Future Warfare

[Tower75]

That bit was stupid. As above, fuel, and speed. The shuttle is already in space, travelling at, I dunno, space-speeds, and a missile from Earth, shot from a shoulder-module, catches up with it in space? Yeah okay.

The distance of space is too vast for a man-fired missile to hot a shuttle travelling in space.

 

[Mirannan]

The problem wouldn't be the warhead but the fuel. Off the top of my head I think the problem would be producing a portable missile that has sufficient fuel to reach Low Earth Orbit. Current man portable ground to air missiles are designed for normal flight altitudes so maybe will go up to 10-20km (actually I think most man portable system only have about a 5km range). Low Earth Orbit is from 160km to 2,000km so that is ten plus times farther and would require much more fuel. If we come up with a much more efficient fuel then maybe, otherwise I doubt it.

Can't be done, especially if you want velocity matching as well. (This is worth following up; the Virgin Galactic craft will reach orbital height but that is NOT the same as achieving orbit.)

It can't be done because chemical fuels can't hold enough energy. The only two methods I can think of to get a reasonable payload into a man-portable device are some sort of nuclear isomer energy storage (google "hafnium bomb") or an out-and-out nuclear rocket. Or an antimatter-powered rocket.

The nuclear rocket might be possible as an outgrowth of small-unit fusion tech such as Polywell or focus fusion; the developers of the latter even mention the possibility of changing the geometry a bit and turning a fusion reactor into a fusion rocket. It's going to take a LOT of development, though.

It's also worth mentioning that such a device is going to need a chemical first stage. Why? Well, consider what's going to happen to the hapless soldier who is selected to fire the DPF fusion-powered missile - and, as a consequence, is bathed in the exhaust from said device. Fusion plasma is bad for the health.

Something like this is probably only going to be portable by someone wearing a powered exoskeleton at least.

 

[Ray McCarthy]

fusion reactor into a fusion rocket.

Won't be less than enormous. Unless you have Magic.

To take out even very LEO craft (80Km and higher) you'd need at minimum a very large truck launched missile with a 2nd truck with tracking and encrypted guidance.
Even civilian aircraft at cruising altitude can't be taken by manpack, only at take off and landing. It's truck mounted missile that's used.

An ICBM can be easily adapted to strike spaceships. Actually Sputnik was launched on a modified ICBM.

 

[Spiegal]

I can imagine truck mounted missile launchers being the most likely avenue for an anti space weapon. If there is added mobility it could make it difficult for spaceships attempting to land as opposed to using silos which could possibly be detected from orbit.

They could even be used as area denial in orbit if it released a field of shrapnel on a collision path with the vessel. This could also remove the need for the missile to catch up with the target and reduce the needed fuel for an intercept.

I was also thinking of how MANPADS are best used on take off or landing, if a Dropship is barreling through the atmosphere it will be quite a show in infrared spectrums. This along with the comms blackout during reentry could be the best bet for taking out a ship while its sensors are compromised.

 

[Devon.Q.Ly]

space would be awesome for projectile weapons, no wind resistance and squat gravity. You're bullet would have a massive effective range. You'd have to replace the primer though, pretty sure it wouldn't go off without any oxygen. A railgun or coilgun probably the most likely propellants.
But i think the more likely scenario would be a move to energy weapons, a weak supply line is what devastates many armies. Getting bullets from planet X to your front line may take forever, so that's why I think energy weapons would be favoured.

 

[Vertigo]

I might be wrong here but I think cordite and also gunpowder have their oxygen already in the mixture supplied, in the case of gunpowder the saltpetre (potassium nitrate) so I guess they should work in a vacuum.

 

[Spiegal]

I might be wrong here but I think cordite and also gunpowder have their oxygen already in the mixture supplied, in the case of gunpowder the saltpetre (potassium nitrate) so I guess they should work in a vacuum.

I'm fairly sure you are right about the oxidiser in the gunpowder mix, however conventional firearms would have a real tough time working in space. If you were in sunlight for example, the lubricant on the gun will be sublimating and drifting away as gas on one side and frozen solid on the dark side of the weapon. Your best bet would be a dry lubricant such as graphite powder to allow free movement without the logistics of a vacuum and high temperature stable 'wet' lubricant.

I really believe that Railguns and Coilguns would be the order of the day, no moving parts to lubricate, no gunpowder to lug around or be a hazardous material onboard and the ability to cause ridiculous amounts of damage with a relatively small projectile.

With regards to the MANPADS idea I think people missed the point about it being used while a dropship or other vessel is approaching the surface, similar to how they are used now on takeoff or landing.

 

[Vertigo]

You are probably right about lubricants etc. but and adapted conventional (explosive) firearm would probably still be fine for a hand weapon at least until you could get an appropriate battery pack for a small rail gun to a reasonably portable size.

Certainly man portable launchers would probably continue to be practical for landing and taking off, but, to be fair, you did originally say "... would be effective against spacecraft in low earth orbit."

 

[Ray McCarthy]

A small rail gun might fit on a low loader. Of course a fantasy one that uses some principle we don't know and back pack fusion generator might do in SF.

