5 ms·

Anti-Orbit Laser Submarines (2017)

64 points by EA-3167 2y ago

master_crab 2y ago
I don’t think I have ever spent so long trying to understand the physics of destroying an invading alien spaceship.
- ginkgotree 2y ago
  Isn't it fun to noodle on? lol
- nopelynopington 2y ago
  Independence day had the right idea. Just inflict windows ME on them via a convenient day-18250 vulnerability
ginkgotree 2y ago
Cool idea. Atmospheric attenuation (regardless even if you lase at "transmissible" freqs), would be a major issue. Additionally, beam steering and focusing from 1000km+, and accounting (essentially a variable continuously changing integration) for a high variability in index of refraction would make it possible without a closed-loop feedback of on target strike. Rough ballparks, I mean, the beam power density required would likely far exceed the thermal dissipation rate of any heat pipe, etc, tech I am officially aware of. Space warfare is super fun tho. However, this is a very outdated idea. If anyone like noodling on this stuff, they should DM me. There are far better ideas... unofficially.
- airstrike 2y ago
  FYI there's no way to DM you on HN unless you leave some contact info on your profile, which may or may not be in the form of a puzzle.
- sandworm101 2y ago
  >> Atmospheric attenuation You start with the adaptive optics used in many telescopes. For whatever angular resolution an earth-based telescope can accomplish, that same tech can probably also focus a laser beam to a similar degree. (Adaptive optics largely started from laser weapon programs, only later being used for astronomy.) https://en.wikipedia.org/wiki/Boeing_YAL-1 https://en.wikipedia.org/wiki/Boeing_YAL-1
- nopelynopington 2y ago
  Share with the class. I'm not sliding into anyone's DMs, even for space warfare
curtisszmania 2y ago
[dead]
Full_Clark 2y ago
The supercavitating supersonic submarine is a nice endpoint for the evasion discussion but I can't help thinking about the wake that would leave. Yes it can depart the firing area quickly but if one wanted to find it again for counterfire, surely the point where the absurd wake turbulence ends is a suitable search datum. Presumably an opponent with capable spaceships can spare the power required for scans along these principles: https://www.sciencedirect.com/science/article/abs/pii/S0924271621001593 https://www.sciencedirect.com/science/article/abs/pii/S09242...
- deleted 2y ago
  [deleted]
InDubioProRubio 2y ago
Dear god, they firing a laser again.. activate the water pumps.. its all steam outside.. the dread.. the horror.. now we dive, and its all surface steam. Oh, the fish-manity. They burned away one layer of glycol shield plating. Horrific. Oh, they use x-ray lasers- but the platform that comes up to fire, is hardened, automated, a shooter, that returns to the depths.
- nopelynopington 2y ago
  > Oh, the fish-manity I'm glad I wasn't drinking anything when I read this because it would be coming out my nose about now
  - amy214 2y ago
    It's not a joke, in the '60s they considered Lazer Submarines but the technology wasn't scalable at that time, a lazer weapon usually would be backpack size. At the time the US Navy began developing a secret project which is Lazer Dolphins. The Soviet got wind of this and worried about the Lazer Arms Race Gap, so they begin to develop Lazer Sharks. Of course that isn't the end of the whole Lazer arms race, in modern times there have been efforts to use genetic technology to resurrect ancient organisms to mount Lazers upon. For example, China is developing Lazer Raptors currently, and Russia has announced several wonder weapons including a nuclear rocket engine ICBM, a submarine-sized fusion bomb drone torpedo, and Lazer Mammoths.
teknopaul 2y ago
[flagged]
- actionfromafar 2y ago
  It's hard to imagine a total block of access to orbit. More expensive and inconvenient, yes. You can always go for polar orbits, and higher orbits. (Or lower orbits - your satellite will deorbit in a few months/years because of atmospheric drag, but the same goes for any junk there.
  - yummypaint 2y ago
    It makes a difference where the junk is. As you say low orbits clean themselves up slowly, but geosynchronous Kessler syndrome could last thousands of years, and geostationary orbits are pretty essential.
    - actionfromafar 2y ago
      Yes, if the geostationary orbits were inaccessible, you would require maybe tens or hundreds of satellites launched in a ring to achieve the same the same result. :-/ On the other hand geostationary orbits or so far out it's maybe harder to achieve a dense enough junk field out there to matter? I have no intuition about such scales...
- NoNotTheGreeks 2y ago
  What do you mean by de-democratizing technology? Off-hand the only democratic part of technological advancement of which i can think is open source. Pretty much everything else is private development.
tiku 2y ago
I've always wondered why we don't have remote controlled zeppelins yet. Seems like the perfect platform for drones. Use hydrogen inside the zeppelin and for a fuel cell module.
- squarefoot 2y ago
  Probably too slow, easy to detect and shoot down.
MrBuddyCasino 2y ago
Interesting thought experiment. Some questions: - couldn’t the submarine have some sort of extendable trunk to avoid the loss of laser energy in water? Basically a much longer periscope? - the RASER principle seems to be much easier to deploy from space, where large dishes are simple to deploy, potentially offsetting reactor cooling disadvantages, and mitigate the protective effect of water? - are 10-20 Meters of water really enough to protect against kinetic weapons?
- fooblaster 2y ago
  I think this article undersells the size of the antenna needed to focus a powerful radio source into a distant target.
- nopelynopington 2y ago
  > couldn’t the submarine have some sort of extendable trunk to avoid the loss of laser energy in water? Basically a much longer periscope? I'm put in mind of the mirror on a stick in Saving Private Ryan
ranger207 2y ago
There's a similar concept in the Battletech universe. The Lowyfur, a Wyrm-class submersible SDS, evaded capture for 5 years after the liberation of Terra, continuing to prowl the oceans and inflict Blakist terror. https://www.sarna.net/wiki/Wyrm_SDS_Submersible_Fortress https://www.sarna.net/wiki/Wyrm_SDS_Submersible_Fortress
perihelions 2y ago
The article doesn't make any mention of stealth. I think stealth would be a key factor in any serious future space war. On general physics principles, it's not difficult to make a space object with close to zero emissions in a specified direction. The inverse-square law is a helpful ally. Active (i.e. radar or lidar) have rapidly diminishing returns: their signal powers scale as distance^{-4}—doubly inverse-square. I'm not sure what response can be invented against a dark space object that shoots dark stealth warheads that detonate in the upper atmosphere.
- datadrivenangel 2y ago
  A dark space object can be seen when it passes between the observer and stars or other objects, so you need to match the spectrum behind you, which makes it a much harder problem! Being very cold is good for long range stealth, but in low orbit the speeds are high enough that it doesn't help against a savvy adversary.
  - perihelions 2y ago
    - "A dark space object can be seen when it passes between the observer and stars or other objects," Those are called transits. They're extraordinarily rare for any single given object. Moreover, there are quadrillions of natural objects transiting stars as a baseline noise rate, which you'd be hard-pressed to distinguish a spacecraft from. One hiding among quadrillions. Even if you were very lucky and both observed, and identified, a spacecraft transiting a star, you've instantly lost it. You would need multiple transits in close succession to recover an orbit (and predict its future positions), something which will statistically never happen.
    - datadrivenangel 2y ago
      If you have a number of anti-orbit laser submarines, I suspect a global network of observer stations that are passively looking for transits that don't have a known source is within your budget
      - 2y ago
nopelynopington 2y ago
HN, where one story is about hypothetical submarine spaceship laser battles, and the next is about usb-ps2 mouse port adapters, and you want to read them both.

