U.S. Air Force says it conducted successful hypersonic weapon test

>All ballistic missile reentry vehicles are hypersonic too

Sure, but ballistic trajectories are trivially interceptible. It's not just about speed. The new arms race is with hypersonic glide vehicles that are capable of maneuvering all the way to the target at mach 8+. With that, the weapon becomes impossible to intercept with any existing technology.

The Russian "hypersonic" missile is just the upper stage of a short ranged ballistic missile launched from an aircraft. Its just an existing weapon with more steps.

The Chinese hypersonic weapons everyone is worried about is a boost glide vehicle. Basically a ballistic missile with a hypersonic lifting body as its warhead as opposed to a blunt body RV you usually see. This makes it more maneuverable and potentially harder to hit.

The weapon the air force tested today is similar to that but meant to be launched from bombers instead of ground launched.

The actual scary ones are hypersonic cruise missiles. Nobody has fielded one operationally yet. But the US is by far the furthest ahead in this technology. In march they had a successful test of HAWC the Hypersonic Air-breathing Weapon Concept. Scramjet powered cruise missiles like HAWC are more dangerous than conventional ballistic missile or boost-glide missiles because they actually fly. And therefore can do the things normal cruise missiles like Tomahawk can do. They can take circuitous routes. They can change their altitude. They can fly somewhat evasively. They can fly to an area and pick targets of opportunity. And other things.

Why does it matter? We've gotten much better at shooting down conventional cruise missiles. A few years back an Arleigh Burke destroyer had a number of Chinese built subsonic anti ship missiles fired at it by Houthi Rebels. It shot down every single one of them. These missiles are comparable to the Neptunes that recently sank Moskva in terms of performance. So modern warships aren't as vulnerable as Soviet era antiques. You need better weapons to kill them. hypersonic cruise missiles are much harder to intercept. Boost glides are of dubious utility in my opinion.

The Pentagon does this every decade. They constantly need some sort of existential threat to respond to in order to justify budget increases.

They have already denied the US the South China Sea -- just by expanding their economy. The US is a joke here. China -- for example -- in the last 20 years has started more than 400 companies in the Philipenes at least and where else? Structural changes to the economy, basically. While Europe and the US persist in this 1970s: "we will give the primitives subsidies and cash prizes" -- demonstrating that they are totally out of touch with the region. Colonialism is over. These countries have money. China is actually installing economic zones and other structures which give them direct control over the region. Aircraft Carrier Groups are no match for this.

I'm not saying I like or dislike it. But its incrediably evident if you live in the region.

The US also overestimates the threats from its potential adversaries quite frequently. The Soviets weren't 10ft tall, and the modern Russian military has been shown to be quite fragile in Ukraine. Perhaps military intelligence is a bit harder than posting on HN.

And destroyed the first submarine that tested them! Russian, the typical failure of a new torpedo is guidance, which often results in the device describing a circular route instead of a straight one. Ending up back where it started. So they fired, and before you could say Jack Robinson it hit them, having traveled in a circle of a mile or so.

Or so I recall from reports after the fact.

I think it's hard to argue that MAD isn't in effect right this second. If there was no threat of massive retaliation and possible resulting extinction is there any doubt Russia would have used nuclear weapons in it's Ukraine invasion?

Stressing that advanced hypersonics is venturing past nuclear MAD but building towards conventional MAD made feasible by proliferation of advanced rocketry as dual-use components become commoditized and US/west lose monopoly on space infra used for targetting/guidance. It's a new kind of mutual vunerability where strategic infra that underpins modern society i.e. semi fabs, server farms, energy nodes, captial ships docked for maintenance etc can be targetted by more and more players.

In terms of practicality, we were "stuck" with nuclear MAD because meter level surgical intercontinental strike capbility has so far been pipe dream. With nuclear MAD, we had stability-instability paradox, increase chance of low level conflicts against non nuclear states while nuclear states operated with relative impunity. Conventional MAD = even 3rd rate countries can potentially import a bunch of global strike ICBM platforms to threaten pain points of any would be attacker. Most countries can't sustain modern airforce let alone forward project carrier groups, but many countries can build some concrete tunnels to hide sufficient amount ICBM TELs to increase deterrence. It's not nuclear tier deterrance, but ability threaten some critical infra is better than current posture where most countries can't inflict pain more than a few hundred km outside their borders.

