
Raytheon discloses future lasers that can stop hypersonic missiles - relaxy
https://defence-blog.com/army/raytheon-discloses-future-lasers-that-can-stop-hypersonic-missiles.html
======
averros
The future missiles are going to be shiny.

As in "mirrors".

The BIG SECRET of directed energy weaponry is that there's a very simple and
cheap method of reducing absorbed energy by orders of magnitude - reflect it
in arbitrarty directions (or even towards the source if one wants to be
naughty).

The sensors (which have to absorb EM radiation to function) are vulnerable,
but can be easily protected by shutters for the duration of attack. Modern
inertial navigation units are well capable of providing precise guidance
without any external data.

~~~
StrangeDoctor
Just have a wide range of frequencies you can use, every material absorbs some
part of the EM spectrum

~~~
A2017U1
An ablative covering negates this.

Hope they have enough time to aim in the same spot.

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drinane
The production value of that video had me gut busting in laughs... did they
pull an PS1 intro video from strike series or something lol

[https://www.youtube.com/watch?v=qyQ5Jf7cpLY](https://www.youtube.com/watch?v=qyQ5Jf7cpLY)

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yasp
> _When it comes to ballistic missile defense, “you want to get it into
> airborne platforms and into space,” said Evan Hunt, a former U.S. Air Force
> navigator who now works in business development for Raytheon’s high-energy
> laser products. “It’s better to look down than to shoot up.”_

What about atmospheric interference? (And whatever unfortunate soul might be
behind the missile assuming the laser misses.)

~~~
derekdahmer
It’s also against international law to put weapons in space.

~~~
CamperBob2
Who's going to stop them? The international police?

~~~
jandrese
It would be pretty amazing to see Interpol knocking on the doors of the
Raytheon corporate HQ.

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SamBam
> Lastly, there’s the “line-of-sight” problem; lasers shoot perfectly
> straight, meaning a laser shot toward the horizon will eventually hit the
> Earth’s curves.

Huh, and here I thought the Hollow Earth theory had been discredited, but I
guess I might believe Raytheon and its lasers. Cyrus Teed would be so pleased.

~~~
gnode
I'm not sure what the earth being solid or hollow has to do with this. If
you're on the surface of a ball, you can only project a laser / straight line
over the hemisphere above you; not through the ground.

As an example, if you're at the North Pole and the South Pole base fires a
ballistic missile at you, you can't aim a laser at it, as it would
diametrically intersect the Earth.

Instead, you have to wait until the missile passes your horizon. The point at
which it does this depends on its altitude. Hypersonic vehicles attempt to
make interception harder by reentering the atmosphere from space earlier than
a traditional ICBM, and travelling at a lower altitude in their final phase.

~~~
chc4
I think it was a joke. The way the quote was worded makes it sound like the
Earth is curving _upwards_ \- if you shoot straight to the horizon you'll hit
air, not the ground.

~~~
Mvhsz
To me it sounded like a journalist's awkward wording of a description from an
engineer. Some frequencies of light will bend to the curvature of the earth
due to the atmosphere[1]. Lasers apparently "hit the Earth's curves" rather
than bending with them.

[1][https://en.wikipedia.org/wiki/Atmospheric_duct](https://en.wikipedia.org/wiki/Atmospheric_duct)

~~~
a_e_k
This happens everyday with the sun during sunrise and sunset [1]. When you
first see the apparent top of the sun during sunrise, the sun is still well
below the horizon physically. It's just that the image of the sun is refracted
around the curvature of the earth a bit.

[1]
[https://en.wikipedia.org/wiki/Sunrise#Angle](https://en.wikipedia.org/wiki/Sunrise#Angle)

~~~
JudgeWapner
but it's also ~6 minutes _ahead_ of where we see it due to the time it takes
the light to get there. I wonder which effect wins?

