Anti missile defense

[Rune175]

I hope this is not a repost, but I couldn't find the topic in the Search function.

 

The US have for a long time been trying to develop a missile defense system, to defend themselves from nuclear attacks etc. From my understanding this project has failed so far.

 

From what I have read about the project the system contains multiple anti air missile launching sites around the US and in other areas as well. When an enemy missile is within range of the anti air missile sites, multiple counter missiles will be fired agains the hostile missile and destroy it.

 

I was thinking of another way, probably to ambitious - and some of you might have som cons against it too.

 

I know that scientist have been searching in different energy weapons, eg. laser weapons.

 

What if, several sattelites were launched around the US in geo synchric orbit containing the following equipment: A large mirror (or solar collector if you will) and a huge buffer to store the energy absorbed.

Now, the sattelite would, of course, need a weapon to shoot down through the atmosphere and destroy or disable the hostile missile. A laser beam in this case would probably be ineffective when beaming it through the atmosphere as the light would spread and the beam would be weak when entering the atmosphere. Of course in vacuum space this weapon would be much more effective, but the difficult part is that fact that the beam must penetrate the atmosphere, which would make it very weak, as mentioned above.

If instead an x-ray laser weapon was used, this would make the beam much more effective, even when entering the atmosphere, and with enough energy (the huge buffer) the beam could disable the hostile missile.

 

The sattelite would be controled from the earth, and only repairs or upgrades would cause the need for manpower. In that way the sattelite would be "cheap" once built. It wouldn't need an energy source from earth, instead it would use the energy from the sun to recharge.

 

I have used the US only as an example as they are already trying to develop an anti missile defense system. This idea could apply for other countries as well.

 

I'm looking forward for your input or, if you really must, your cons.

[insane_alien]

the starwars program was essentially this. and it would not need to penetrate the atmosphere so conventional laser technology could be used.

 

the reason it does not need to penetrate the atmosphere is that ICBM's (the most likely missile attack) spend most of there time out of the atmosphere. they are on a suborbital trajectory and will havean apogee some 200-300 km above the surface of earth. the problem is getting a powerful, reliable and light laser to fit the bill. pick any two of those and we could do it. but for the thing to be feasible it needs to be all three.

[5614]

The laser anti-missile program that I had heard of, and has been succesfully tested, is this one (Tactical High Energy Laser):

http://en.wikipedia.org/wiki/Nautilus_laser

it has shot down many rockets, artillery shells and mortar rounds. Although apparently it has now been discontinued, not sure why, although there also are calls to renew it.

 

At the bottom of that link (See Also section) there are some links to other similar laser systems.

 

As for your suggestion: a satellite-based solar panel would be more effective than an Earth-based one in the sense that more light falls it on (the sunlight doesn't get filtered out by the atmosphere). However it is still a relatively slow method for collecting energy, to be useful it would really need to have very big solar panels (or mirrors), which would then be very vulnerable to space debris and solar winds etc. And then I think it is about 2/3 of light (the energy from the satellite) coming from the sun does not reach the Earth due to the atmosphere.

 

I wouldn't deem it impossible, there is quite probably research going on along your lines right now, but there are several immediate problems that need to be addressed, as I outlined above.

[Rune175]

the problem is getting a powerful, reliable and light laser to fit the bill. pick any two of those and we could do it. but for the thing to be feasible it needs to be all three.

 

If the laser is beamed only in vacuum space, I believe it would be possible to create a beam powerfull enough to burn through the hole of the hostile missile. The good thing about a laser weapon in space is the fact that the energy in the beam won't decrease in power, as it would if fired against the atmosphere. The only limit to the power of the laser, roughly said, is the size of the buffer/battery.

For the thing to be reliable is, I believe, a question about developing the proper technology and target system in order for the weapon to function at near perfection. This I believe has caused some problems, and still does, when developing a reliable overall system.

I'm not sure what you mean with the last one, that a light laser is required, perhaps you would like to explain that a little more.