64 points by EA-3167 2y ago

master_crab 2y ago

I don’t think I have ever spent so long trying to understand the physics of destroying an invading alien spaceship.

ginkgotree 2y ago
Isn't it fun to noodle on? lol
nopelynopington 2y ago
Independence day had the right idea. Just inflict windows ME on them via a convenient day-18250 vulnerability

ginkgotree 2y ago

Cool idea. Atmospheric attenuation (regardless even if you lase at "transmissible" freqs), would be a major issue. Additionally, beam steering and focusing from 1000km+, and accounting (essentially a variable continuously changing integration) for a high variability in index of refraction would make it possible without a closed-loop feedback of on target strike. Rough ballparks, I mean, the beam power density required would likely far exceed the thermal dissipation rate of any heat pipe, etc, tech I am officially aware of. Space warfare is super fun tho. However, this is a very outdated idea. If anyone like noodling on this stuff, they should DM me. There are far better ideas... unofficially.

airstrike 2y ago
FYI there's no way to DM you on HN unless you leave some contact info on your profile, which may or may not be in the form of a puzzle.
sandworm101 2y ago
>> Atmospheric attenuation You start with the adaptive optics used in many telescopes. For whatever angular resolution an earth-based telescope can accomplish, that same tech can probably also focus a laser beam to a similar degree. (Adaptive optics largely started from laser weapon programs, only later being used for astronomy.) https://en.wikipedia.org/wiki/Boeing_YAL-1 https://en.wikipedia.org/wiki/Boeing_YAL-1
nopelynopington 2y ago
Share with the class. I'm not sliding into anyone's DMs, even for space warfare

curtisszmania 2y ago

[dead]

Full_Clark 2y ago

The supercavitating supersonic submarine is a nice endpoint for the evasion discussion but I can't help thinking about the wake that would leave. Yes it can depart the firing area quickly but if one wanted to find it again for counterfire, surely the point where the absurd wake turbulence ends is a suitable search datum. Presumably an opponent with capable spaceships can spare the power required for scans along these principles: https://www.sciencedirect.com/science/article/abs/pii/S0924271621001593 https://www.sciencedirect.com/science/article/abs/pii/S09242...

deleted 2y ago
[deleted]

InDubioProRubio 2y ago

Dear god, they firing a laser again.. activate the water pumps.. its all steam outside.. the dread.. the horror.. now we dive, and its all surface steam. Oh, the fish-manity. They burned away one layer of glycol shield plating. Horrific. Oh, they use x-ray lasers- but the platform that comes up to fire, is hardened, automated, a shooter, that returns to the depths.

