Dr. Mark Lewis Talks About the Coming Hypersonic Cruise Missile Threat

08/15/2018
By Second Line of Defense

Our interview with Dr. Mark Lewis first published on April 2, 2013, highlighted the key dimensions of the hypersonic missile threat which has only recently become more visible in the public debate.

That interview as published follows:

We continued our discussion with Mark Lewis, former Chief Scientist of the USAF and currently head of the Institute for Defense Analysis’s Science and Technology Policy Institute.

Dr. Lewis is a leading expert on hypersonics.

Earlier, we discussed hypersonics with Dr. Lewis, but in this interview we focused on one low hanging fruit which could be available sooner rather than later, the hypersonic cruise missile.

In the context of rolling out a F-35 fleet, the hypersonic cruise missile can be a key part of an evolving approach.

In effect, hypersonic cruise missiles are part of what one might call an S3 or S Cubed dynamic for 21stcentury expeditionary technologies.

Sensors, combined with Stealth combined with Speed can provide a new paradigm for shaping the Pacific force necessary for the US in working in the Pacific.

The development of a hypersonic cruise missile would clearly be a game changer, especially as it would come in the context of rolling out a deployed fleet of F-35s, both allied and American, in the Pacific.

The Chinese DF-21 would rapidly become a distant memory.  The discussion in the Western literature of the DF-21 does reveal a serious gap.

There is no real discussion of the interaction of technology on strategy by the United States and its allies.

Or to put another face on the question, the Chinese put on the table that they have developed a technology – in this case the DF-21, which actually has not been tested against maneuvering capabilities like ships – and worldwide there are stories about the impact on the US and its allies.

But there simply is no look at what the US and its allies are building to shape a different strategic environment as well.

Artist conception of X-51 hypersonic cruise missile. Adding speed to the sensor and stealth enterprise is an essential element. Credit Drawing; USAF

SLD: How important is this missing technological consideration in shaping Western strategies?

Mark Lewis:  Let me step back with a historical example that I always like to use to illustrate the problem of the missing technological analysis.

When I was in the Pentagon, we would talk a lot about avoiding technological surprise, sometimes a bit too much. There are certainly reasons to be concerned regarding future peer adversaries.

But the surprises that I’m most concerned about are the surprises based on simply underestimating a potential adversary.  Meaning that we assume we have absolute superiority, and that others can’t make advances that in fact they’ve already made, or are poised to make.

I’ll give you my very favorite story along those lines; it was actually from the early U.S. Navy. The United States decided to build a fleet of ships in the early1790’s; they did their analysis, they looked at navies around the world, they looked at Great Britian with its array of everything from small cruisers to ships-of-the-line.

And the Americans shaped their own model of operations by building a fleet of frigates, the first six Frigates in the U.S. Navy.

They figured out that they didn’t have the resources to go really large; they wanted something that was fast, flexible, but also powerful. The United States didn’t have experience in building such ships. Essentially they built a fleet that was invented from scratch.

They had ideas of what the ships were supposed to look like; they had ideas of how they should operate, but they didn’t have preconceived notions of how they should be designed.

The fleet of ships that they built included the USS Constitution, the President, the Constellation, and what’s interesting about it is that, by not having those preconceived notions, I think it gave them a significant advantage. They were able to step back and reinvent many aspects of those ships.

The Naval architect who is primarily responsible for designing the Constitution and her sister ships, Joshua Humphreys, wanted to build these ships larger, but he knew that when ships got too large, they tended to sag a little bit and that’s because, as Humphreys understood, the contemporary structural designs weren’t quite right.

So, he redesigned the structure of his ships to have diagonal braces that would support higher loads.  Those American ships could be built bigger, and therefore thad could have more guns than comparable British vessels.

The Americans did research in hydrodynamics, they understood what the hull should look like.

They looked at materials, and assessed the various woods that were available and they realized that there were really strong woods available in the swamps in North Carolina and South Carolina and they harvested those woods to build these Frigates.

