13.1.17

Railguns

With electromagnetic railgun systems (EMRS), “faster than a speeding bullet” takes on new meaning. The 32-megajoule – a measurement of power applied over a period of time, in this case equivalent to about nine kilowatt-hours – railgun in its second phase of testing by the Office of Naval Research (ONR) can fire a projectile at seven times the speed of sound (Mach 7), almost three times faster than an M16 rifle bullet. What’s more, the weapon achieves this blistering speed without the need for volatile, expensive, and heavy chemical propellants like gunpowder. This technology has attracted U.S. military planners’ interest. ONR tests of the 32-megajoule railgun at the Naval Surface Warfare Center Dahlgren Site in Virginia are aimed at eventual deployment of the weapon on new vessels like the Zumwalt-class destroyer, which produces the energy necessary to power the weapon. However, bringing this weapon of the future to the battlefield is not easy, and early hopes that the railgun could enter service by the end of this year now seem far-fetched. Given the progress made and the challenges ahead, what does the future hold for the military’s super gun?

The concept of EMRS is futuristic, but it is hardly new. French inventor Louis Fauchon-Villeplee filed the first patent for an “Electric Apparatus for Propelling Projectiles” nearly 100 years ago, and the idea has enjoyed periodic resurgences ever since. Most notably, during the 1980s, the Reagan administration’s “Star Wars” Strategic Defense Initiative hoped to use railguns to quickly intercept and destroy approaching ballistic missiles. However, until very recently, no one has been able to make the weapon practically viable. Put simply, the railgun is a large electrical circuit made up of three parts: the power source, two metal rails, and an armature, which is a piece of conductive material that creates a circuit between the two rails. Once activated, the gun draws an electrical pulse from the power source, which then runs up the positive rail, through the armature, and back to the power supply through the negative rail. This circuit creates two magnetic fields around the rails, which exert a perpendicular force on the armature – in most cases a “sabot” casing of conductive metal that carries the railgun’s primary projectile – and launches it out of the barrel.

In theory, this is all simple enough. However, getting this circuit to actually launch a supersonic projectile presents substantial challenges. First, keeping the railgun’s barrel to a manageable length requires pumping millions of amperes of electrical current into the rails to attain speeds of over Mach 5. This not only requires a large amount of power, it requires a system that can release megawatts of energy in a split second. As John Finkenaur, Director of Advanced Technology Programs at Raytheon’s Integrated Defense Systems tells The Cipher Brief, “it’s always a challenge to release that much energy at one time. Just getting to the point where you can fire once…is a real challenge.” Building a system that can store and deliver that power multiple times over, however, takes that challenge several steps further.

The second major challenge with implementing the railgun technology is simply building a weapon that can physically survive multiple shots. The barrel and rails, for instance, must be able to withstand the intense heat caused both by the electric current traveling through the rails, as well as friction from the armature traveling down the barrel at hypersonic speed. In addition, the magnetic fields surrounding the two rails conspire to exert enormous opposing forces and push the two rails apart. Finally, creating a projectile with electronic guidance systems that can survive this intense environment is extremely difficult. This is the case not least because, unlike conventional projectiles, which lose acceleration from the moment they are fired, the railgun projectile speeds up as it travels down the rails. Perfecting this projectile is especially difficult because, as President of the General Atomics Electromagnetic Systems Group (GA-EMS) Scott Forney observes, the railgun “projectile” is “actually a hybrid missile.” As such, it contains a variety of microelectronics, navigation control, and other internal systems that must be shielded against this tremendously hostile environment.

For these reasons and more, many have begun to doubt theories that what Deputy Secretary of Defense Robert Work described as a “set of railguns that would be inexpensive but have enormous deterrent value” could form a key layer in the Pentagon’s new “Third Offset” strategy. They argue that the power needs for the Navy’s designs are so great that only the 78-megawatt electric Zumwalt destroyer could use it – only three of these ships are being made – and that wear and tear could unreasonably limit the weapon’s use. However, for those involved in the development effort, such criticism is shortsighted. First, as Finkenaur notes, the railgun is a very adaptable system that “can scale the firing velocity of the projectile just by how much of the system you charge up.” This means that, using a pulsed power system like the one Raytheon has begun delivering to the Navy, railgun operators decide how much energy to plug into the rails and how many shots to store up in their batteries, depending on need.

