to explode, USS Arizona-style. No explosives for a shipboard fire to detonate. Faster response time on target. A Marine company needing fire support from a ship can have it delivered on target more quickly than firing missiles at it, and a destroyer will be able to cover them inland for ten times the distance. And a Tomahawk costs between $600,000 to around a million dollars per missile, depending on range, warhead, and guidance devices. The Railgun rounds can do the same amount of damage due to their horrendous kinetic energy (remember the apple you shot?) and will be spare change compared to that cost, plus a ship will be able to carry a great many more of them, and more safely.

Then we have the next-gen phenomenon known as “reactive materials.” Remember earlier in the article when I kept yammering about “new materials development?” Let me introduce you to the wonderful world of “reactive” materials. They come in various forms and types, but generally speaking you could have a crowbar made out of the stuff and toss it in a fire. Nothing would happen. You could beat your ex-spouse's car full of dents with it. Nothing would happen, at least not to the crowbar. You could run over it with a truck, drop it twenty stories out of a window,  shoot it with a shotgun. It would still be in the shape of a crowbar, and none the worse for wear.

But pack it in or around a high-explosive warhead or someplace where it would be exposed to outrageous energies, and—ta-da!--it becomes a very powerful explosive! Sure, you can take a ball peen hammer and pound on a block of plastic explosives all day long and nothing will happen either, but reactive materials (RM) have metallic properties. They have structural strength. You can make things out of them. You can't do that with C-4. And our navy blue friends at the ONR are busily finding all kinds of uses for them.

Whatever odds and ends the Navy shoots at bad guys are generally packed with explosives. Let's say a Naval aviator is in a life-or-death dogfight with a pair of those nasty Sukhoi Su-30MKs. He fires a Sidewinder and gets a good hit, splashing one. But he's now down to just one Sidewinder left and out of ammunition for his cannon (it's been a busy day for our aviator). His last missile simply must take out the other jet. He locks on, gets the tone, and fires. The Sukhoi pilot shoots off flares and they distract the heat-seeker in the Sidewinder. It closes and explodes, but it's not a direct hit. Shrapnel rips  through the fuselage of the Su-30, but does minimal damage and the enemy jet is still battle-worthy—and heavily armed.

This is not a good thing.

But let's say that Sidewinder is the next-generation model, one made out of that weird reactive material. The missile closes and detonates too far away for a regular kill, but the reactive material itself, the very shrapnel of the missile, becomes highly explosive, impacting the Sukhoi and viciously exploding again after ripping through the fuselage. Splash two, because shrapnel and fragments made of reactive material have a 500% greater lethality! Instead of peppering the enemy with shards of inert metal, it hits like a few dozen pounds of secondary explosives.
Okay, so now imagine a Railgun projectile made out of RM. Spooky, ain't it?

There's now a warhead almost ready to field called the “BattleAxe.” It will eliminate “soft” targets like trucks, thin-skinned vehicles, and hordes of enemy soldiers over a wide area. So what? you say. We already have cluster bombs. The big deal with the BattleAxe is that any fragment of it that does not explode goes inert again. In a cluster bomb, often several of the little “bomblettes” contained in the main bomb fail to detonate—but remain deadly. Advancing troops, civilians, even farm animals can set them off later by merely stumbling over one. There's a lot of collateral damage involved with using cluster bombs. Packing the main bomb with fist-sized pellets of reactive material eliminates this hazard. If three or four pellets don't detonate, you could play baseball with them. They won't hurt anybody.