Now fast-forward to the War of 1812, to the first major engagement between a British Frigate and one of the American Frigates.  The British frigate, HMS Guerriere, was actually newer than the Consitution; when itw engaged the USS Constitution it did so with what the British would discover was faulty intelligence and erroneous assumptions.

The British knew the American ships were big so they figured they were going to be slow, lumbering behemoths.  They thought that they were overweight, so they thought they would be terrible handling ships.

They knew the ships had been built in Boston and Philadelphia, so they figured they were built with the woods from the northern part of the country, including firs and pines, which are not structurally sound.

If you imagine the British commander, he saw the Amerian frigate; he probably thought it was going to be easy prey.  And so, he began a rippling broadside, and probably the first thing he noticed was that this American ship was sailing faster than it was supposed to be sailing.

And then, the next thing he noticed was that instead of splintering the wood on the sides of the ship, his cannonballs were actually bouncing off and of course, the Constitution got the name Old Ironsides because of that.

And then the Constitution came cruising up alongside the Carrier and unleashed a single broadside.  And basically, the battle was over in 15 minutes, and the rest was mostly cleanup operation.

And the irony is that the British probably should’ve known better, but they were arrogant.  The U.S. was essentially a third-world nation, how could the US possibly field this technology when the British were the masters of the oceans.  How could we possibly beat them?  And yet, the US did.

And every subsequent engagement between the British Navy and the U.S. Navy early in the War of 1812 resulted in an American victory, such that the British Admiralty issued an order to avoid single-ship engagements.  I mean, this would be like the U.S. Air Force telling all of its F-22 pilots if you see an Iranian flight air, run away.

That’s basically what the British Admiralty did.

It wasn’t until the battle of the Chesapeake and the Shannon sometime later in the war that the British restored their national honor.

Technology shapes strategy and strategy drives the need for technologies, but technological surprise is a key fact of competitive life.

I think this the challenge that we have, and especially in this 21st century where information is so readily available.  This last fact means that an adversary or a potential adversary or even a competitor has enhanced capabilities for technological surprise, by learning from our examples and mistakes, and perhaps by taking a clean sheet approach to design.

I think hypersonics really does fall into that category. 

This is a technology that the United States has been working on really the 1940’s.  The first time we flew something at a hypersonic speed – beyond five times the speed of sound – was the WAC bumper flights right after World War II.

We basically put a sounding rocket on top of a V2 missile.  But those were certainly hypersonic flights.  We’ve understood hypersonic aerodynamics since the 1950s, every spacecraft we’ve brought back from space has been traveling at hypersonic speeds on reentry.

The papers are out there, the theory is out there, and the computer codes are out there.

Most recently, our interest in this field has been in things that breathe air, meaning that they are powered by engines that operate off of oxygen that’s gathered from the atmosphere.

But even there, the concepts have been around for many, many years.  The original papers that were written in this field date from the late 1950s; they were done at the old National Advisory Committee on Aerodynamics, the precursor to NASA.

And so, hypersonic flight is not a new idea; we had even planned on doing tests of high-speed hypersonic engines during the days of the X-15 program in the 1960’s, but the program was cancelled before powered engines could be flown.

There is this rich body of literature out there from which almost anyone could pick and choose and see what worked and see what didn’t work.

I really think we’re kidding ourselves if we don’t think that other folks understand the impact of some of these technologies on the evolution of warfighting and are looking at the dramatic strategic consequences of deploying hypersonic technologies.

SLD: Let us look at the applications of hypersonic cruise missiles to the Pacific.

Clearly, a significant Chinese hypersonic cruise missile capability deployed in advance of American capabilities would be dramatic in its effects.  The United States struggles with the tyranny of distance to deploy its forces in the Pacific and to forward deploy with allies.

Mark Lewis: I’m going to expose my biases here. Distance only has tyranny if you’re clanking along at 30 knots.  If I’m flying at mach 2, mach 3, mach 5, mach 6, I don’t think distance is such a tyranny any longer.  And I think that’s what speed and range, by the way, in combination brings to the equation.

