Avangard: A Boost-Guide Primer

James Acton 0:02

Longer and thing are not that technical, Jeffrey.

Aaron Stein 0:08

You are listening to the Arms Control Podcast, the leading podcast on arms control, nonproliferation and disarmament. My name is Aaron Stein. I am the director of the Middle East Program at the Foreign Policy Research Institute.

Jeffrey Lewis 0:21

Yeah, so you no longer have an ocean view. You've traded in for a farmhouse, I've heard.

Aaron 0:40

It's freezing cows, just miles and miles of freezing cows.

Jeffrey 0:44

We have a guest today, though. We have James Acton, who is the co-director of the Nuclear Policy Program at the Carnegie Endowment for International Peace. Hey, James.

James 0:57

Hey, Jeffrey. Thank you for having me. Did I get the title right?

Aaron 1:01

I wasn't really paying attention, so probably. You left that hypersonic wonking guru.

Jeffrey 1:08

You know, James has written a couple of papers about hypersonic weapons that I really think are like kind of the model of sophisticated, technically informed arms control analysis. It kind of harkens back to the good work that people did in the 1960s and in 1970s. And so I couldn't think of a better person to have on if we were going to talk about Russia's Avangard missile, because, hey.

Launch a missile, get a pod.

Aaron 1:35

That's right. And then we tease this out sort of on the podcast last week where we were talking about early shows. And I think, Jeffrey, your contribution to the story is that you and your team geolocated the launch site and got some really cool pictures.

Jeffrey 1:49

Yeah, I mean, it's a modest contribution. I mean, one of the fun things is our, you know, relationship with planet in San Francisco. You know, in theory, it's a picture of the world every day, although it's cloudy a lot. And there was a picture taken just a couple hours before the launch. We were able to use the video that the Russians released to figure out which silo that they launched it out of, which was not a surprise.

It's the silo, I think, that they pretty regularly use for testing. But it was beautiful because there was a lovely blanket of snow. And in that snow, there were vehicle tracks showing clearly that they had driven down and were getting ready for the launch. So that was interesting. That was cool, but I think we're less interested in the going up part and more interested in the coming down.

Aaron 2:37

Yeah, I think for listeners and even for me, I mean, James, if you could sort of fill us in on the details of this missile, because as we were talking off pod, there's a lot of misinformation out there about what the hell this thing is.

James 2:51

Sure. Well, why don't we start by talking about what a boost glide weapon actually is, and then we can zoom down into the specifics of Avangard. I guess that means this is a boost glide weapon. That's right. Probably. I mean, you know, there's actually a huge amount we don't know about this missile.

Jeffrey 3:09

So, you know, I think it makes sense to talk a bit about what gliding weapons are to start with.

James 3:16

So a normal ballistic missile... Is goes in an elliptical trajectory, almost all of which is above the atmosphere. So there's the boost phase while the rocket flies. And then the engine's cut out and the thing just falls under gravity. It'll, you know, a bit like if you just threw a ball hard enough. And it would be an elliptic trajectory that at the very, very end of the trajectory reenters the Earth's atmosphere.

And typically in a ballistic missile, that thing is just unguided when it reenters the atmosphere. In a boost glide weapon, what you're doing is you're trying to re-enter the atmosphere, often at a much more shallow angle than with a traditional ballistic missile. And then your re-entry vehicle is a winged type thing, though the wings actually may look completely different from a plane.

And it can just glide. It's supported aerodynamically and is then in a gliding trajectory. It's a bit like a hang glider, just moving a lot faster. And these things were first conceived of by Ugen Zanger, the Austrian aeronautical engineer in the 1930s. And there's been periodic spouts of interest in trying to build them ever since. But it now looks like we're entering a world with developments in the United States, in Russia, in China, in which these things are actually being realized.

And the claim is that Avangard is one of these boost-collide weapons.

Jeffrey 4:44

So, I mean, conceptually, I often wonder, I mean, why people don't, I mean, maybe people don't pick this analogy because it's misleading in some way. But, I mean, I think of it as like the space shuttle, right? I mean, I know the space shuttle enters orbit, but it wouldn't necessarily have to. Right. You know, you're putting something up with a rocket, but it's going to glide when it comes back down, you know, with the exception the space shuttle is not supposed to explode when it comes back.