 

I'm sure the current technology required to design a lasersystem, like the one discussed, is available, it is only a matter of time before it can, perhaps, become a reality.

 

5614:

 

Hadn't really given any thought regarding the problem with large mirrors and space debris and solar winds, thanks for pointing that out.

In order to protect a satelite from inteferences like you mentioned, what would it require? Could it be realistic to believe that if the satelite was armored properly it could resists debris and solar winds?

 

I appreciate the answers, great to finally have found a serious forum where people know what they are talking about!

[Cap'n Refsmmat]

The trouble is that current lasers that are powerful enough to take down missiles require massive amounts of chemicals to provide their energy, and can only fire a limited number of shots before the chemicals are exhausted. You can't refuel a satellite, and the chemical tanks required are big.

 

A highly efficient laser that could fit on a satellite would have to be developed.

[5614]

5614:

 

Hadn't really given any thought regarding the problem with large mirrors and space debris and solar winds, thanks for pointing that out.

In order to protect a satelite from inteferences like you mentioned, what would it require? Could it be realistic to believe that if the satelite was armored properly it could resists debris and solar winds?

To gather enough energy to power a laser the area of the satellite would need to be quite big, however the International Space Station is also quite big and that has not had any major incidents. Mind, if something hit the edge of a space station it would have a different effect to if it slammed through a massive mirror!

 

As for how to protect a satellite, I don't really know. A little bit of searching I did only gave me some articles regarding space debris / junk, but didn't talk about satellite protection.

 

Part of the problem is that space debris moves as very high speeds, I can't really think of a way to protect something, only that you would have to construct it so that it could withstand a collision. One of the articles does talk about how improbably and very rare collisions are, but with a project like this you should probably plan for it!

 

http://www.space.com/scienceastronomy/astronomy/leonids_satellites_991112.html

 

http://news.nationalgeographic.com/news/2006/01/0119_060119_space_junk.html

 

http://www.guardian.co.uk/science/2008/feb/24/spaceexplorationspacejunk?gusrc=rss&feed=science

[Rune175]

Probably a bad question..

 

What if you used X-rays instead of laser, would it be easier to disable/destroy a missile, or do you need a laser?

[insane_alien]

it would be easier to use a normal laser. xray lasers are less efficient and less reliable.

[5614]

X-rays require a lot more energy to produce.

 

Also I don't think an x-ray "laser" could be made, because the energies involved are too high for electrons to produce by losing energy (an electron with that much energy would just escape the atom it is bonded to).

 

If you ever go for an x-ray (a medical one) there's a whole load of heavy, energy consuming, machinery behind it. In nearly all (all?) cases there's an electron accelerator, which then collides with a metal target, producing the x-rays. Having a whole electron accelerator up in space isn't very practical (size, energy consumption, maintenance etc.) and also I'm not sure if focusing the x-ray beam is possible. In medical applications you can focus the beam very accurately, but that is at a close distance range.

 

Lasers are good for shooting down missiles etc. because they produce a very fine energy beam that doesn't spread out much. An x-ray source (which can't be laser based) would probably spread out too much to be of any use, not that it is even practical ignoring this!

[Rune175]

Thanks alot guys for the good answers!

[Cap'n Refsmmat]

http://en.wikipedia.org/wiki/European_x-ray_free_electron_laser

[5614]

Also I don't think an x-ray "laser" could be made, because the energies involved are too high for electrons to produce by losing energy (an electron with that much energy would just escape the atom it is bonded to).

After seeing IA's post before mine, I Googled x-ray lasers a little and it seems they do exist.

 

They don't work in the same way as a normal laser (from what I've read), and I think this is because, as I reasoned in the quote above, the energies involved would be too high. But you can seemingly produce x-rays which have laser-like properties.

 

For example: http://en.wikipedia.org/wiki/Free_electron_laser

 

 

 

[edit] doh Cap'n! You and your 1min head start!

