High-speed hype? The problems with hypersonic missiles

With an arms race ongoing between the United States, Russia, and China to field new hypersonic weapons, the internet has seemingly drawn battle lines between two camps: those who believe hypersonic missiles represent the future of warfare, and those who think these new weapons create more problems than what they’re worth.

Like so many raging debates on social media and in the comments beneath articles like this, the internet’s distaste for nuance would have you believe that there’s only one correct answer when it comes to hypersonics. Continued investment in these weapons is either a life-or-death enterprise or an exercise in media hype and the military-industrial complex’s insatiable need for urgent new defense initiatives to pad investor pockets. But the complicated truth is, that hypersonic missiles can be both game-changers and entirely unnecessary — and the defining variables between the two come down to how they’re developed, built, and leveraged in a fight.

Hypersonic missiles come with a whole litany of technological, economic, and geopolitical problems that may render some high-Mach efforts practically useless, and others extremely vital. Yet most… are still somewhere in between.

We’ve covered the types of hypersonic weapons being developed and their uses at length before. So, in the interest of providing balanced context, this time we’re going to discuss some of the biggest problems facing hypersonic missiles today, and why the way a nation addresses these problems will dictate the actual value of these systems in 21st-century conflict.

But first, here are some important things to keep in mind when discussing hypersonic weapons in general.

Related: Is America really losing the hypersonic arms race?

Some important context

Hypersonic is a term used to describe vehicles that can travel at speeds in excess of Mach 5 or around 3,838 miles per hour — but the phrase “hypersonic missiles” has come to mean something much more complicated in modern parlance. Technically speaking, ballistic missiles have been reaching hypersonic speeds since their very inception with Hitler’s V-2 rockets, and the United States (as well as many other nations) already has massive stockpiles of weapons capable of achieving these speeds.

As one example, America’s nuclear Minuteman III ICBMs, which have been in service since 1970, fly at speeds in excess of Mach 23. When people refer to hypersonic weapons today, what they really mean are missiles that can travel at these extreme speeds and maneuver along the way—and it’s that maneuverability combined with speed that makes them so difficult to intercept.

There are only two forms of modern hypersonic weapons that we can confirm meet this “un-interceptable” criteria: hypersonic boost-glide weapons, and scramjet-powered hypersonic cruise missiles. Russia and China each have one of the former in service, in the Avangard and DZ-ZF respectively. No nation has managed to field an operational hypersonic cruise missile to date, but the United States seems to have the inside track in that regard.

Hypersonic Boost Glide Vehicles (HGVs) aren’t all that different than the warheads on traditional long-range ballistic missiles, at least in the early stages of their flight path. They are carried into the upper atmosphere via high-velocity boosters but are released at lower altitudes. They then glide at high speed (Mach 20 or more in some cases) down toward their targets unpowered. Hypersonic cruise missiles, on the other hand, use experimental propulsion systems called scramjets to fly more like aircraft at hypersonic speeds, flying along a fairly horizontal flight path at speeds as high as Mach 10 or even better.

At speeds above Mach 5, a maneuvering weapon would be practically impossible to stop with existing air defense systems — and that’s where the value of these weapons can be most easily appreciated.

Related: America may have just taken the lead in hypersonic cruise missiles

The biggest problems with hypersonic missiles all come down to cost

A recent Pentagon estimate suggested that the hypersonic missiles the United States Air Force has in development may cost as much as $106 million each, and that’s a serious problem. Despite having the largest defense budget on the planet, the United States military also has the highest operating costs, thanks to a high level of training and standard of living for its troops, truly globe-spanning obligations, and its reliance on advanced technology.

So, while it may seem like there’s nothing Uncle Sam can’t afford… the truth is, he really can’t afford to stockpile $100-million missiles. The Navy’s hypersonic weapons are expected to be cheaper, at a still-daunting $89.6 million per unit. Some estimates place the lowest-costing U.S. hypersonic missile price at only $40 million per missile… but that still represents a massive price tag for a single weapon.

In 2021, the Pentagon reported the per-unit cost of the Air Force’s F-35A was about $78 million. In other words, a single hypersonic missile can cost more than one of the most advanced aircraft in history, and even the cheapest hypersonic missiles ring in at around half the cost of America’s top-tier stealth fighter.

That high cost doesn’t just make it difficult (if not impossible) to purchase large volumes of these weapons, but it also shines a light on one of the biggest criticisms levied toward these weapons…

Related: The groundbreaking hypersonic missiles America has in the works

Hypersonic missiles often don’t do anything that cheaper missiles can’t already do

The most commonly cited selling point for hypersonic missiles is that they can’t be stopped by existing air defense systems, but that argument itself comes with its own problems. As we’ve discussed on Sandboxx News before, nations have a tendency to overestimate the efficacy of their missile defense systems in public discussion for good reason. Deterrence is a game of managing perceptions, so you’ll be hard-pressed to find a nation making statements to the global media about just how easy it already is to get missiles past their defenses.

In April of 2018, the U.S., U.K., and France fired 105 subsonic cruise missiles at targets in Syria tied to a chemical weapon attack on civilians that occurred the week prior. The U.S. and its allies reported the attack was an overwhelming success, but Russia countered in the press, arguing that they had managed to intercept more than 70 of the inbound weapons. Intelligence gathered in the days that followed substantiated America’s claims, with reports from the three nations showing that Syrian forces fired more than 40 interceptors at the inbound missiles without successfully destroying a single one.

But even if Russia was telling the truth, it would still mean their air defense systems let 30 or more slow-moving weapons cruise on by to find their targets. The majority of the weapons used in this strike were Tomahawks that travel at around 550 miles per hour — more than 3,000 miles per hour slower than the slowest hypersonic weapons.