You’re exactly right that as we go into the 21st century we can’t forget about the role that technology will play as a force multiplier.  But also, the role that technology brings to each of the capabilities that the services bring to the fight.

Again, when I was in the Pentagon, I used to ofer my explanation for the very existence in the Air Force.  Why is there a separate Air Force?  Well, it’s because of the special technology, and the practitioners of that technology, that are unique in the Air Force mission.

Put another way, why was it important that the Air Force not remain the Army Air Corps?

Because the technology was so significant and designed to such a different paradigm that it required a separate service.

I don’t think we can separate that technology from 21st century warfare.  We hear a lot about boots on the ground, we hear a lot about getting the soldier into the fight.  I certainly don’t think that will be true in the Pacific theater.

Airpower will be the determining factor. Certainly, I think our adversaries understand that.

They realize that if they can’t meet us in numbers, then they can meet us in technology and they can meet us in engineered solutions that specifically address capabilities that we have.

SLD: In effect, hypersonic cruise missiles are part of what one might call an S3 or S Cubed dynamic for 21st century expeditionary technologies.

Sensors, combined with Stealth combined with Speed can provide a new paradigm for shaping the Pacific force necessary for the US in working in the Pacific.

Does that make sense to you?

Mark Lewis: Absolutely.  I love the concept of S-Cubed.

It makes a great deal of sense in describing the inherent or emergent paradigm.  Certainly, we’ve enjoyed a tremendous advantage with stealth, we know that the stealth advantage is changing, other people are developing the technology, which is why it behooves us to look even further.

I’d say very simply if I can  no longer be invisible, what’s the next step?

And the next step is let them see me and not be able to capture me.  Couple that with exquisite sensor technology, and I think you absolutely have a winning combination.

SLD: We could look at the hypersonic cruise missile program as the equivalent to the Polaris program directed by Admiral Rayburn.  In the late 1950s, Admiral Rayburn directed Polaris program where American political will identified that the technology was essential for American national security.

At the highest political levels, it was decided that we really have to commit resources to bring one of the elements of strategic deterrence into being. Is the hypersonic cruise missile such a case?

Mark Lewis: I think that it is.  I would also draw analogies to the early work that eventually led to the development of ICBMs.  The initial resistance of the bomber community to ICBMs was significant.  General Le May originally referred to them as “firecrackers.”  But to his credit and that of the rest of the USAF leadership, they marshalled the resources and built the ICBM fleet.

I think hypersonic flight requires a very, very similar change in mindset.

The fact that I can flight at such speeds means that I can reach in quickly and that I can reach far. Hypersonic systems would give us the ability to marry surgical precision with rapidity of action.

And would also provide a measure of invulnerability in the face of enemy defenses as well.

Rather than thinking of it as a silver bullet but part of an S Cubed force, hypersonic speed could enable the forward deployed F-35 stealth fleet to guide lethality to a broad variety of targets.

SLD: And it is not just about the delivery vehicle, but innovation in the types of warheads, which could be delivered by such, a missile is crucial as well.  Don’t you want to marry the missile with warheads which have the ability to get inside the electronics, the fire controls, the signals, the sensors of your opponent flying at hypersonic speeds to fly the sites, shut down the radars, lights out?

Mark Lewis: The ability of a hypersonic flyer to reach in quickly and do things, shut things down, shut things off, I think that’s a wonderful combination. 

That’s a winning combination. Imagine that a potential adversary knows that you can be there really, really quickly and you can get in really, really deep, and you can do it from platforms that they can’t reach, well I can’t imagine why we wouldn’t want that capability!

SLD: When we talk about putting resources up against a priority task, it is important to highlight it is really about concentrating investments.  We have been living off of old weapons technologies for a long time, with the F-22 flying largely with yesterday’s weapons technologies.

And a clear advantage of the F-35 will be the ability to leverage global investments in the evolution of new weapons technologies.