James 5:10

Well, I actually think the space shuttle is not even an analogy. It's an example of a glider. In the space shuttle, you're absolutely right. I mean, when this thing reenters the atmosphere, it has some, because of the wings, it has a lift force. And it's gliding for very substantial distances, or used to glide. When it was used, well, the pilots piloted it towards the runway.

And actually, the space shuttle, so we classify gliders according to their lift-to-drag ratio. That's the ratio of the amount of lift force that the wings generate Relative to the drag force that it experiences in the atmosphere. So for the space shuttle, the lift-to-drag ratio was about 1. For the HTV-2, which was a US prototype glider that was flown twice and failed twice on tests, the lift-to-drag ratio was something in excess of 2.

I think the estimate that I came up with was something like 2.4, 2.5. I actually forget what my exact estimate was now. So, you know, a really advanced glider, and there's, I think, a very legitimate question about whether Avangard is in that category of advancement, but a really advanced glider would have that lift-to-drag ratio of something above two.

Jeffrey 6:26

Yeah, so this is why people jokingly called the space shuttle a gliding brick.

James 6:32

Right, because it's...

Jeffrey 6:35

The lift-to-drag ratio is pretty poor. Yeah.

James 6:37

Well, I mean, you know, you say that. Actually, it's by no means easy maintaining a lift to drag ratio of one. And actually, the big challenge here more than anything else is the heat management. You know, we obviously saw that with the shuttle crash on landing. But the prodigious amounts of heat that's generated by these things as they're barreling through the atmosphere, how you manage that heat without it destroying the air structure is the big challenge.

And generally speaking, as the lift to drag ratio goes up, the heat management challenges get higher.

Jeffrey 7:10

I just I just have to make us all feel bad. I was explaining this point today in my class up here at Middlebury. None of my students remember the Columbia disaster because it happened in 2003 and they were all too little to notice.

Aaron 7:25

Well, our last podcast, you made a John Cusack reference, Jeffrey. So at least you're getting in the 2000s.

Jeffrey 7:31

Yeah, I also tried to make a dude wears my car joke went nowhere.

James 7:36

I thought you were about to say you felt bad because you were making jokes about the space shuttle crashing, Jeffrey.

Jeffrey 7:40

Anyway, let's move on.

Aaron 7:43

If I had to jump in here, I mean, because I think what the focus is often is on the speed of reentry. And I think what you're telling us is the speed is secondary more to the slip to drag. Is that correct?

James 7:54

Well, I mean, secondary in terms of what? But look, let's put it this way. The speed at which a glider reenters the atmosphere Is basically going to be the same as the speed on which the missile it's based would re-enter the atmosphere. I mean, let's talk a bit about Avangard. The reporting is that it's launched on an SS-19 intercontinental ballistic missile.

So the speed at which it re-enters the atmosphere is going to be set by the inherent power of that booster, if you like, and by the mass of the re-entry vehicle. So it's going to re-enter at a fairly similar speed To that it would do when it's carrying a normal non-gliding reentry vehicle. What the lift-to-drag ratio is going to set in combination with the speed of reentry is how far that thing is going to travel, how far it's going to glide in the atmosphere.

If you have a high lift-to-drag ratio, you could be gliding for thousands and thousands of kilometers. If you have a lift-to-drag ratio that's not that much better than the normal RV would be, It's basically just a reentry vehicle with a couple of flaps on for steering, it's not going to travel very far. So you should really think about this as a spectrum.

At one end, you basically get RVs with flaps on. At the other end, you get super advanced, ultra long gliding intercontinent things that can glide huge distances. And the question is, where along this spectrum does any given wing reentry vehicle lie?

Jeffrey 9:23

James, you mentioned some uncertainties about the glider on the avant-garde. And I wanted to ask about modeling that. And so do you find that you can approximate the lift-to-drag ratio if you know the shape, or I presume shape and mass, or is that actually pretty variable?

James 9:51

If you really know the shape. You can certainly estimate the lift-to-drag ratio from the shape. And generally, though, it's not just the shape. It's also the angle of attack, the angle at which the nose of this thing travels through the atmosphere. So generally, you know, based on open-source information, you don't know enough information to estimate the lift-to-drag ratio from first principles.