Even if modern air defense systems like Russia’s S-400 or America’s Patriot missile system, were magically capable of having their interceptors find their targets 100% of the time, all it would take to defeat them would be launching more missiles than they have interceptors for. And that’s where the question of cost comes in.

America’s subsonic Tomahawk cruise missiles come in a variety of forms, but the most modern iterations ring it at around $2 million each. Contrast that against the $100 million unit cost of hypersonic missiles and the problems become evident: You could launch 50 Tomahawks at a target for the same price as a single hypersonic weapon. The math associated with intercepting a single missile moving at speeds above Mach 5 is too complex for systems to manage today, but the fact of the matter is, that a high volume of lower-cost weapons could prove just as effective as a low volume of high-cost ones in a large number of mission sets, and these lower-cost weapons are already in service today.

Related: Hypersonic hype overestimates modern missile defense systems

Hypersonic weapons aren’t necessarily faster than existing missile systems

A common argument in favor of hypersonic weapons is their ability to reach their targets at extremely high speeds, which can be vital in situations when intelligence suggests an important target is in a location but may not be for long. But the truth is, hypersonic missiles don’t necessarily travel any faster than other, cheaper missile technologies.

As we discussed above, ballistic missiles also travel at hypersonic speeds, but are limited in their maneuverability as compared to modern hypersonic weapons. But, when trying to engage a target within a tight window of time, ballistic missiles could actually be more effective than advanced hypersonic ones. Hypersonic boost-glide vehicles begin their flight paths similarly to ballistic missiles before they separate to glide and maneuver toward their target. Ballistic missiles, on the other hand, don’t glide or maneuver — they just follow an arcing ballistic flight path directly into the target at high speeds.

The same maneuverability that makes modern hypersonic weapons special can also make them slower in some circumstances, as they change course to make their interception harder. Changing directions increases both friction and distance, while Ballistic missiles fly straight at their targets. Of course, air-launched ballistic missiles (like Russia’s Kh42M2 Kinzhal which they claim is a hypersonic weapon) can be easily misconstrued for nuclear weapons, so they’re not commonly employed by most nuclear nations.

Related: Why calling Russia’s Kinzhal a ‘hypersonic missile’ is a stretch

Not all hypersonic weapons provide important or needed capabilities

While Russia’s Kinzhal missile isn’t all they’ve claimed it to be, the nation’s hypersonic follow-up, the Avangard boost-glide system, is indeed a hypersonic weapon in modern terms. But because it’s a nuclear weapon, it doesn’t actually create any kind of strategic value. In a real way, Avangard is a hypersonic missile developed mostly to give Russia the opportunity to say they have hypersonic missiles for the sake of garnering global press coverage and appearing to be on the cutting edge of defense technologies.

It’s no secret that America’s midcourse defense system, the air defense apparatus intended to protect the U.S. against nuclear attacks, could not stop a Russian nuclear attack if it were to occur. Russia currently has a stockpile of some 4,477 nuclear warheads, with more than 1,500 deployed on ballistic missiles and aircraft. If Russia were to launch a nuclear first strike with just half of its nuclear ICBMs, America’s defenses would be completely overwhelmed and unable to prevent the majority from making landfall.

So, if Russia could already turn the United States into a nuclear wasteland with decades-old missiles collecting cobwebs around Siberia, what difference does it make that they could also launch some of those nuclear warheads in extremely fast boost-glide weapons? The truth is, it makes no difference at all, and that’s why the U.S. isn’t working to match Russia’s nuclear hypersonic capabilities.

Just having a fast new weapon doesn’t actually matter if there isn’t a valid use-case for it.

Related: Russia’s massively powerful nukes are strategic duds

So, are hypersonic weapons worth it?

Hypersonic missiles come with a long list of problems, technical challenges, and budgetary hurdles —but there’s still some serious value in developing and fielding this technology. The question, “are hypersonics worth it?” is too complex to answer with a simple yes or no, however, because the value in hypersonics comes more in how they’re integrated into an overarching combat strategy than in their specific individual capabilities.

This point was perhaps best summarized in a discussion I had with former F-15 weapons officer and founder of the fantastic aviation newsletter, “The Merge,” Mike Benitez recently. Benetiz served as an enlisted Marine before transitioning to an aviation career in the Air Force. After his time in uniform, Benitez went on to work on Capitol Hill in the Office of Senator Mike Rounds, as well as doing analysis work for a variety of reputable defense outlets.

“Weapons aren’t that different than any military program—they are developed with specific features to solve a specific problem,” Benitez said.

“If a weapon’s design cannot stand up to the test of interoperability and complimentary, then there should be serious debate on why they are being developed and deployed in the first place.”

Developing hypersonic weapons in a hurry just to win the headline war over who will claim to have fast missiles first does offer international prestige and attention. Therefore, it’s important to point out that winning the headline war can help a country like Russia achieve some strategic goals, for example, military modernization through increased arms sales, by marketing itself as a leader in the field. However, the United States has little to prove when it comes to fielding advanced military technologies, and has instead prioritized fielding weapons that offer real tactical capability that creates reverberating strategic effects.

That approach is less headline-friendly but is ultimately aimed at winning wars, rather than garnering attention. The nuanced truth about hypersonics is that they can offer game-changing capabilities in a near-peer fight if leveraged with distinct use-cases in mind…

Or they can offer a very fast-moving hole to throw a whole bunch of money in.

The truth is, fielding the first, or even the fastest hypersonic missile doesn’t matter nearly as much as fielding the right one that creates new combat opportunities or fills an urgent need. Making fast missiles just to say you did is one thing… lobbing them at barns in Ukraine may even be another… but winning the hypersonic arms race is a question of value-added, not headlines garnered.

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