Hypersonic missiles don’t make much sense. I mean they do and they don’t. While most claims
about hypersonic missiles are totally overhyped, one claim is the real deal. It has to do with
the word “hypersonic”, which means traveling at speeds exceeding five times the speed of sound.
As it turns out, 5 is actually a magic number. But the more you look into the physics of hypersonic
flight, the more you realize that “hypersonics is the technology of the future and will always be”.
That’s not my line. It was in fact a running joke among the Air Force engineers who developed the
X-51 Waverider – an experimental aircraft capable of hypersonic flight. But there is a lot of
truth to that joke, because creating a hypersonic missile involves solving some extremely difficult
problems. The funny part is that even after solving all those problems and building a reliable
hypersonic missile, as you’ll see, its utility is really questionable, which begs the question,
why build a hypersonic missile to begin with?
A hypersonic missile travels between Mach 5 and Mach 25.
Traveling at such high speeds would allow a hypersonic missile, hypersonic glide vehicle or
a hypersonic aircraft to outrun all enemy air defenses, making it practically invulnerable.
Hypersonic weapons in general are harder to counter than traditional rockets because
they can travel fast, for extensive periods of time, and are maneuverable.
This makes them less predictable than traditional ballistic missiles. Basically, the narrative goes
that with hypersonic weapons, you can do whatever you want over enemy air space, and there is
nothing they can do about it. At least that's the idea, but we are yet to see it in practice.
And no, the Russian Kinzhal hypersonic missiles don't count. We’ll get to that too!
So why Hypersonic? Why mach 5? Why not mach 4 or mach 6? While it may not matter to a hypersonic
glide vehicle, the Mach 5 is a magic number for a hypersonic cruise missile – because of the type of
engine used. There are various types of engines and each works best at a particular speed.
Turbojets use a series of large fans to draw air into the engine and pressurize
it. This pressurized air is then mixed with fuel at subsonic speeds and ignited.
The exhaust that leaves the engine creates thrust which pushes the engine forward.
The advantage of turbojets is that they can start up from a stationary position,
but the downside is that they are most efficient at subsonic speeds.
Turbojets start losing efficiency at transonic speeds, with not much utility above Mach 3.
Ramjets eliminate the fan and use their forward momentum and shape to intake the air from outside,
slow it down to subsonic speeds, and pressurize it. Fuel is then injected and ignited,
which generates thrust. But for a ramjet engine to work, it has to be already moving.
Theoretically, ramjets can start at Mach 0.15, realistically at Mach 0.5,
but they only reach their full efficiency at around Mach 3. Their theoretical maximum
operational speed is mach 6 and that’s due to shockwave-induced pressure loss.
Finally, scramjet works the same way as ramjet, with the key difference being
that scramjet doesn't slow down the air to subsonic speeds before mixing in the fuel.
This allows scramjet to operate more efficiently than ramjet at higher speeds. In fact,
scramjets are capable of the highest possible propulsion speeds, all the way up to Mach 24.
While it might have the most simple design among these engine types, it comes at a cost.
The scramjet can only start operating at about Mach 5. Depending on altitude and atmospheric
conditions, it could start at Mach 4.5 also. Since scramjet can only operate at high speeds, it would
have to be boosted up, either by a rocket, or dropped from an airplane such as a B-52.
But here’s the thing: while scramjet might look simple, in reality, it's incredibly hard to get
it to work. Scramjets have been in development for the past 70 years. The issue is that everything
is happening incredibly fast inside the engine, at hypersonic speed! In a matter of milliseconds, the
right amount of fuel has to mix with air at the right pressure to create the magical scenario of a
sustainable combustion cycle. Even more difficult, is to make the whole process reliable.
But if scramjets are so difficult to operate, why not just use rockets?
Great question. And yes, you can use rockets that fly at hypersonic speeds.
The world's first long range ballistic missile, the German V-2, was actually able to reach
speeds greater than Mach 5 for a brief period of time during ascent. Modern ballistic missiles,
such as the Russian Iskander, can reach speeds of up to Mach 7 in the stratosphere.