I mean, you look even at a really simple... Glider, like to use another example, the US Advanced Hypersonic Weapon, the AHW, which is basically a cone to first order. There's various second order corrections you might want to make, but it is basically a cone to first order. It's not very hard to estimate the lift to drag ratio of a cone.

The problem is if you don't know what angle of attack it's flying at, you don't get a single answer. So the way that I estimated the lift to drag ratio from the HTV-2 was not a first principles things from its shape. It was there just happened to be enough information from lots of different government sources that you could work out how much this thing was slowing down in the atmosphere.

And that would then give you an estimate of the lift to drag ratio. But I do want to emphasize something you said, because I think this is going to be a good thing to discuss in this podcast, which is there's actually a lot we don't know about Avangard. And it's kind of painted as this super weapon that can Destroy and blow up everything, which in a way is true because it's nuclear armed.

And so that's not all that different from any other nuclear thing. But actually, you know, how sophisticated, how advanced this is, I think there's huge uncertainty about this. And that's something that I really haven't seen reflected in much of the media reporting.

Jeffrey 11:43

And we haven't seen a picture of the glider. Is that correct?

James 11:48

I think that's correct. I mean, you often see both with Russian and Chinese sources pictures of U.S. gliders that the U.S. has released being painted as, you know, Chinese or Russian gliders. But I don't think I've ever seen a credible picture of Avangard.

Jeffrey 12:03

And so what kind of information in attempting to model something like this are you going to be looking for? I mean, I guess you'll want to you'll eventually want a picture so you can know the shape. You want to know what how how far it glided and how much it slowed down.

James 12:15

Right. Well, I mean, that was the stuff that proved the key to modeling HTV-2. There were documents like environmental impact assessments. There were documents like presentations given by DARPA employees. All these documents gave enough information about the speed at various points in trajectory, the time, the altitude, that I could formulate a mathematical model for how quickly this thing was slowing down through the atmosphere.

And that then ultimately left to the lift-to-drag ratio. I just, modeling, as I said earlier, modeling the lift to drag ratio from first principles based on the shape of the glider, that's a really difficult thing, as I say, because it doesn't just depend on shape. It also depends on the angle of attack which this thing is flying through the atmosphere.

But at the moment, you know, I think I would identify kind of three key uncertainties in the performance of the Avant-Garde. And we can maybe go through and discuss them one by one. The first one, as we've already discussed, is the lift to drag ratio. Is this thing basically a ballistic missile with some limited maneuvering capability, or is it a real genuine super long range glider?

Second uncertainty is how much maneuvering capability does it have, particularly in the terminal phase, which matters when you're evading defenses. And third critical uncertainty is how accurate is it. Which determines whether this is only a delivery system for nuclear weapons or whether it can usefully militarily be used for delivering conventional weapons too. And those are the three things that we just don't know based on open source information.

Jeffrey 13:56

So, I mean, I understand that the lift to drag ratio is going to tell us something about how far it can glide and what happens when you bring maneuvering or turning in the model. How does that end up? Complicating things like, is, is the ability, is its maneuverability a function of other things that are in principle knowable, or, or is it some other factor that I'm not thinking of? Well, I mean, clearly they're in principle knowable. I mean, let's talk about the way that a glider turns. I mean, basically it banks rather than you know, if you imagine it's just like a plane banking.

James 14:35

If it twists through the air slightly so one wing is higher than the other wing, then the lift force acting on the glider is no longer directly upwards, but it's pushing the glider to a side. So that kind of maneuvering is useful in the mid-course phase because you might want to avoid overflying certain sensitive areas. But mid-course maneuvering, we're thinking of very, very long radius turns.

The more interesting case is in the end game, as the glider's approaching the target. If you're approaching a point target that has advanced sophisticated missile defenses, one of the claimed advantages of gliders is that they could maneuver extremely quickly to evade the defenses. That's really difficult. I mean, you have to be pulling turns at 10, 20 g plus in order to have perhaps even higher than that in order to avoid sophisticated defenses.

