Tuesday, December 27, 2016

The Hard Math of Hypersonic

As much as I like to emphasize the important but much maligned liberal arts side of this line of work, I have to give a nod to our engineering minded; the math matters. As such, and be kind, but let's exercise that side of the brain today.

Be warned; there will be math.

As the designers of the Long Lance torpedo and its victims will tell you - the engineering matters. Speed. Distance. Rigorous, operationally realistic testing. It all matters. When war comes, they speak.

The numbers - both quantity and quality - are what often at sea define the odds when the shooting starts. It predestines nothing; in Tamarian I believe it goes, "The Spanish Armada in the Channel" or somesuch - but it must be the entering argument. Once you establish that baseline, then you can talk about tactics, leadership and all that liberal arts stuff.

Remember; the Comanche had the best light cavalry in the world; the Germans had the best tanks; the Japanese had the best torpedoes; the French had the best DFAC ... so ... having the best isn't everything, but it is preferred.

In that light, let's look at the most deadly offensive weapon in Anti-Surface Warfare (ASUW). Just in time for Christmas, this little present was slipped under the tree;
Two aging Russian Navy battlecruisers will be outfitted with the anti-ship version of the world's first hypersonic missile, the 3K-22, which carries Zircon (or Tsirkon) 3M22 hypersonic warheads. This hypersonic missile will also arm Russian ballistic missile submarines.

With a claimed speed of Mach 5 or 6,200 km/h, the 3K-22 has a range of 450 kilometers. The weight of the 3M22 Zircon warhead remains unknown but will likely be heavier than the 200 kg warhead on India's BrahMos supersonic cruise missile. 
It's widely believed BrahMos II is the export version of the 3M22 Zircon. BrahMos II, which will have a speed of Mach 7 (8,600 km/h), will be the world's fastest cruise missile when it enters service with the Indian Armed Forces some eight years from now.
Production of the 3M22 Zircon is expected to begin in 2017. Tests of this warhead began last March.
Yes my friends, over the last couple of decades as our best and brightest spent a lot of real capital - not to mention mountains of political and reputational capital - on one ship to counter Boston Whalers and another designed with around guns that can't afford the rounds it shoots - other navies were focused on weapons designed primarily to keep the premier global power from operating in THEIR seas, i.e. sinking the US Navy.

We made the decision that we could push to the right and accept the risk of not being able to do the same. In the post-Cold War era, we got a bit spoiled and rested on our temporary supremacy at sea. As a result, most of our primary surface warships built since the fall of the Soviet Union - the DDG-51 Class - don't - and more importantly can't - even carry Anti-Ship Cruise Missiles (ASCM), let's check in on what we have in the near term inside our lifelines, and what may be peaking it's nose over the horizon. 

As a companion piece to what I ran last month at USNIBlog, let's look at a couple of things;

- What we have.
- What they have.

When you can you see it?

How long until a weapon is ready to engage?

At what distance will your weapon intercept it?


...or perhaps this?

With those ASCM in the green, like we have seen off Yemen this year, we can handle that. Those in the Yellow? We've been thinking about that challenge since the end of the Cold War.  

Those in the Red?

Well, do the math and it doesn't take long to realize that the only effective kinetic counter to hypersonic once it makes it to a few minutes from impact needs to be, yes, the speed of light; lasers. Lasers are limited to line of sight, so that gives us the visual horizon of a warship.

I warned you there would be math. Let's use round numbers for a point to argue from; if both the incoming weapon and sensor are 30' above the water, that gives you a visual horizon to detect of 12.9-nm. For a missile going Mach 3, that gives you about 21 seconds to impact. 

Again, follow the questions between the spreadsheet and the video above.

That is for a Mach-3 ASCM. Now do the math for a Mach-5. A Mach-7.

It does focus the mind a bit, yes?

For some, this brings up the old saw, "Shoot the archer, not the arrow." OK; shoot it with what?

I actually like the archer analogy for a couple of reasons. Here's one way that goes a little deeper. 

Let's go back to the "archer." In the late Middle-Ages, the English/Welsh Longbowmen were the terror of Europe. They were fast, agile, and could eliminate the flower of European nobility hundreds of yards before that nobility, with their shining, exquisite armor and expensive lances, maces, swords, and battle-axes could be brought to bear.

Longbowmen were also very vulnerable, as they were lightly armed. The only way to eliminate them from the field was through a surprise cavalry attack from the flank or by your own archers who had the range, will, and numbers to move them off the field.

We have yet to see a Battle of Crécy at sea to really show the power of the ASCM. From the coast of Sinai, to the Falkland Islands, to the Persian Gulf, we have seen little demonstrations over the last couple of decades, that is about it. 

We have been warned.

Note I didn't include the recent US Navy swatting down the relatively primitive ASCM used off Yemen. That generation of ASCM really is no match for our DDG as long as everything works. That exchange ended as it should - but we should not think we have the modern problem solved.

In time, it was only the invention of the firearm that ended the Longbowman's tenure. That took awhile, as will our response to modern ASCM.

There is a larger question here, and it has to do with a dominate power's complacency. We mostly talk about defense - but what are we doing about offence? Why is it the world's premier naval power has some of the slowest and shortest range ASCM?

Does that fact give you pause? It should. Look at what we are, replacing Harpoon with, perhaps, LRASM and NSM. Are they even supersonic? No. Do they challenge modern defenses? On paper, not really if you discount any electronic fairy dust.

In some ways, we are just building the best, most high-tech pre-Dreadnoughts in an era when Dreadnoughts are growing in number.

NB: all speeds used here are from open source material. You, or I, may have different speeds in mind - but keep all that to yourself. This is just to demonstrate a point, not be military pedantic or to forget that we are blogg'n in the Red, not Green. An errata as well; "NATO Strike Missile" should be "Naval Strike Missile." My bust, I had NATO on the brain.

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