Intercontinental Ballistic Missiles or ICBMs reach speeds of over Mach 20 while cruising in space.
But, there are two problems with ballistic missiles: predictability and efficiency.
Once a ballistic missile’s rocket engine burns out, the payload is basically coasting at a
set trajectory, making it easier to intercept as the payload slows down from hypersonic to
supersonic speeds. In fact, a great advantage of hypersonic glide vehicles over ballistic missiles,
is their ability to maneuver while in flight, making them less predictable,
which poses a great problem for missile defense systems.
I recently came across a story that Iran announced it too has built a hypersonic ballistic missile,
but it was interesting how some news outlets were using different headlines to cover it,
thanks to Ground News, an app and website that I’ve been using to stay fully informed
on breaking news as it’s happening around the world, and they are sponsoring this video.
This particular story on Iran has 92 sources reporting on it with 56% of the sources from
right leaning outlets, making this a potential blindspot for the left.
Scrolling down, I can see all the news sources and compare headlines from left, center,
and right leaning outlets. For example, WND a far right source with low factuality headlines
this as “Iran claims to have built hypersonic ballistic missile” while the Daily Mirror,
a left leaning source with mixed factuality reports headlines the story as “Iran builds
unstoppable hypersonic missile that can fly 5 times speed of sound.” It’s really helpful to
see it visualized this way where a single word or phrase can alter our understanding of a story.
Ground News aggregates over 50,000 sources in one place so we can compare coverage,
see factuality and ownership of sources reporting on topics like this.
I also like that you can filter by factuality of the source and click in to read each
article from its original source. Ground News has become my go-to resource
and I highly encourage you to check it out at ground.news/nwyt for free or subscribe
for unlimited access to support this channel and a small team of media outsiders looking
to hold media accountable and fully inform readers to empower critical thought.
The second problem with ballistic missiles, or rockets in general, is efficiency,
or lack thereof. This is why we don’t use rockets to fly from New York to London and never will.
Yeah I said it! … Because it would be inefficient.
Missiles and vehicles that are powered by air breathing engines are much more
efficient in transporting a payload from point A to point B, than rockets are.
Air breathing means that the engine uses oxygen from the atmosphere as an oxidizer,
as opposed to rockets that carry their own oxidizer and don’t rely on external oxygen.
Depending on the exact model, cruise missiles can be 20 to 30 times more efficient than rockets.
How so? It has to do with “Specific Impulse”.
Specific Impulse is a measure of how efficiently an engine generates thrust.
Let’s say you have an engine where 1 pound of fuel creates 1 pound of thrust for 200 seconds.
The higher the specific impulse number the higher the efficiency.
For modern rockets, the specific impulse measure ranges from 200 to about 450 seconds. Compare
that to a scramjet, which can have a maximum value of specific impulse of
4000 seconds. The bottom line is that air-breathing jet engines typically have
a much larger specific impulse than a rocket, making them much more efficient than rockets.
This translates to longer range, larger payload, and higher constant velocity cruise
in the atmosphere compared to smaller range and variable velocity of ballistic missiles.
Nevertheless, ballistic missiles still have a speed advantage compared to subsonic and
supersonic cruise missiles, which makes them harder to intercept.
A true hypersonic missile could only be powered by a scramjet engine, not rockets.
Otherwise the German V-2 can also qualify as a hypersonic missile.
But besides problems with developing a scramjet engine,
there are many other issues with hypersonic flight.
First of all, the missile travels so fast that it compresses the air molecules to the point that
they turn into plasma. The missile becomes a large glowing object, which can be detected by visible
and infrared sensors – even from space. The claims of plasma “stealth” is nothing short of an urban
myth, because hypersonic missiles can be easily tracked by modern radars. Furthermore, a recent
Air Force Institute of Technology study found that plasma sheath is primarily reflective.
The second issue is the communications blackout at hypersonic speeds. Similar to a space shuttle
experiencing communications black-out during its return to earth, a hypersonic missile is unable to
send or receive communications. This is because the plasma sheath blocks radio frequencies.