Thus, even if a 32-megajoule (or more) railgun optimized for offensive naval surface fire support at ranges of over 100 miles is not feasible in the near term, EMR systems can still be highly effective at the 5-, 10-, or 20-megajoule range for a number of different roles, including missile defense. Due to its high launch velocity, the railgun is ideal for missile interception, and indeed, General Atomics already demonstrated a mobile land-based missile defense-focused version of its Blitzer railgun for the Army this April. Packed with precise navigation hardware and what Forney describes as “essentially a tungsten shotgun shell at the tip of the projectile,” this system can accurately intercept speeding missiles with “a tungsten shield.” At the end of the day, whatever the railgun’s power or range, its overriding advantage will always be cost. As Forney notes, when adversaries begin to threaten the U.S. with cheap missiles, possibly in swarms, “we will soon be able to respond with $25,000 hybrid missiles from a railgun rather than multimillion dollar conventional missiles.” Forney believes GA-EMS could field a system within three years, while Finkenaur guesses that five years is more realistic for a land-based system and ten years for the Navy. Until then, the Pentagon is focusing on shorter-range defensive capabilities. However, given its scalability, adaptability to different missions, and cost-effectiveness, it is only a matter of time before the electromagnetic railgun becomes an operational reality.


The concept of an electromagnetic railgun (EMR) is over 100 years old and has been posited as a revolutionary technology in fields ranging from missile defense, to lowering the cost of orbital launches and igniting fusion reactions. Today, the Office of Naval Research (ONR) is deep into the second phase of testing for a 32-megajoule railgun system that can launch a projectile at roughly Mach 7 at a range of over 100 miles, and major defense contractors are developing a wide range of EMR systems for military applications from naval surface fire support to missile defense. The Cipher Brief talked with Scott Forney, President of the Electromagnetic Systems Group at General Atomics to find out just how close this revolutionary technology is to practical application.

The Cipher Brief: What new advantages does the Blitzer Electromagnetic Railgun system provide for modern warfare, and what role has General Atomics-Electromagnetic Systems Group (GA-EMS) played in the development of this technology writ large?

Scott Forney: Let me tell a story that gives a picture of where we are today. General Atomics has been in the pulse power business for so many applications over the last 50 years that we had to get used to moving around and controlling thousands of kilowatts of energy in split seconds. So, in the 1990s, we started working on new motor technology, which ended up being the catapult for new aircraft carriers called EMALS – Electromagnetic Aircraft Launch System – and in developing that technology we realized that the advent of the semiconductor and the shrinking packages for these electronics had become incredibly cost-effective. That’s when GA really started looking hard at what can we do for a modern-era railgun system.

Our first introduction to the railgun technology came in the 1980s when GA-EMS worked on the Reagan-Era “Star Wars” program, but at that time, if you wanted a pulsed power system, it would be the size of a Costco warehouse. However, over the last eight years, we’ve shrunk the footprint for equivalent energy output by a factor of eight. Now, this power system is no longer something that you need to fit into a Costco warehouse, it’s something that you can integrate into a naval vessel or carry on transportable trucks for the Army. That changed everything, because what was an interesting science experiment a decade ago is a viable system today. This was made possible by downscaling the microelectronics and the semiconductors used in the system, as well as building very small and reliable capacitors, which GA-EMS is probably the world leader in.

On to the electromagnetic railgun, the system basically pumps millions of amperes into two rails, which are separated by non-conducting ceramic material. In order to launch a hybrid missile – many people call it a projectile – electrically, you guide the projectile via riders called sabots. Once you have that you basically short the two rails in the railgun, and the current flowing through the armature – the conductive material connecting the two rails – is what accelerates that hybrid missile to 5,000 miles per hour in a fraction of a second, while the armature flies a couple hundred meters in the air and falls down. This technology – shaping the armature into the railgun and developing a railgun that allows you to repeatedly fire a hybrid missile out – all of that was developed in the last decade to show that we could get a lot more launches out. The result today is something that you can count on for repeatability. Now, based on the testing we’ve done at General Atomics, we’ve done about 160 launches and we don’t see any wear in the railgun.