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akeck
Slightly off topic, but one of the weapons I fear the most is a non-visible
spectrum anti-personnel laser.

~~~
nine_k
Bullets are already close to that: invisible, long-range, and shot from very
compact, inexpensive weapons, compared to lasers.

~~~
akeck
The thing that scares me is the silence.

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jimbob45
_See how we’re hurtling toward lasers that can stop hypersonic missiles._

Sounds like Raytheon is taking the page about concept cars from the car
industry and talking about totally conceptual products like they've already
shipped.

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gnode
I don't see why such lasers would require high power. Couldn't an array of
smaller lasers be used instead? It seems to me this would also counteract
blooming and add redundancy. If using microwave / radio radiation instead, a
phased array would allow the system to be instantly and multiply targetable.

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ohiovr
Weapons designers will then try to form ablative surfaces that can withstand
any practical level of bombardment.

~~~
ChuckMcM
Adds weight and limits range.

~~~
nostrademons
For a ballistic or hypersonic missile you need it anyway, to radiate away
atmospheric heating.

The challenge with an ABM laser weapon system is generating enough power on-
target that it's not just a rounding error for the energy that needs to be
dissipated anyway. A quick back-of-the-envelope physics calculation indicates
that'll be hard. An 80kg warhead is moving at about 5000 m/s upon re-entry and
has a kinetic energy of about 1 GJ. I dunno what fraction of that kinetic
energy is converted into thermal energy upon re-entry; for manned spacecraft
it's "almost all of it" because they need to go subsonic for parachutes to
deploy, but for ballistic missiles, let's guess 1/1000th for ease of math, or
1 MJ. Current laser weapons systems have a range of about 1mi (and the range
of lasers is heavily limited by atmospheric considerations - atmospheric
refraction will reduce your accuracy, while heating of water vapor, dust, and
air can sap the energy). That's about 1/3 of a second on target, so the power
output needed is about 3 MW. Current laser weapon systems like the AN/SEQ-3
have a power output of about 30 kW. This needs to scale up by a factor of 100
under conservative assumptions.

Like the article said, the solution to many of these issues is to put the
lasers in space and intercept missiles in the boost phase. Then they're moving
slower, you're targeting volatile fuel & oxidizer instead of heat shields, and
you don't have atmospheric losses to worry about. You do have the issue of how
to loft a giant laser, capacitor, and energy source into orbit, though, and
how to protect them up there when a conflict starts.

~~~
ChuckMcM
This is a good point, the weak spot is that the missile designer "knows" where
the extra energy is coming from (friction with the air). Once you add a laser,
the energy can come from "any" angle (within some limits of course).

Think of it this way, the shuttle could not dissipate massive energy on the
'top' because re-entry involved air over the bottom.

As for power rating, the Boeing High Energy Lasers were demonstrating
effective missile defense in 2017[1], they were ramping up their power levels
pretty quickly.

I see the biggest impact early on being fleet defense against hyper-sonic
anti-ship missiles rather than ABM defense. Basically a CWIS replacement since
it doesn't help to lose your $10B aircraft carrier to a $100M missile.

[1] [https://www.boeing.com/defense/missile-defense/directed-
ener...](https://www.boeing.com/defense/missile-defense/directed-
energy/index.page)

~~~
nostrademons
Warheads spin on re-entry anyway, so laser energy directed at any point other
than the centerline (which is pretty hard to hit) will get dissipated and
spread across the whole warhead.

I think the biggest impact is actually against low-tech threats: swarms of
fast attack suicide boats, or 1960s-era cruise missiles that have ended up on
the black market. There's a big cost advantage to being able to take these out
with a quick 30kW pulse rather than a million-dollar missile, particularly
since the threat itself probably cost less than a million dollars.