Reactive materials are also capable of “dial-a-bomb” characteristics. In America's nuclear arsenal, many of our warheads are capable of being set to different detonation powers. They can be programed to explode at different energy levels, generally anywhere from 70 kilotons to 780 Kt. This has long been known in military circles as “dial-a-bomb,” a darkly humorous name for a very serious matter. God forbid we ever need any of them, but if we do the same nuclear weapons can be scaled up or down, depending on the target and situation. The Pentagon realizes there's no sense in using a large nuclear explosion when a much smaller one will destroy the target. This gives our arsenal, and our generals, a flexibility they may need in response to a nuclear attack.
ONR is working on land mines made primarily from reactive materials, “dial-a-mine” if you wish. Depending on the threat they're faced with in the field, Marines will be able to set the mines for various  levels of explosive power. Need to stop advancing tanks? Crank 'em up. But what about rampaging groups of hostile foreign civilians charging an embassy? Reactive materials will allow the Marines to set mines at such a low power level they actually become non-lethal weapons! They can merely knock people down, temporarily blind them with a brilliant flash, and maybe break a few bones and eardrums—but diplomatically, that's far better than simply killing them all. RM mines will give our Marines at the pointy end of the stick the capability to set their mines for the lowest power level needed, another option in our effort to reduce collateral damage and actually harm as few people as possible.

The Office of Naval Research is also developing an “active protection system” RM defensive gun-launched grenade that will take out incoming mortar rounds, RPGs and enemy grenades. On the other end of the scale, they're also working on large bombs filled with powdered reactive material which will “softly” explode and fill the air over a wide area with RM “dust,” then ignite it. The result would be an awesomely massive “thermobaric” explosion—and the thermobaric bombs we already have are considered “the next best thing to a nuke.” RM bombs of that nature could approach genuine low-kiloton nuclear explosions with no EMP, no radiation whatsoever, and no after-effects save for figuring out how to refill the giant crater where that enemy tank battalion was advancing.

At this point, if you love your freedom, you're probably thinking the ONR is well worth our tax dollars. But things that go “boom” are not the only futuristic weapons they'll soon put in the hands of our sailors and Marines. They've made breakthroughs on other weapons that do not measure their speed in Mach numbers. These work at the speed of light.

Current U.S. Navy ships are protected from enemy aircraft and missiles by their own batteries of surface-to-air missiles. Their last line of defense is the close-in Phalanx weapons system with a range of about 2,000 yards. Under sustained attack, it is conceivable that one of our ships could simply run out of ammunition for both. And while the Phalanx is incredibly fast and accurate, a supersonic anti-ship missile could cross that distance in a breath's time. The Phalanx is designed to engage multiple targets, but if the aggressor seriously wanted to take out a high-value target (an aircraft carrier, for example) the Phalanx could be facing swarms of missiles coming from different angles and directions.

The Navy needs ship defenses that do not run out of ammunition, have a much longer range, are easy to maintain, and powerful enough to destroy any incoming threat. Cruise missiles are bad enough, but with more and more nations (not all of them friendly) getting access to long range supersonic anti-ship missiles, we need to rethink our defenses.

Among all the physicists and engineers in the world who are working on lasers, the ONR arguably has the best. The term “breakthrough” is often over-used and terribly exaggerated, but the profound discoveries made by ONR in laser research defies the use of any lesser term. Quite simply, they're doing things now that just a very few years ago were considered physically impossible.

Our civilian hand-held laser pointers now come in a variety of colors; red, blue, green for example. A green laser pointer is sixty times more powerful than a red one, due to its energy consumption and the gain medium that's electrically charged to make the beam. The “gain medium” for early lasers was a ruby rod. Now they've learned to use garnet crystals and various gases and chemicals. All hand held laser pointers have an output power rated usually between 3 to 20 milliwatts. A very few range as high as 200mW. (One milliwatt is equal to one-thousandth of a watt.)

But military-grade lasers for use in warfare need to be at least 100 kilowatts, 34,000,000 times more powerful at the very minimum, to burn holes in enemy missiles or aircraft. If you had a hand-held laser capable of that (and was crazy enough to fire it), you'd vaporize a neat little hole through your wall and your pointer would immediately flash-fry you because conventional lasing also generates a tremendous amount of heat, most of which is wasted energy, never actually going into the beam.