And I'm kind of skeptical that that's the state. I think that's probably far beyond the state of the art with gliders at the moment. But again, you know, we really don't know. So, you know, knowing enough information about the shape of the glider and its performance, you could certainly model this. That's not something that I think I could reasonably hope to do.

Aaron 16:00

I mean, I think on the third one, too, is somewhere I'd like to jump into about how accurate is one of these unknowables, because I think that speaks to something you've written about before, which is the ultimate intent of these types of programs across the three different countries against the US, the Chinese, which I've written about a lot, and then the Russians as well as like in that sort of.

Factors into, A, how long it glides, the range of the glide, and two is ultimately what intent these weapons serve, if they're to be nuclear dual capable or conventional.

James 16:34

Yeah. So, you know, in the U.S. case, for example, all U.S. glider efforts have been focused on the delivery of conventional non-nuclear munitions. As I understand it, there was a discussion within the nuclear posture review about nuclear armed gliders, but that ended up getting axed. So the US at the moment at least is firmly focused on the conventional side.

Russia, by contrast, has historically been focused on the delivery of nuclear warheads as a way of evading US ballistic missile defenses. I mean, I should stop here and say, Jeffrey has said many times, and I have too, it's not as if our current missile defenses can defeat Russian ICBMs anyway. So Russia already has the capability to nuke us with ICBMs.

Gliders are kind of making assurance double sure, I think. Though Russia may be more paranoid about the capability of US ballistic missile defenses than I am. But anyway, I think it appears that this The avant-garde program in its original, original form dates back to post-Reagan Star Wars speech. It was then revived after the Bush administration withdrew from the ABM Treaty in 2002.

And this was very much about the delivery of nuclear warheads through US ballistic missile defenses. The question then becomes, can you also add a non-nuclear warhead on this thing as well? And that depends on accuracy. I mean, if you have an accuracy of, you know, 40, 50 meters, that's totally fine for the delivery of nukes. It's not going to be a very effective non-nuclear weapon with an accuracy of 40, 50 meters.

You really need to get down into just a few meters of accuracy. And that's potentially super challenging. So I think one thing that's notable for me is in Putin's speech, 1st of March, the big speech where he unveiled all of these different new capabilities. There were two gliders that he was talking about. One was the Kinzhal glider, which is a much shorter range, 2,000 kilometers or so, air launch system.

And that, he said, it could deliver both conventional and nuclear weapons. Whereas Avangard, he didn't make the same claim about. There has been some media claims, but Putin himself didn't boast about the dual capability of this system. Now, I'm reluctant to read too much into any one data point. But that may be a weak piece of evidence that avant-garde is only for the delivery of nuclear weapons and not yet conventional weapons.

But, you know, very low confidence assessment.

Jeffrey 19:11

I had a question about accuracy and guidance, because I think when some people hear maneuvering, I think they have the idea that one could maneuver in order to improve accuracy. But it strikes me that that's probably not the case, right? That... I mean, I imagine that a glider, it's going to actually be a bit harder to maintain levels of accuracy that we've seen with ICBMs.

But what, I mean, you're the person who's more likely to know that than I.

James 19:42

Well, I mean, it's true you have to maneuver to enhance accuracy. I mean, in the case of a normal ICBM just with a non-steering RV, the single biggest cause of inaccuracy Is atmospheric conditions at the target, things like wind. I say things like wind is the biggest cause of inaccuracy. So you have to, in something like Pershing 2, for instance, which was essentially a reentry vehicle with flaps, you could enhance the accuracy by steering.

The real problem is what guidance and navigation system are you using over potentially tens and tens of thousands of Tens of thousands of kilometers. And the US has chosen GPS, for instance. The glide times are just too long for inertial guidance, which is this kind of purely self-contained guidance system based on gyroscopes. They're just not going to be accurate given the time and distances over which gliders potentially could fly.

So you'll probably have to resort to some kind of external guidance. GPS is what the US has chosen. GLOSNASS is what the Russians may be using. And that's difficult for other reasons. Ensuring the glider can receive the signal through the sheath of plasma that tends to form is one particular challenge. And then ensuring that the glider can actually take advantage of that to enhance accuracy, that it can control the gliding and maneuvering well enough.