[John Cuthber]

(I'm using the US and Russia as examples of protagonists here- it doesn't really matter who the parties are)

If the US built a laser powered by a big mirror I think one of 2 things would happen, the Russians would throw rocks at it and destroy it (a mirror that big in space would need to be very fragile otherwise it wouldn't be light enough to launch)

or

A small meteorite would destroy if and the US would blame the Russians.

 

A "nuclear powered x ray laser in space" might just be possible and was put forward as part of the "star wars" project.

[dragonstar57]

correct me if I am Wrong but the laser would loose no power the farer away the target is from the weapon in space

so would a simple 20 MW pulsed nitrogen laser be enough to destroy a missile?

[Cap'n Refsmmat]

Laser beams still spread in space, so distant targets would be harder to kill.

 

You might be interested in this:

 

http://www.scientificamerican.com/article.cfm?id=laser-downs-uavs

[Moontanman]

The USA has lasers that work quite well in defending against incoming missiles. the Navy recently tested a laser and it worked well against small aircraft. Lasers are becoming better and better, new technology allows for lasers to be fired from ground vehicles not much larger than a Humvee and to knock down incoming artillery rounds. New powerful solid state lasers have opened up the possibility of airplanes as small as fighter jets using lasers against each other and incoming missile attack. Of course there is the almost outdated now laser defense system mounted in a 747 aircraft meant to shoot down ground to ground missiles in the launch stage. I'm not sure I would discount anti missile laser technology advancing to the point of actually shooting down incoming ICBMs in the near future. There have been some real advancements since Reagan initiated Star Wars.... Nothing I would be the farm on in a nuclear attack yet but it's not total bullshit now like it was in the 80's.

 

opps, sorry cap'n, i missed your link... yeah what he said....

Edited August 10, 2010 by Moontanman

[JohnB]

I trust nobody from the US would be concerned by the large number of Russian, Chinese, North Korean and other weapon sats that would then proliferate the skies?

 

Not being mean, but is there anywhere that the US hasn't wanted to put a weapons platform?

[Horza2002]

Interesting topic here, however there is one slight problem. There is a treaty in force that prohibits any sort of weapon in orbit or space which the US and all other space faring nations aree part of. So while in principle you could use satalites to shoot down enemy missililes, practically the satalites would not be allowed in orbit though. Ground based lazers (or sea based as Moontanman says) have proven to be effective.

[dragonstar57]

it wouldn't be a weapon it would be a defense mechanistic. it wouldn't be designed for offense purposes.

but a missile defense would be a terrifying technology because whats stooping nuclear war now is basically the old cold war policy MAD

take that out of the picture by one country able to defend itself from nukes and shoot havoc would break loose.

 

and if a 20 MW pulsed nitrogen laser was focussed to a very small beam diameter wouldn't it counteract the spreading of the beam

[Moontanman]

I have serious doubts about any of the major powers launching a nuclear attack, we all know it would be bad for us all. The real danger is small countries who think they are sent from God to conquer the world using nukes to try and show they have power. Lasers or other anti missile tech could and should be developed to defend against rogue states that have no care for the effects of nuclear attack on them selves or the rest of the world.

[Mr Skeptic]

it wouldn't be a weapon it would be a defense mechanistic. it wouldn't be designed for offense purposes.

 

Defense (and transport too) are a sort of indirect weapon. They increase the ability to fight.

[DJBruce]

but a missile defense would be a terrifying technology because whats stooping nuclear war now is basically the old cold war policy MAD

take that out of the picture by one country able to defend itself from nukes and shoot havoc would break loose.

 

The doctrine of mutually assured destruction in its original form has been long gone. Regan's strategic defense initiative and the fall of the Soviet Union slept the end of mutually assured destruction. Currently aside from Russia the United States has 32 times as many nuclear warheads as the third country. So the mutual part of that destruction is anything but assured. That being said I would venture to say that no major country will ever launch a nuclear attack on another country. They realize that a nuclear act would provide no benefits, and would cause a massive economic and diplomatic crisis.