It's no secret that engineers all over the world, both military and civilian, have been slowly ratcheting up the power of lasers over the years. Like Thomas Edison trying thousands of different fibers, metals, and materials, trying to find one that would remain intact long enough to make the light bulb practical, scientists have tried just about everything they could lay their hands on as “gain medium.” Some were better than others, some never worked at all, and a few led to other laboratory curiosities. But there seemed to be a physical limit to all of them, and none were what ONR was looking for.

The breakthrough came in 2004, when researchers at the Thomas Jefferson National Acceleration Facility hit upon a fantastic idea. If we can't find any gain medium that will do the job, why not get rid of gain medium altogether? They developed a process to fire a highly charged beam of electrons to initiate the lasing, then fed more power into that. The result was called the “Free Electron Laser” or FEL and it became known as the holy grail of laser research.

The FEL did things laser engineers could only previously dream about. Most high-powered lasers could only fire brief shots without needing to be shut down to allow them to cool, sometimes for hours. The FEL, well, you could turn it on and fire as long as you fed electricity into the thing. They also learned that a Free Electron Laser could be “tuned” to different wavelengths. This had them doing handsprings, because atmospheric conditions can vary wildly. To be effective, you'd need one wavelength for clear, dry weather, another for clouds and mist, still another to fire efficiently through rain. The FEL gave them an all-weather military-grade performance. And compared to other military lasers used in experiments, the FEL was easy to maintain and much smaller. They kept experimenting, ramping up the power, and finally fired the thing at an output of 10 kilowatts. When the nice people at the ONR heard about this, they got on the first jet to the Jefferson Facility. The ONR still needs a laser with ten times the power of the Jefferson FEL, but their breakthrough in lasing was farmed out to other defense contractors to see what their labs can do with it. In their own laboratories, ONR has built an FEL with a 14 kilowatt output—so far.

Previous experimental military lasers usually used chemical-powered beams, and some of them were outrageously powerful. But they were of such ridiculous size (and fuel appetite) that everyone knew they'd have to become orders of magnitude smaller and more efficient before they could ever be considered “weapons.” The Air Force did heroic work with its 747-mounted “flying laser” which used chemicals akin to rocket fuel for power. They charged head-on into a variety of lasing issues, and whipped several of them. In fact, they tracked and shot down two test missiles with their experimental plane. But even with a 747 full of electronics, flexible mirrors, and chemical fuel their laser was woefully short-ranged, subject to “jitters” from the movement of the aircraft and its engines, and underpowered. The Airborne Laser project was shelved by Defense Secretary Robert Gates in 2009.

Oddly, the first firing of a 100 kilowatt laser came out of older technology, used with a twist. Northrop Grumman built a unit containing 32 garnet crystal modules and combined them into “laser amplifier chains.” Then, in layman's terms, they focused these “chains” into one beam and finally broke the “100 kilowatt threshold,” firing a single laser beam at a record 105 kilowatts, well into the range the Navy was looking for. But can they “tune” the beam for different weather conditions? What about heating problems? I could find no information one way or the other. It's at this point where our navy blue secrets fade into black.

But the ONR takes pains to point out that lasers have many capabilities besides burning holes in enemy equipment. They can be used for rangefinders. You can communicate over laser beams. They can be used as sensors, and to guide the Navy's new Railgun shells. They also say that not every target requires 100Kw or more—some may only take 50, others just 20. It depends on what they're shooting at. At no point during research for this article did I find any mention of an upper limit to the laser power the Navy seeks, but I did come across the word.

And since Navy guards would just as cheerfully shoot me as Air Force guards if they caught me snooping around their labs, I'm not likely to find out any more until it's officially released to the press. We do know that shipboard lasers are still years away from being mounted on Navy vessels, perhaps a decade or more. And we know the 100Kw threshold was finally broken. And that research continues. Someday in the near future the Navy will begin launching the new DD(X) class destroyers, armed with Railguns, improved missile systems, and encircled with superpowerful laser defenses, each of the new “tin cans” far more deadly than a World War Two battleship. Or a fleet of them.