Current rail guns can fire projectiles at hypersonic speed and for naval use may bring back the battleship era. Probably they will solve the problem of them only lasting about 4 or 5 shots!
You need a reasonable length of rail to get appreciable speed. It's hard to see how a hand held one would have much more punch than an air gun. Regular cartridge / bullet / shell weapons will indeed work in space / vacuum with suitable easy adaptation.

 

[Vertigo]

That was my thought. For a hand held weapon, we still don't really have anything on the horizon that will beat what we have today! Oh improved versions of course, but no new technology hand held weapons... which is actually quite interesting.

On the subject of handheld weapons, before someone comes up with a laser gun - which might be made hand held in the future. Would a hand held laser gun be very effective. I imagine you wouldn't be able to hold the trigger and just sweep around with it as it would likely get overheated and drain it's power pack excessively fast if used in this way. So just how effective would such a weapon be? My feeling is that, if hand held, it would have to be a very small 'calibre' 'beam' and therefore unless it hit a vital organ it would do very little damage, with no internal expansion as in a conventional bullet, and it would probably cauterise itself instantly. In fact I suspect even hitting a vital organ it might not do a great deal of damage.

 

[Ray McCarthy]

You can make a dangerous enough laser gun today. Of course the light is monochromatic so a suitable filter protects the eyes.

Aluminium foil protect the rest of you from a low power but otherwise deadly device. A more powerful laser weapon needs more specialised counter measures and the power supply is an issue before it's too big to use on the shoulder.

Mirror on copper plated (to spread heat) lightweight ceramic armour.

In the atmosphere a suitable smoke canister is protection. It's more effective in space, but not as much as large rail gun, shell or missile.

If a space ship had alumina coating, with synthetic diamond coating (diamond is excellent heat conductor to spread heat) and various reflective layers it could be made laser proof. Also magnetically controlled plasma is a shield against IR and visible lasers, though possibly not UV lasers.

 

[Vertigo]

Only dangerous to the eyes though. I may be wrong, but I believe we are a long way from making a portable laser that is dangerous to the body (as you say, easy enough to protect your eyes). My point is that, even without all the protective measures you talk about, the wound would be very small and self cauterising; and therefore useless unless it hits a vital organ and in a vital place. I would say there are few targets on the human body where a small laser would do serious damage; the brain and the heart and even then I'm not sure it would be serious damage.

 

[JoanDrake]

Only dangerous to the eyes though. I may be wrong, but I believe we are a long way from making a portable laser that is dangerous to the body (as you say, easy enough to protect your eyes). My point is that, even without all the protective measures you talk about, the wound would be very small and self cauterising; and therefore useless unless it hits a vital organ and in a vital place. I would say there are few targets on the human body where a small laser would do serious damage; the brain and the heart and even then I'm not sure it would be serious damage.

Several holes might be problematic though, even if they were very small. Perhaps if it fired in bursts of extremely short duration, say a hundred thousandth second long shots in a tenth of a second and have it so the shots targeting bounces around just a tiny bit, so each one makes a separate tiny hole but it's very close to the last one. That way you do some real damage but still only have the beam on for a very short time. OTOH I don't think pulsing fast is a fundamental design limitation in lasers but it may be, given my understanding of how they work.


Also, remember the holes are all the way through. I don't think the spinal cord likes any holes in it, cauterized or not.


And then there's the idea that they don't have to use visible light. In fact, if they can use gamma rays you have a whole plethora of other problems that might cause, but I don't think they can and even if they could that would require LOTS more energy, yes?


Maybe good for a story though. Soldiers being burned dead by lasers before they even know they're being fired on

 

[Michael Colton]

In the atmosphere a suitable smoke canister is protection. It's more effective in space, but not as much as large rail gun, shell or missile.

I need to read the whole thread to really join in the conversation fully, but just a sidenote: I have always found railguns and futuristic missiles the most interesting when reading fiction. I do not have a problem with the others by any means, but there is something about railguns that give a tangible feel to me that plasma and lasers do not.

 

[Ray McCarthy]

You can pulse lasers down to femto seconds. But continuous operation is more likely for a smaller weapon. The very large high power lasers are limited to a few seconds by the ability of the optics to handle the power.
Some synthetic crystal medium power lasers only seem to have a continuous beam, it's actually rapid pulses.
There are certainly lasers today that could be handheld (if you are an idiot) and lethal if applied to a person not wearing protective clothing, They are under $500 (green usually) and used in computer controlled cutting / milling / etching table top sized machines.
I nearly bought one for engraving and other applications. I have the SW and files to drive the system (About $3500 for budget table top CNC ready for your PC), but laser to retrofit to existing CNC mill is available)

Nd:YAG lasers are used in manufacturing for engraving, etching, or marking a variety of metals and plastics. They are extensively used in manufacturing for cutting and welding steel, semiconductors and various alloys. For automotive applications (cutting and welding steel) the power levels are typically 1–5 kW.

See Nd:YAG laser
Certainly possible to power for 10 minutes off 4 x 12V batteries + electronics in a very heavy back pack and small / light enough to hand hold.