You could put in some kind of terminal homing system, which was what Pershing 2 chose. When you're going at very high Mach numbers and with huge amounts of heat being generated, that is a non-trivial technical problem. So the answer is you have to be able to glide to get it accurate. You have to be able to maneuver, I'm sorry, to get it accurate enough for the delivery of conventional weapons.

But actually making a system that works end-to-end is a real technical challenge.

Jeffrey 21:44

I guess my question is, while I understand the value of fins to maneuver, I guess does gliding cause the reentry vehicle to be so much more subject to factors like wind? Given that you're talking about how hard it is to maneuver in the terminal phase, I guess I'm curious as to whether one is giving up more accuracy to By getting the glide than one, you know, compared to if, for example, you just did little steering fins and basically had a traditional RV.

Aaron 22:22

Just to add on to that, just what I was thinking is if it's having to turn at high Mach numbers, or sorry, at high G to avoid missile defense, could that also impact late stage guidance, you know, that final stage guidance, and therefore you're offsetting from it by trying to defeat missile defense?

James 22:42

I mean, going to Jeffrey, I mean, I guess that's right. That, I mean, I, I mean, I mean, I think we're saying exactly the same thing that the longer this thing glides for the challenge, simple little non physicist words. I mean, longer and thing are not that technical Jeffrey. But you know, the longer this thing glides for the greater, the challenges of having accuracy.

That's good enough for delivering conventional weapons become. I think we are saying the same thing there. And in answer to Aaron's question, I mean, totally. And I think we saw this with, if I remember rightly, the US has deployed systems, sorry, never deployed, but developed something called the Evader reentry vehicle. I think it was the Mark 500, but I could have the number there wrong.

That had a maneuvering capability. It wasn't a huge gliding range, but it was a maneuvering capability to evade Soviet air defenses, air and missile defenses. And as I understand it, that thing did have substantially reduced accuracy, which I'm assuming is because it had to turn these very, very high G-turns. So yeah, I mean, there are, look, I mean, I'd put it this way.

There are trade-offs with all of this. If you want the advantage of a weapon, the supposed advantage of a weapon that could glide potentially enormous distances, you're going to have trade-offs that create huge challenges with creating the accuracy, which is precisely why I lean towards avant-garde at the moment only having nuclear capability.

Jeffrey 24:28

Well, I mean, one of the reasons I wanted to surface the tradeoffs is because when you get these very simplistic accounts of this kind of super weapon, right, those tradeoffs get not discussed. And so you only hear about the things that might be able to do. And there's no sense of the things that the Russians are giving up, because, frankly, I think it's a really interesting and probably not fully rational choice.

You know, if you're worried about missile defenses, I mean, I think the American assumption is always that the Russians would just build more, you know, reentry vehicles. And I think it takes a special kind of outlook to decide that actually, instead of just increasing numbers, shifting over to gliders, you know, might be part of the solution. That's an interesting strategic decision.

James 25:18

Yeah, it is. I guess I don't find it as surprising as you. I mean, you know, at the moment, we're living in a world that's constrained by arms control, at least in the form of New START. So if the Russians are going to continue to abide by New START, they can't just build more warheads. You know, I think one of the strongest arguments for New START, which I'm not overly optimistic about right now, but is that without New START, I think the Russians likely will build up their number of strategic warheads or quite possibly could.

But I guess... I guess there's various factors for, you know, from the frame of view of the Russian defense establishment, you could see the arguments for going down this route. I'm not endorsing these arguments, but just from their perspective. I mean, the first thing to say, as I've said already, If you read a lot of the news coverage about Avangard, you would get the impression that Russia did not have the ability at the moment to penetrate US missile defenses with ICBMs.

So let's acknowledge that reality, that Russia has this capability at the moment to penetrate US missile defenses with ICBMs. But let's also acknowledge that lots of senior important Russians are really worried that they're going to lose this capability in the future. Because they have this enormous belief in the ability of the US to develop ever more sophisticated systems.

So you could see them say, well, if we just build more ICBMs, if that's the only thing we do, and the Americans get some technological breakthrough, they could nullify all our ICBMs simultaneously. Having this system that has a dramatically different trajectory that's not going to be visible generally in US early warning radar, that's a qualitatively different way of penetrating US missile defenses.