Finally, the last step in this whole process is a missile that can handle the incredible environment of a railgun. You’re shooting that missile out so fast, and at such a high rate of acceleration, that you have very high G-force loads, huge amounts of acceleration that all the electronics, and batteries, and control systems have to withstand. Therefore, it was very important to get the microelectronics hardy enough to survive that environment. If you can get them to do that repeatedly using commercial-like technology, suddenly you have a very inexpensive round, and indeed that’s what General Atomics has done. We started developing our own hybrid missile in 2012, and we now have a missile with electronic systems that can survive this very intense environment of high G-forces, high temperatures, and a very strong electromagnetic field. By building this with technology that is readily available today you get a system that is two orders of magnitude less expensive than today’s missiles. Thus, when you start thinking about the adversary being able to launch very inexpensive missiles at the United States and our allies, possibly in swarms, we will soon be able to respond with $25,000 hybrid missiles from a railgun rather than multimillion-dollar conventional missiles.

This is the big change, and it’s why General Atomics has invested so much of its own internal money to ensure that we could make this a reality. Indeed, this year is our big test year. We are now testing at the 10-megajoule scale, which we think is the sweet spot for both Army and Navy applications; we now have our fifth-generation pulsed power system just about complete; we have our third-generation railgun built; we actually have a new mounting system that allows us to elevate and azimuth the gun to go after targets, and we’ve tested a radar system. We are very excited about this technology, and I think it is going to revolutionize our warfighters’ capability. For once we’ll have a truly low-cost answer to any missile system out there. That is a huge deal.

TCB: Could you go through that system, the challenges you’ve had, and how it differs from the project that you’re working on for the Navy?

SF: To separate the two, we’ve developed a large 32-megajoule scale railgun for the Navy, which can reach about 125 miles of accurate range. We’ve also developed three generations of pulsed power in support of the Navy. You have two pieces of this technology. First, as we’ve covered, it’s cost-effective, but it also has to be something where you can do burst rounds to take on swarms of targets, and you have to have pinpoint accuracy. We have been able to achieve all of this and the government is currently checking our analysis independently. We’re also creating a pseudo cruise missile of our own later this year so that we can engage it dynamically in real time, which will be the end of the test program that we’re still funding this year. The biggest challenge of all this, to be candid, was how to accurately control the projectile, because we’ve inverted the traditional equation. With every current missile system, you start off slow and by the boost phase you go faster and faster. By the time you get to target that’s where you’re at the speed you need for the intercept. With a railgun, we’re up to speed the second we leave the barrel, and we hold that speed for a great deal of time so it is a very hard thing to calculate the guidance and navigation control systems for.

Over time, we developed that control system but one of the biggest remaining problems was that all this navigation is occurring in a hypersonic environment. To help solve that problem, we bought a boutique engineering firm called Miltec last year that focuses on hypersonic weapons systems, and this gave us the final piece of the puzzle. Without question, developing a projectile that could survive this kind of harsh environment was the most difficult part of the project and that work is completely internally funded. We decided to go that way because we wanted to integrate all the technology instead of being teamed with some of our competitors. This was a risky move and it cost us more than $50 million but we decided that was the fastest way to be successful.

TCB: Let’s talk about the land-based Blitzer system. Can you walk me through how that will work?

SF: As I said, one of the biggest problems with the railgun for missile defense was achieving pinpoint accuracy at such high speed. So instead of trying to hit incoming missiles directly with our hybrid missile, we have packed the front end of our projectile with tungsten impactors. Those tungsten impactors are very dense, and when they end up impacting with an incoming target, you can think of it as a tungsten shield. It is essentially a tungsten shotgun shell at the tip of the projectile, which is very lethal if you can get it in the way of whatever you’re shooting at.

TCB: How about the naval system?

SF: No difference actually. The only difference is we had to develop the system so it was truly transportable. That caused us to really shrink the system down. In the last three years, we’ve actually been able to double the energy density, which is a very big deal. Getting it down to that size allowed us to get it on HEMTTs (Heavy Expandable Mobile Tactical Truck) for the Army – if they choose to use HEMTTs – and it also gives us the option to deliver a portable railgun system that can fit on something like the Littoral Combat Ship.

TCB: It’s interesting that you bring up power density because this has been one of the major criticisms of the railgun, that its power needs are so great a ship would need to stop and divert all power in order to charge and fire the weapon. Is this true?

SF: Not true. I know there are many who think that’s what the design would have to be, because you need to charge the capacitors to fire and therefore you would need a huge integrated electric propulsion or power system to charge those capacitors. But one expertise of General Atomics, specifically the Electromagnetic Systems group, is that we have developed very advanced lithium-ion battery systems. The Navy had a big problem back around 2007 with the Advanced Swimmer Delivery System, in which the lithium ion batteries caught on fire and they couldn’t put it out for several days. That’s because lithium ion is so energy dense that, if a fire occurs, it is very difficult to put out, and you need thousands upon thousands of these cells to operate a railgun.