nopelynopington 2y ago
> Oh, the fish-manity I'm glad I wasn't drinking anything when I read this because it would be coming out my nose about now
- amy214 2y ago
  It's not a joke, in the '60s they considered Lazer Submarines but the technology wasn't scalable at that time, a lazer weapon usually would be backpack size. At the time the US Navy began developing a secret project which is Lazer Dolphins. The Soviet got wind of this and worried about the Lazer Arms Race Gap, so they begin to develop Lazer Sharks. Of course that isn't the end of the whole Lazer arms race, in modern times there have been efforts to use genetic technology to resurrect ancient organisms to mount Lazers upon. For example, China is developing Lazer Raptors currently, and Russia has announced several wonder weapons including a nuclear rocket engine ICBM, a submarine-sized fusion bomb drone torpedo, and Lazer Mammoths.

teknopaul 2y ago

[flagged]

actionfromafar 2y ago
It's hard to imagine a total block of access to orbit. More expensive and inconvenient, yes. You can always go for polar orbits, and higher orbits. (Or lower orbits - your satellite will deorbit in a few months/years because of atmospheric drag, but the same goes for any junk there.
- yummypaint 2y ago
  It makes a difference where the junk is. As you say low orbits clean themselves up slowly, but geosynchronous Kessler syndrome could last thousands of years, and geostationary orbits are pretty essential.
  - actionfromafar 2y ago
    Yes, if the geostationary orbits were inaccessible, you would require maybe tens or hundreds of satellites launched in a ring to achieve the same the same result. :-/ On the other hand geostationary orbits or so far out it's maybe harder to achieve a dense enough junk field out there to matter? I have no intuition about such scales...
NoNotTheGreeks 2y ago
What do you mean by de-democratizing technology? Off-hand the only democratic part of technological advancement of which i can think is open source. Pretty much everything else is private development.

tiku 2y ago

I've always wondered why we don't have remote controlled zeppelins yet. Seems like the perfect platform for drones. Use hydrogen inside the zeppelin and for a fuel cell module.

squarefoot 2y ago
Probably too slow, easy to detect and shoot down.

MrBuddyCasino 2y ago

Interesting thought experiment. Some questions: - couldn’t the submarine have some sort of extendable trunk to avoid the loss of laser energy in water? Basically a much longer periscope? - the RASER principle seems to be much easier to deploy from space, where large dishes are simple to deploy, potentially offsetting reactor cooling disadvantages, and mitigate the protective effect of water? - are 10-20 Meters of water really enough to protect against kinetic weapons?

fooblaster 2y ago
I think this article undersells the size of the antenna needed to focus a powerful radio source into a distant target.
nopelynopington 2y ago
> couldn’t the submarine have some sort of extendable trunk to avoid the loss of laser energy in water? Basically a much longer periscope? I'm put in mind of the mirror on a stick in Saving Private Ryan

ranger207 2y ago

There's a similar concept in the Battletech universe. The Lowyfur, a Wyrm-class submersible SDS, evaded capture for 5 years after the liberation of Terra, continuing to prowl the oceans and inflict Blakist terror. https://www.sarna.net/wiki/Wyrm_SDS_Submersible_Fortress https://www.sarna.net/wiki/Wyrm_SDS_Submersible_Fortress

perihelions 2y ago

The article doesn't make any mention of stealth. I think stealth would be a key factor in any serious future space war. On general physics principles, it's not difficult to make a space object with close to zero emissions in a specified direction. The inverse-square law is a helpful ally. Active (i.e. radar or lidar) have rapidly diminishing returns: their signal powers scale as distance^{-4}—doubly inverse-square. I'm not sure what response can be invented against a dark space object that shoots dark stealth warheads that detonate in the upper atmosphere.

datadrivenangel 2y ago
A dark space object can be seen when it passes between the observer and stars or other objects, so you need to match the spectrum behind you, which makes it a much harder problem! Being very cold is good for long range stealth, but in low orbit the speeds are high enough that it doesn't help against a savvy adversary.
- perihelions 2y ago
  - "A dark space object can be seen when it passes between the observer and stars or other objects," Those are called transits. They're extraordinarily rare for any single given object. Moreover, there are quadrillions of natural objects transiting stars as a baseline noise rate, which you'd be hard-pressed to distinguish a spacecraft from. One hiding among quadrillions. Even if you were very lucky and both observed, and identified, a spacecraft transiting a star, you've instantly lost it. You would need multiple transits in close succession to recover an orbit (and predict its future positions), something which will statistically never happen.
  - datadrivenangel 2y ago
    If you have a number of anti-orbit laser submarines, I suspect a global network of observer stations that are passively looking for transits that don't have a known source is within your budget
    - 2y ago

nopelynopington 2y ago

HN, where one story is about hypothetical submarine spaceship laser battles, and the next is about usb-ps2 mouse port adapters, and you want to read them both.