And that makes some strategic sense from their perspective. The possibility that you could convert these things in the future to the delivery of conventional weapons is something that may be attractive to the Russians. And I actually think that's the big deal from the US perspective in all of this. I mean, in the nuclear war, if I get killed by a SS-19 with a nuclear warhead or by an SS-19 that launched a glider with a nuclear warhead, I kind of like I don't really care about distinguishing between those two outcomes.

I'm still dead. On the other hand, if the Russians have conventional gliders that can reach the US, that kind of seems like a big deal to me. I mean, that is a qualitatively new threat that we don't face at the moment. And final thing from the Russian perspective is the US is doing this. I mean, I can't prove this, but it seems to me that there is a genuine arms race dynamic here In that the Russian program was revitalized partly because of the US withdrawal from the ABM Treaty and partly because the US at the same time decided to invest massively in gliders.

And now, ironically, it's now coming the other way, in which one of the strongest arguments for pursuing boost glide technology in the US is the fact that the Russians and Chinese were doing it. So I guess I don't find that it is an interesting decision, but I'm not massively surprised by it.

Jeffrey 28:28

The reason that I find, it's not so much that I find it curious, it's that, you know, I have this sense that with Putin's consolidation of power, there's been a kind of revival of a lot of Soviet patterns of decision-making and behaviors. And so I think it's kind of interesting that we've seen this menagerie of absurd weapons over the past few years, you know, whether it's the The torpedo or the nuclear-powered cruise missile.

And so I guess your point, which I take, is that the hypersonic reentry vehicle is not the weirdest of those weapons. But I think, at least for me, intellectually, I still kind of slot it in with all those other things where I think, you know, it's a kind of curious sort of response to missile defense. But, you know, I take your point.

James 29:24

Yeah, I mean, my argument is more about, you know, from the perspective of whoever it is within Russia who makes these decisions, the general staff, the defense industry, whatever. You know, I'm just trying to explain from their perspective what I think their logic would be in pursuing this kind of system. And, you know, from Putin's perspective, I wouldn't underplay how much he loves the fact it gives him bragging rights.

I mean, it is... It's so... I documented a bit for a paper a few years ago just how much Putin personally had spoken about hypersonic boost glide weapons, I mean, without necessarily using that term. But for a head of state to have made, I mean, I lost count when I wrote this paper a few years ago, and I have no doubt I didn't even have all the references because I don't speak Russian.

But for a head of state to have spoken about this weapon now 10, 15 times more often is kind of extraordinary. You know, U.S. presidents, Chinese leaders just don't speak about individual weapon systems in this way. So I think he likes the bragging rights.

Aaron 30:30

Something I want to pick up on is, like, you know, you're still dead, whether it's a regular RV or a hypersonic RV. In much the same way, I think about missile defense in similar – if you conceptualize missile defense as point defense, which is what it is – How much does this actually change the equation? I mean, I don't think it's true that the U.S., particularly maybe within the European context, is totally defenseless against the sort of avant-garde superweapon-type narrative that it's often portrayed as.

James 31:06

Yeah, so I mean, there's point and area defenses, and it's worth kind of talking about that difference there. You know, point defenses are the equivalent of your defensive lineman in a foot. Oh, I screwed that one up. Point defenses are the equivalent of your cornerbacks in a football game, right?

Jeffrey 31:26

They're, they're, they're, they're trying to explain American foot.

James 31:30

My wife gave me this analogy. It's a great analogy. And then I screwed it up anyway.

Jeffrey 31:34

So now I can't believe, isn't that on your citizenship test?

James 31:39

What the difference between cornerback and defensive lineman? No. Fortunately, fortunately, I would have failed. So the point defenses are the equivalent of your cornerbacks at football. They're trying to knock the ball out of the air just before it hits the receiver's hands. I'm doing well today. And they can only defend a very small area. But the thing that's in that area, the receiver is extremely high value.

And, you know, in missile defense terms, you know, U.S. point defenses, systems like FAD, PAC-3, Aegis, they're actually not bad systems. It's the air defenses that have proved a lot less effective. The air defenses are your defensive linemen. They're trying to knock the ball out of the sky just as soon as it leaves the quarterback's hands. If they manage to do that, they can protect the whole of the downfield area.