General Atomics has, for years, been investing in ways to make those batteries safe. In essence, we found a way to control that thermal runaway. Based on this technology, our idea at GA-EMS is that we will charge up these batteries, and then we can release one shot at a time out of the batteries into the capacitors very quickly. With our unique system, if somebody says that they want 40 rounds stored, we can electrically store 40 rounds in the batteries and then charge up those capacitors every time we shoot the railgun. Meanwhile, over time you can get a trickle charge as you run the motor, just like in a car. So instead of needing tens of megawatts of power, we need hundreds of kilowatts and that’s it.

TCB: Speaking about the timeframe then, if you had to make a guess, when do you think the first Blitzer railgun might become operational?

SF: So, our test program will drive that answer, and our plan is to demonstrate the feasibility of shooting down a moving round – that’s the pseudo cruise missile that we’re developing – by Christmas. Once that happens, I think we would be in a position to demonstrate our development system by the end of this year and move on to a tactical system. At the end of the day, we could be fielded within three years.

TCB: Railgun technology has been around for a long time and the theoretical proposals for its use vary from orbital launch to igniting fusion reactions. For you, what is the most exciting aspect of this technology, and will GA pursue some of these longer term moonshot ideas?

SF: That’s what the company has been built on, so naturally we’re interested in what comes next. There are some technologies that we’re working on, which I’m not able to talk about today. However, we have been asked twice by NASA if we could use an electromagnetic launch system to launch satellites or even payloads the size of a space shuttle. So we’ve done designs which show that yes, this is very feasible to do. And we are also in the nanosatellite business, we’re the only provider of satellites to the U.S. Army today, and we’re looking at low-cost ways to get those satellites into orbit. I know everyone’s looking at what Elon Musk is doing at SpaceX in terms of lowering launch costs but, when you think about it, it’s not a stretch to say we could use electromagnetic technology to launch these satellites. So we’re evaluating what that path could look like, and I can say that we have been studying several options to launch satellites and similar-looking vehicles into space. At the end of the day, we’re not trying to drive out the larger missile systems, we’re just trying to give the Army and the Navy more options for layered defense so that you don’t have to use a $10 million missile when you could use a $25,000 railgun projectile.

Electromagnetic Railgun (EMR) has attracted new interest this year as the Office of Naval Research (ONR) continues to test its prototype 32-megajoule railgun system, which can launch a projectile at roughly Mach 7 at a range of over 100 miles. In support of that demand, contractors from across the defense industry are working to finalize a wide range of EMR systems for military applications from naval surface fire support to missile defense. The Cipher Brief spoke with John Finkenaur, Director of Advanced Technology Programs at Raytheon’s Integrated Defense Systems business to discover just how revolutionary this new technology is, and how close it is to completion.

The Cipher Brief: Can you tell me a bit about the electromagnetic railgun and how you think this technology will shape modern warfare?

John Finkenaur: There are a number of things about the railgun that are unique to prior weapons systems. First off, it uses electromagnetic energy to launch a projectile, which therefore means that there is no explosive charge required. On a ship for instance, you can therefore store more rounds in the belly of the ship than you could with conventional munitions and, of course, it’s much safer to store. Given the way that the system operates, you can also scale the firing velocity of the projectile just by how much of the system you charge up. Ultimately what powers the railgun is these large pulse power modules, which are comprised of a number of energy storage components. These modules store the energy needed for each shot and, depending on the kind of velocity you need, the distance, etc., you can charge up either a segment of the system or charge up the whole system. So the railgun is very unique in that regard. The weapon can also be used for naval surface fire support where you’re having to launch hundreds of nautical miles downrange, it can be used for shorter-range engagements, and anti-missile defenses – for instance shooting down anti-ship ballistic missiles. In addition, since the size of railgun-fired projectiles is much smaller than current missiles, your magazine can be much deeper, and eventually, we should be able to achieve a high rate of fire – one round every few seconds. Finally, the railgun can fit a number of different functions simultaneously, firing one salvo for surface fire support, the next for missile defense, and the next for close engagement, etc.

TCB: What role does Raytheon play in developing this technology?