So if MBDA builds a 21st century AMRAAM, rather than investing in the US alternative, the US could choose to leverage other F-35 partners investments and concentrate on key priority weapons programs, such as hypersonic cruise missiles.  How important is prioritization to getting the job done?

Mark Lewis:  I think you hit upon an absolutely key point, which is that we’ve got connections and ties with allies who are using the same sort of systems, we can leverage their investments, leverage their knowledge, let them build on our knowledge, and produce systems that are of use to all of us.

It makes perfect sense.

But let me stand back and discuss the question of cost.  I often here that hypersonics will be expensive.  We don’t know what it’s going to cost. It’ll probably be more expensive to build a hypersonic cruise missile than a subsonic cruise missile.

But how much more?

I don’t know.

We won’t know for certain until we develop the technology further.

But more importantly, if a high-speed system can do the job of ten or 20 low-speed systems, well, doesn’t it make sense to invest in that, perhaps, higher unit cost system, if it’s ultimately more effective?

Let us consider the case of the original strike against Bin Laden. You can imagine the bean counters saying boy, if we build a hypersonic weapon, that would cost a whole lot of money.

But what if we’d had that hypersonic weapon back when we launched our cruise missile attack on his compound? we might have gotten there before the man left and then everything that transpired afterwards, including 9/11 would not have occurred.

What would that have been worth?

It’s hard for me to put a cost on the ability to react quickly and effectively and deeply and prevent bad things to happen.

The issue really is not the total amount of our investment in science and technology; it is about investing wisely.  Hypersonics is a great example.  If you actually look at the total amount of money we’re investing in it, it’s actually a pretty good portfolio.  Between all the various projects we’ve got, X-51 and HTV2 and AHW, it’s an alphabet soup of programs.

But honestly, it is too uncoordinated: not well coordinated between the services, certainly not well coordinated between the defense laboratories and DARPA as effectively as it ought to be.  NASA had an investment but that’s been an on again/off again commitment.

So our success in hypersonics is about more than simply developing technology, it’s about getting those investments focused on something that’s useful and practical and operational, and I think that’s actually a bigger challenge than getting money per se.

SLD: And does not a hypersonic missile woven into a fleet of evolving capabilities significantly enhance the viability of the force and its lethality.

For example, there is much literature on how the aircraft carrier has seen its day.  Imagine the F-35Bs and Cs provide the forward punch to the sea force and identifying forward targets along with robotic elements deployed in the water, under the water and in the, air and guiding a set of new weapons on the F-18s based on the carriers, including a hypersonic cruise missile.  What is there not to like about a maneuvering ship with a variable geometry strike force onboard?

Mark Lewis: I agree.  And I’ll give you another example.

After the first flight of X-51, a reporter for Wired Magazine wrote an article about it.  Recall that the X-51 was our experimental hypersonic vehicle that was carried aloft under the wing of a B-52.

And at the end of the article, he waxed a bit poetic about how wonderful it was to see a 50-year-old B52 as the carrier aircraft launching the X-51. He pointed out that if this became an operational system, it would reinvigorate and completely change the mission for something like the B52.

I think a very similar analogy applies to your carrier example.

An old asset now becomes a reinvigorated asset that allows us to deploy and launch quickly and reach deeply, and to do it without susceptibility.

But it is really most effective in the context of what you called S Cubed, namely, sensors, stealth and speed. Speed is not a stand-alone silver bullet.

By the way, some people can get hung up about the definition of hypersonics.  We usually agree that hypersonic means in the neighborhood of about mach 5, five times the speed of sound.

The reality is if we had a cruise missile that “only” went mach 4.5, that would still be pretty darn good.  More importantly, what I’m interested in is the effect that I want to enable: I want to be able to reach in quickly, I want to be able to strike surgically, I want to be able to puncture right through an adversary’s air defense system.

Alternatively, I might go through it or go above it or go around it.  And that to me is really what we’re talking about when we discuss hypersonics.

It’s the capability that we’re bringing to the fight.