So gliders can totally penetrate area defenses, as can ICBMs. They would actually. I think they are even better at penetrating area defenses. But that's even better. From a point defense perspective, I'm not completely convinced that gliders are an amazing way of penetrating point defenses. And I think here it's worth comparing gliders to ballistic missiles. One thing that's not appreciated is that as gliders go through the atmosphere, they slow down.

And that slow down can really be quite dramatic. So generally speaking, a glider will be moving slower than a ballistic missile when it reaches the target if the two have the same basic range. So gliders slow down because of the atmosphere. Because they're in the atmosphere the whole time, you can't protect them by countermeasures. And they produce this enormous infrared signature, which is kind of an attractive thing for a Interceptor to lock onto.

If gliders have some amazing terminal maneuvering capability, then that may be the way for them to defeat defenses. But if you compare ballistic missiles to gliders of the same range, I suspect that with the level of technology we have at the moment, gliders may actually be less effective at penetrating point defenses than ballistic missiles.

Jeffrey 34:04

That is exactly what I was going to ask because – I knew you were going there. Well, yeah. I mean there's just – that subject came up when – I mean there's a reason that RVs look the way they do. You could have brought the nuclear warheads back the way you brought like a space capsule back, right, with – With a lot of friction, but the problem is it slows down.

James 34:30

Which is exactly what the early reinterpretations were.

Jeffrey 34:33

Yeah. So, you know, we moved away from this model. Obviously, there wasn't maneuvering, but, you know, again, it's those trade-offs, I think, that are so interesting. So I have one last question to get away from the sports metaphor, in deference to Mort Halperin who hates sports metaphors. What about...

James 34:52

Sorry, Mort, if you're listening.

Jeffrey 34:55

What about... Given given the different choices for guidance, you know, you had mentioned GPS. Is it possible? I mean, I just I haven't really thought about the speed with which something is moving, whether local jamming or spoofing is is feasible in the same way that, you know, Bill Perry looked at interfering with Soviet radio guidance of early ICBMs.

James 35:24

Yes is the answer to that, I think. Any use of GPS is always going to be vulnerable to spoofing, to jamming, whatever. Obviously the bank, we could confuse it and bank everything in Canada. Well, let me, let me, if anybody from the Canadian government is listening, let me make clear that that is not the choice that I would make in this situation.

And I would like to end, reenter your country again at some time in the future. But the, the question, the real question here is over what range can you spoof? Can you, Jam can you interfere with a GPS-based guidance system? I mean, if you have a really valuable point target and you stick a GPS jam on that, like around that target, at some point that jammer is going to be powerful enough that it will interfere once the incoming weapon is close enough.

The question is over what range is that jammer effective. So, you know, could you successfully You know, if a glider is thousands of kilometers away over the ocean, interfering with its guidance at that point via jamming or spoofing is going to be really difficult. If it's 10 meters away from the target, I'm pretty sure you probably could easily jam or spoof it.

But at that point, you know, it's on the trajectory. So all GPS is vulnerable to jamming or spoofing. The question is kind of a much more detailed offense-defense question is over what range Can it be effective, and how much of a military effect can you have on the incoming weapon, given what range?

Aaron 37:05

I'm satisfied with that answer, Aaron. Me too. I was going to say. I don't, do we, do I have any more questions on this? I mean, this has been a really useful explainer for me. I, I, I have to be honest, you know, I think I said, well, Jeffrey, you said it off of the show is I'm not as familiar with this missile system as we are other things we talk about on this podcast.

So it's just been great to learn about it.

James 37:26

Can I, before we finish, there's two other issues I just had in my mind to flag up that I think is worth just flagging up. The first one is avant-garde and new start. Because Avangard is based on the SS-19 booster, which is covered by New START, my reading of the treaty is Avangard is going to have to be treaty accountable.

If it's really true that Russia is now deploying this system, then we're going to find out the answer to this question pretty quickly. And I think it's going to be really interesting over the next few weeks or months to see how the deployment of Avangard affects New START. The second thing, which I'll just kind of, the last thing I want to say is I realize that there is a real challenge talking about this system without displaying the name.