On top of that, the hypersonic missile would be totally blind since it can’t use
any visual or infrared sensors in front of the missile, because they would simply melt.
Finally, the biggest problem is heat. Traveling at Mach 5 would heat up the missile to anywhere from
3200°F to 4000°F, which makes you wonder, how do you prevent the missile from melting? Because the
silica tiles used on space shuttles won’t work as they’d create a lot of aerodynamic problems.
One solution is to make a missile with double walls, where fuel acts as a coolant.
Currently the issue of heat is partially mitigated by flying
the hypersonic missiles really high up, somewhere between 65,000 to 130,000 feet,
where the air density and temperatures are a fraction of what they are at sea level.
This brings us to the grand finale, on why hypersonic missiles don't actually
make much sense. Here is what I mean: In order to approach its target on the ground,
the hypersonic missile would have to come down, to the warmer and denser atmosphere, where it would
simply melt down like a meteorite. To prevent the melting, the missile would have to slow down to
speeds similar to conventional missiles, and this is where hypersonic missiles stop making sense.
A conventional ballistic missile travels at an average speed of Mach 2.2, up to a
maximum speed of Mach 3 during its terminal phase. Remember the magic number? It wasn’t 3, it was 5.
This means that the Scramjet engine on the missile won’t work at Mach 3. So during its terminal
phase, the no-longer hypersonic missile is flying unpowered – just like a ballistic missile.
There will be some degree of maneuverability using small fins and gas agents to help change
its course as it plunges down, but the point I’m trying to make, is that during its final approach,
a hypersonic missile would present the same level of threat to modern surface-to-air
missile systems, that a ballistic missile, like the Russian Iskandar would do.
Of course, for now, hypersonic missiles cannot be intercepted during their midcourse phase,
when they actually fly hypersonic. And yes, they reduce the reaction time available to the other
side, to make a call to intercept. But if you are a high value target like an aircraft carrier,
no matter the reaction time window, all attempts to intercept would be made during
the terminal phase. So what's the point of even developing hypersonic missiles?
It's really hard to find any reasonable explanation besides the American Prompt Global
Strike capability, which aims to provide a precision-guided conventional weapon,
airstrike anywhere in the world within one hour. Basically the same way as a nuclear ICBM does.
It is theoretically possible for a hypersonic missile to go to 90,000 feet, fly at mach 24,
travel 7,500 miles in 24 minutes and hit some cave where ISIS leaders are having a meeting.
That would be the point … I guess?
Of course this analysis is solely based on publicly available information about
hypersonic missiles. Maybe there are some classified materials that discuss how these
missiles can travel in lower parts of the atmosphere hypersonically, without melting.
But probably not! So let's talk about Mother Russia’s hypersonic claims!
Russians claim they have two hypersonic missiles – Kingal and Zircon. But do they really?
In the case of Kingal, it's actually an Iskander ballistic missile air-launched from a MIG-31.
It is marketed … cough cough ... “propaganda”, as an “unstoppable hypersonic” weapon.
If Kingal is a hypersonic missile, so is the German V-2 from the 1940s.
But what about the Zircon hypersonic missile? On Russian TV, it was claimed that Zircon traveled
620 miles in 2 minutes. That would mean an average speed of Mach 24 … For reference,
none of the American scramjets built to date are capable of speeds over mach 6. But forget about
that, let’s just examine the footage of Zircon hitting its target barge at “hypersonic” speed.
Not much damage for a hypersonic missile. Of course the Russian government says that’s
because the missile didn’t have an explosives warhead, which is funny, because the Hypersonic
Air-Breathing Weapon Concept or HAWC is capable of traveling at Mach 5 and destroying its target
solely using its kinetic energy, which is equivalent to a few tons of TNT. And this is
the impact of Zircon traveling over 620 miles in two minutes, with an average speed of Mach 24.
And this is why hypersonics is the technology of the future, and will always be!
Hahahahahah … Yeah, I still don’t see why those engineers found it funny!