Incredibly there is no licence requirement for ownership. Seriously more dangerous than the battery powered models used by idiots to flash at aircraft. Any expert Electronic Engineer could make a back-pack PSU.
It's doubtful any such weapon is ever going to be as effective as a rifle, machine gun etc due to limitations of power. In last 65 years we have only reduced to about 1/3rd the weight vs capacity of suitable battery packs (i.e. Lithium powered car vs 1949 NiCd battery packs used in Military Radio).
The really powerful lasers that can destroy a tank, satellite or missile use a generator set about size of a container and are single use chemical lasers. Firing uses up the chemicals, transferred from supply to waste tanks. The limit on power seems to be the optics as even a very small percentage loss of 100kW is going to cook the optics. Most of the energy of the Megawatt range Chemical laser is from the toxic chemicals. The vast amount of electricity needed is for cooling and pumping. Even 0.1% loss in optics could be 2kW! The loss could be higher.
Chemical laser
You won't as easily buy one of these as the CNC lasers. Your local recycling centre won't accept the waste chemicals from firing.

Despite the performance advantages of chemical lasers, the Department of Defence stopped all development of chemical laser systems with the termination of the Airborne Laser Test bed in 2012. The desire for a "renewable" power source, i.e. not having to supply unusual chemicals like fluorine, deuterium, basic hydrogen-peroxide, or iodine, led the DoD to push for electrically pumped lasers such as diode pumped alkali lasers

Currently using arrays of solid state lasers are under development and are nearly at Chemical laser power levels. But it's more a case of research because they can.

Current system is 1/10th to 1/50th power of abandoned Chemical lasers

Laser Weapon System

I don't think anyone seriously thinks lasers are a weapon of the future. Military has already done it and largely abandoned it. See also

Soviet laser pistol

Also see
Directed-energy weapon

Rail gun tests have proved that with development it's more devastating than laser. They just have to solve the problem of the short life of the rail gun
Railgun

Currently only American nuclear powered vessels may have enough electricity generation capacity. They need a lot of power. You also need a minimum length of rail, those to facts mitigate against any man portable weapon. Even if you have a magical Fusion power Backpack (A scary thought) the "rail" part is going to need at least a truck. Using it on your spacecraft implies a very large craft, even so every action has a reaction, so you can even use it as propulsion. Even if you don't want to!

Plasma weapons are only very short range and in a vacuum. Probably inherently useless. Like trying to throw balls of steam, expands very rapidly.

 

[Michael Colton]

Currently only American nuclear powered vessels may have enough electricity generation capacity. They need a lot of power. You also need a minimum length of rail, those to facts mitigate against any man portable weapon. Even if you have a magical Fusion power Backpack (A scary thought) the "rail" part is going to need at least a truck. Using it on your spacecraft implies a very large craft, even so every action has a reaction, so you can even use it as propulsion. Even if you don't want to!

This paragraph is all sorts of amusing. Let us combine the elements: fusion power strapped to the back of a truck that is propelled backwards when firing the railgun. Someone should make a webcomic strip about this.

 

[Ray McCarthy]

I can write the text and descriptions if you can do the artwork!
I may have a suitable story

 

[Vertigo]

Good post Ray, confirms more or less what I suspected though I hadn't realised that lasers of that level of power had come down that low in cost.

Joan, you are quite correct that the spinal cord would be another vulnerability. However I still feel that a non fatal hit would not do enough damage militarily. An incapacitated wounded soldier is generally considered to have more impact on the enemy's effectiveness than a kill as they will then hamper their unit until evacuated. I suspect lasers simply wouldn't deliver in that sense.

 

[Spiegal]

Good post Ray, confirms more or less what I suspected though I hadn't realised that lasers of that level of power had come down that low in cost.

Joan, you are quite correct that the spinal cord would be another vulnerability. However I still feel that a non fatal hit would not do enough damage militarily. An incapacitated wounded soldier is generally considered to have more impact on the enemy's effectiveness than a kill as they will then hamper their unit until evacuated. I suspect lasers simply wouldn't deliver in that sense.

I think the potential in a laser weapon against a human target would actually be in lowering the laser below the maximum yield.

If you lower the energy then you could control the effect of the impact. A setting on too low power would cause a nasty burn but if you could create a laser pulse that would cause a steam explosion or heat damage to surrounding tissue, then you are going to have targets with completely debilitating injuries.

 

[Ray McCarthy]

Having actually used SLR, Bren (7.62mm version), Lee Enfield .303* and having an understanding of human nature, lasers and plasma, my money is on people still using bullets and missiles in 400 years time. Unfortunately.

(*I enjoy archery more, easier on shoulder than .303 but sore on fingers and arms. The Bren though slowly creeps forwards.)

Laser sight/range finder, goggles with head up display, steerable "bullets" and multi-function/ammunition type weapons seems more likely than Laser or Plasma pistols or rifles.

Watch: DARPA shows off first successful test of STEERABLE bullet
Shades of "Rodger Rabbit"!

Do read the "fantasy themed" Comments

Also
Precision-guided munition - Wikipedia, the free encyclopedia