Because I think a lot of people actually have got the name wrong of this system. When you Google Putin avant-garde, what comes up on autofill is Putin avant-garde, like A-V-A-N-T, New word, G-A-R-D, like, you know, avant-garde. But it's actually one word, A-V-A-N-G-A-R-D. Do you know what it means in Russian? You know, I don't, actually. The other system that they've announced, Kinjal, is dagger.

I actually don't know what avant-garde means in Russian.

Aaron 38:59

I don't speak any Russian, so that's...

Jeffrey 39:01

I'm just keeping all my jokes reasonably pod safe.

James 39:05

I mean, I thought that Google autofill story was kind of funny, but it led ballooned. It was like a glider that fell out the atmosphere.

Jeffrey 39:15

Well, I was waiting for you to make a serious point because I actually had a question, which is, I gather the Russians use Avangard to refer to the entire system, the booster and the reentry vehicle. But obviously the booster is a known missile, the SS-19, and so... I wonder if it actually refers to just the glider or if it refers to the system of the glider and the booster.

James 39:41

It's a good question. I genuinely don't know the answer to that one. The glider was referred to for a while as, I think it was U71. I could have the exact number there wrong. I have seen a separate name for the glider. It wouldn't surprise me if it was actually the entire system. But as I say, I don't know.

Jeffrey 40:04

As you said, many things we do not know about the avant-garde.

James 40:07

And I think that's a good takeaway. If you step back from all the breathless media reporting, my main takeaway of this system would be there is a lot we don't know. I mean, it could be anywhere from a big yawn to a fairly BFD. But there is a lot we don't know about these capabilities.

Aaron 40:28

Is there anything else you want to hit, Jeffrey, before we wrap up here and you go back to your farmhouse and you have a roaring fire in your herbal teas?

Jeffrey 40:36

I'm in the farmhouse, and I've been asked not to use the fire, and I have appealed that decision. I'm going to spend four weeks in Vermont with no fire.

Aaron 40:47

How is the tea kettle? Is it a kettle or is it like an actual – It is a harmonic kettle.

Jeffrey 40:52

And I'm drinking well water, and so the amount of mineral condensation... What are you? I'm in a farm in the middle of nowhere that I rented for my family that's not coming.

Aaron 41:06

Jill has sanity. Good choice, Jill. I have a three-bedroom house.

Jeffrey 41:16

And I'm just freezing in this empty three-bedroom house where I teach two hours a day and spend the rest of the day just wandering around like, what am I doing? By this time, this podcast is over. Buying any scotch? Because I figure I'm terrified I'm going to turn into Jack Nicholson.

James 41:36

Geoffrey, by the time this podcast is over, you're not going to have to enter Canada again. You're never going to be allowed back into Vermont again. Anyone else you want to be banned from?

Jeffrey 41:45

You know what? I actually like Vermont. I mean, it's cold. And that's a problem. But I went to the I went to the co-op, the grocery store in Middlebury. And it's quite lovely. Like I could I could I you know, it's a it's a surprisingly livable place up here in the land of Bernie. Surprisingly livable.

James 42:09

If anyone from Vermont is listening, I apologize for Geoffrey.

Jeffrey 42:14

Well, I'm used to the beach. Like, I'm used to, like, when I'm in class, I go watch, you know, dolphins frolicking in the surf. Now I've got, like, cows. Going from dolphins to cows is a pretty big back off.

Aaron 42:32

We've gone off the rails here. That usually means we're done.

Jeffrey 42:37

Anytime you want to remind listeners about the subscriber benefits of Patreon.

Aaron 42:43

Glory to the Slack channel. So listeners who want to hear more about Jeffrey's snow excursions in Vermont, you can go to patreon.com slash atwpodcast. And if you are a student with a .edu address, it's $3 a month for everybody else. It's $5 a month to get access to our podcast. Slack channel where we also host a separate short pod called Brilliant Pebbles a couple times a month where we talk about something cool in the arms control, non-proliferation, or disarmament space.

And Jeffrey is known at some time for post-cocktail picks. So with that, Jeffrey, stay warm. And James, cheers to not drinking well water. Thanks for joining us. It's been a pleasure. Thank you, guys.