I don't know how things will change but my position is balance will have to shift once advanced rocketry proliferates because that's boat that everyone will want to rock simply because dual purpose conventional rocketry won't be subject to arms control. It's going to be about how states with advanced rocketry programs can control proliferation, i.e. US wants to seed Asia with IRBMs that can threaten PRC, and PRC starts exporting hypersonics to South America or other countries that can threaten US global assets.

The CNN article is taking the definition of an HGV entirely out of context from the underlying CSIS article it links. From the CSIS article:

> Russia’s Northern Fleet has begun preparations to deploy the air-launched ballistic missile Kh-47M2 Kinzhal on MiG-31K carriers. The deployment of the new hypersonic weapon is consistent with Russia’s ongoing and persistent efforts...

Not all hypersonics are HGVs/skip-glide weapons.

The problem with military spending is that if you choose your investments very judiciously, you end up not being attacked. And if you are not attacked, it looks like all the investment was for nothing.

20+ years of the "Global War on Terror" really ground down our military capability across the board. Systems were pushed past the breaking point in a short-sighted attempt to hold down costs. Now if we're going to continue having an effective military at all then we're going to have to recapitalize everything. That is the budgetary reality. If we want to reduce the intended mission set and scale down the military accordingly then that's an option, but it means surrendering control of the Asia-Pacific region to China. Would that be better?

Barely within the atmosphere, I assume. Mach 20 at commercial jet altitudes would probably melt the aircraft.

Ask Putin about how useless having nukes is for preventing NATO involvement in the Ukraine...

> We have hundreds of Aegis boats

113, if you count Japan's, Korea's, and the rest of NATO (with 137 more planned.) These are spread around the world, and only some of them are Aegis BMD. And not all of those will be ready when they're needed. A few dozen Aegis BMD ships off the coast of the US seems plausible.

Besides Aegis, there is THAAD (which only protects a handful of rather small areas) and GMD (which only has a few dozen interceptors.) If China/Russia threw hundreds of missiles at the continental US all at once, it's a good bet that at least some would get through and wreck havoc.

The aegis you are talking about are mainly dedicated to protecting CVNs

Aegis is continually evolving with new sensors, processing, and missiles and far from obsolete. It's no coincidence that China is building similar capabilities into its own Destroyers.

I definitely would't call the scale of missile defense in the fleet limited. Each carrier group would contain and be screened by Destroyers and Cruisers with several hundred interceptors ready to go between them.

The navy is close to adding lasers to its point defense array

Wow really? I missed out on that one. Thanks for the update.

Per OP:

> The U.S. Air Force said on Monday it had conducted a successful test of a hypersonic weapon, which flew at five times the speed of sound.

But to your question:

> around Mach 10-20 is where the tradeoff could become non-obvious, depending on how much you value weighing less?

The same logic holds at mach 5-8 (ie current hypersonics), which is why they’re being developed:

You want a weapon that can surprise, evade, or penetrate better — even if that’s less destructive overall.

When close to the ground, something flying at Mach 10-20 would either be deccelerated very quickly to much lower speeds, if flying passively, or require a very large mass of fuel to maintain the speed.

Moreover, it would be hard to avoid being partially vaporized before reaching the target. So hitting something at Mach 10-20 seems much more difficult than filling the missile with explosives and detonating it.

Weapons based on kinetic energy alone seem practical only against satellites or against targets that fly in the upper atmosphere.

Completely agree. Those systems solve a bunch of non-problems and completely destabilize MAD. There's a reason they were never developed.

But I wouldn't discount to the ability of weapons designers to figure out the frangibility and deliver the bulk of the energy to a tuneable depth.

Drop a deuce from Zeus?