In a great-power conflict (where "great-power" is rapidly expanding to include
private multinational corporations) the U.S. military is fucked anyway, but
then, so is the opposing power. Perhaps that's the best we can hope for,
because it's a pretty strong incentive not to start great-power conflicts in
the first place.

~~~
Lev1a
> In a great-power conflict [...] the U.S. military is fucked anyway, but
> then, so is the opposing power. Perhaps that's the best we can hope for,
> because it's a pretty strong incentive not to start great-power conflicts in
> the first place.

Yes. That is indeed the concept of a (nuclear) deterrent.

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angel_j
Great, so maybe one attack vector is defended, and that of 2nd-rate States
trying to lob 80 year old technology.

Missile defense has been in development for decades, and it never works. By
the time it does, missiles will look like cross-bow bolts on the warfare menu.

Military spending is the elephant in the economy.

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nitwit005
Isn't there going to be a pretty short list of targets that are more valuable
than the missiles themselves? I can see an aircraft carrier making sense, but
it feels like there are cheaper ways to blow up most other targets.

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PaulHoule
The main trouble with ground-based is clouds, that is what makes you go
airborne.

I could picture planes in the air 24-7 circling around vulnerable points, or
being dispatched on warning. Either way it would be expensive but would be
awesome.

~~~
mustacheemperor
>I could picture planes in the air 24-7 circling around vulnerable points

The US previously spent a few billion and 16 years on that exact idea as part
of the SDI, before canceling it a few years after the first working tests
because, to quote the Defense Secretary,

>I don't know anybody at the Department of Defense who thinks that this
program should, or would, ever be operationally deployed. The reality is that
you would need a laser something like 20 to 30 times more powerful...there's
nobody in uniform that I know who believes that this is a workable concept[0]

If the laser power was a problem, maybe Raytheon's tech will make the concept
more plausible. The wikipedia article says there's been some additional
experimentation mounting lasers on UAVs since the program was cancelled.

[0][https://en.wikipedia.org/wiki/Boeing_YAL-1](https://en.wikipedia.org/wiki/Boeing_YAL-1)

~~~
PaulHoule
There is terminal defense against ICBMs and there is midcourse defense against
hypersonics.

The ballistic warhead has little more to do than absorb the heat of reentry in
the terminal phase. The energy to destroy it would be a good fraction of the
energy that was in the rocket to begin with.

The hypersonic weapon on the other hand has to have sensors, effectors, and be
unable to complete it's mission after receiving less beamed energy.

The airborne laser was killed not because it wasn't powerful enough (for some
mission) but because the chemical laser it used was dangerous, expensive and
otherwise impractical. The air force knew the army was developing modular
fiber lasers so they decided to wait for that before building another
platform, which could also be used against everything from drones to small
ballistic missiles.

Hypersonic is just the cherry on top.

The alternative for interception hypersonics would be the nuclear-tipped ABMs
of old, since the maneuvering capability of hypersonics defeats "hit-to-kill".

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abdulhaq
As a civilian, when we get lasers to take out everyone in the weapons
business, I'll celebrate.

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Taniwha
Doesn't this just turn a targeted nuclear strike on a city into a dirty bomb
strike on a city?

~~~
Taniwha
Or possibly a chemical attack using vaporized plutonium

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thefounder
So this means we should expect big wars in Europe again? Without nukes the
deterrent will no longer exist.

~~~
jsty
You'd also have to consider the likelihood of one getting through your laser
defences, and what the cost of protecting your country with these would be.

If you have a 99% chance of stopping a missile, but your adversary has tens or
hundreds of thousands of missiles to fire at you, those aren't great odds.

Plus in a pinch, modern societies could probably come up with some fairly
hideous deterrent weapons that didn't require missile delivery.

~~~
b_tterc_p
That’s a good point, and in fact probability of error doesn’t even need to
come into play. If you can destroy 10 missiles per second with probability 1,
then you have a 0% chance of stopping 11 missiles at once. Massive
simplifications here but the point stands. Scale matters.

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fmakunbound
> takes bigger optical mirrors with coatings that withstand such a massive
> amount of energy

What of missiles coated the same way?