JF: We are involved in providing the pulse power infrastructure – the pulse-forming network – that is used to ultimately fire the projectile. We are also involved in the projectile itself, we’ve helped the government with integration – how you would actually integrate the railgun into a naval ship- or land-based installation – and we’ve also supported the government in some live-fire testing of the railgun. Finally, we’ve provided radars to actually track these projectiles, which are traveling many kilometers per second down the track.

TCB: Can you describe a little bit more about the pulse power system that Raytheon has developed?

JF: In order to launch the railgun projectile, you need to have very high pulse power input, which is generated by these pulse power modules, and it can take hundreds of these pulse power modules to generate one pulse. Feeding these modules is some sort of energy storage device. There is a ship out there called the Zumwalt, for instance, which has all the energy storage that you might need onboard to feed the railgun, but you don’t have this on most other ships. On other ships, you would need as large an energy storage magazine, if you will, as you do the pulse power subsystem in order to launch the projectile. And the way this whole thing works is, again, the energy storage magazine stores up enough energy for a certain number of shots, and then every shot bleeds off some amount of energy with a short recharge time between shots. But, on a ship like the Zumwalt you wouldn’t need that secondary energy storage infrastructure, just the pulse power modules to deliver the current to the rails.

TCB: In terms of the power that you’re talking about to fire one shot, how much is that? And how does the need to pulse that amount power into the weapon in such a short timeframe (split second) affect your thinking with this technology?

JF: Yeah, you’re talking about tens of megawatts of power, which is very large. And of course, usually this power need is measured in megajoules, which measures watts used in a certain time period, and that number is used to denote how powerful the particular railgun system is. So the power needs can really change depending on how far or how fast you want to launch the projectile.

TCB: And your focus has really been to make that operational, to create a system that can provide that kind of split-second power?

JF: Yeah, well technically the biggest challenge was trying to get the barrel right. When you look at the Office of Naval Research (ONR) video test-firing a 32-megajoule railgun, when the projectile gets launched there are a lot of gases expelled and the air begins to burn up around the barrel. The projectile itself rides on a sabot, which is a carrier that glides it along the rails, and as that shoots out and pushes gases out, there’s a lot of wear and tear on the barrel. Now they’ve put a lot of effort into improving the barrel, which has really come a long way with thousands of shots per barrel. But when they first started firing these systems you would fire one time and then have to completely rebuild the barrel. The other major part is the pulse power, and it’s always a challenge to release that much energy at one time. Just getting to the point where you can fire once, and have all these pulse power modules working together in concert, is a real challenge. Then, once you get to the point where it works once, you want it to work many many times, and get it to the point where you can fire a round every several seconds.

Those are the challenges and we’re getting a lot closer. They’ve got a new test range set up at the Naval Research Support Facility at Dahlgren, Virginia, where they’re actually starting to do full-scale live-fire shots, ramping up to full power. It’s still an incremental process but we’re moving forward. And I think the biggest challenge to successful deployment is getting the system to perform at a high rep rate, where we can fire several shots per minute reliably. There are also just so many components to this system. The pulse power system, for instance, is made up of hundreds of modules, each one of which has to be individually controlled so we have to be very precise at every stage.

TCB: How long do you think it will take before an electromagnetic railgun system becomes operational?

JF: I could see a smaller scale railgun becoming operational in the next five years or so. Getting a full-powered railgun – i.e. 32-megajoule ship-mounted system – up and running will probably take maybe 10 years or so. But we could certainly see a small-scale railgun operational sooner than that, perhaps even a land-based system. Actually a land-based railgun could probably be operational within the next five years because you don’t have the challenge of making the system seaworthy. The technology is certainly there and you could definitely see a land-based railgun operational in five years, and a sea-based system within 10.

TCB: What gets you most excited about this project?

JF: For me, personally, it’s very cool to see an idea that you put down on a white paper several years ago coming to fruition. To see that white paper evolve into real hardware and things that are firing and shooting projectiles is pretty cool. It’s not too often that you get to see the whole evolution of a program like that. We actually have a pictorial history of our involvement in the program going from ideas on paper to wooden boxes built to the size of the actual components to check for mechanical spacing, then of course we took those wooden boxes out and actually made the real modules, put those in containers containing dozens of modules, and actually shipped them out to the government. And then finally, it has been great to see the interest and awareness for this technology grow.

TCB: Last thoughts?

JF: Really, the most useful and interesting thing about the railgun is its scalability, and the fact that it’s so modular; you can really shape the technology to fit so many uses from smaller systems, to something that can shoot over 100 nautical miles, to a something that could even launch a payload into space.

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