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Sci-Fi Science

DARPA Developing Defensive Plasma Shield 318

Posted by Zonk
from the now-we-just-need-blasters dept.
galactic_grub writes "According to an article at New Scientist, DARPA is developing a plasma shield that would allow troops to stun and disorientate enemies. The system will use a technology known as dynamic pulse detonation (DPD), which involves producing a ball of plasma with an intense laser pulse, and then a supersonic shockwave within the plasma using another pulse. The result is a gigantic flash and a loud bang in a the air. 'The company has also pitched a portable laser rifle, which would be lethal, to the US Army. It would weigh about fifteen kilograms, would have a range of more than a mile, and could have numerous advantages over existing rifles - better accuracy and the ability to hit a moving target at the speed of light.'"
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DARPA Developing Defensive Plasma Shield

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  • by Dan East (318230) on Friday April 27, 2007 @07:42PM (#18907093) Homepage Journal
    I thought lasers made inefficient weapons because they cauterize the wounds they create.

    Dan East
  • Also, FTA... (Score:3, Interesting)

    by SixFactor (1052912) on Friday April 27, 2007 @07:58PM (#18907281) Journal
    ... is a way to change the laser rifle's intensity, and thus, its lethality. Yeah, I envision settings for STUN and KILL. Shark mount optional.

  • Wow. Just Wow. (Score:2, Interesting)

    by KnowledgeKeeper (1026242) on Friday April 27, 2007 @08:00PM (#18907309)
    Are United States expecting some kind of alien foothold situation? :) Airborne lasers, laser rifles, Star Wars satellites, exoskeletons, wearable computers, hand-launched intercontinental ballistic missiles, atomic and neutron bombs, personal shields made of liquids, harmless skin burners...

    I don't know about others, but this sounds pretty much like stuff we could read about in comics and watch in cartoons. Wouldn't it be funny if somewhere in a small well-guarded room there's a top-notch team of physicists that does research on new weapons by reading comics?
  • Re:Laser rifle (Score:3, Interesting)

    by brit74 (831798) on Friday April 27, 2007 @08:07PM (#18907379)
    Not to mention the fact that it will be that much harder to locate the sniper. At least a gun produces a muzzle-flash and sound.
  • Re:Laser rifle (Score:4, Interesting)

    by einhverfr (238914) <chris.travers@NoSPAm.gmail.com> on Friday April 27, 2007 @08:12PM (#18907429) Homepage Journal
    A laser of this size is likely to provide a flash of light and sound (not stunning as in the other technology). This is due to the laser ionizing the air it travels through (creating the same sort of plasma as the other part of the story). I would expect the path to be very visible to anyone looking in the right direction at the right moment.

    33kg is not a light weapon, and not something a sniper could simply hold up for precision firing with his hands. You would probably need a tripod, etc. So in the end you are looking at a not-very-sniper-like weapon.
  • by Un pobre guey (593801) on Friday April 27, 2007 @08:22PM (#18907513) Homepage
    To say nothing of the mayhem they cause due to some of the beam reflecting off the target, or missing it partly or completely. As I recall, this was deemed a major drawback to the airborne laser discussed here about a year ago. Also, the lasers require very large amount of input energy in order to generate a militarily useful beam. This means consumables, added weight, transportation, firing prep, detectability by the enemy, etc. This sounds like Pentagon bullshit to me, disinformation designed to frighten and fake out naive Third World military.
  • Re:Laser rifle (Score:5, Interesting)

    by steveha (103154) on Friday April 27, 2007 @08:25PM (#18907543) Homepage
    A sniper's job will become a whole lot easier... unless you want to get into the fact that the majority of a sniper's job is about getting in and then hopefully back out.

    Actually, this would be a win from that standpoint as well. Current sniper bullets are always supersonic, and thus there is a loud *CRACK* sound that helps indicate the location of the sniper. The laser beam would be silent.

    (If you are interested in snipers, you ought to read the book Marine Sniper [amazon.com], a biography of Carlos Hathcock [wikipedia.org]. Hathcock commented that a sniper usually gets one free shot, because no one is expecting the shot, and surprised people don't do a good job of figuring out where the shot came from; if the sniper fires a second shot, all the people in the area will start looking in the correct direction, because this time they are expecting something. So he figured it was better to get close enough to get a guaranteed one-shot kill; even though he would be closer, he would be much harder to find than if he had to take a second shot.)

    Imagine a sniper killing someone, and the only sound is the body falling over. Kind of creepy. The sniper might be able to kill the person without other people in the area even noticing!

    On the other hand, assuming a high-tech enemy, it might be possible to track the sniper by waste heat from the laser. If you are putting enough energy to kill out of a laser rifle, there will be nontrivial amounts of waste heat. So there might be a special "sniper model" battlefield laser weapon that contains the heat somehow (cartridges with compressed gases, and you use the expanding gas to cancel the waste heat?). Thus the sniper model would probably be the heaviest model.

    (Or perhaps the heaviest model would be the "squad automatic" laser, which could be fired many times rapidly...)

    Actually, a physics question: would there be a trail in the air, caused by the laser traveling through the air, that could be seen with some sort of vision enhancer goggles? Would the air molecules be ionized or something, and could that be used to track a sniper? If so, there would be a line drawn in the air pointing from the target straight back at the sniper. But I really have no idea if that is possible.

    steveha
  • by einhverfr (238914) <chris.travers@NoSPAm.gmail.com> on Friday April 27, 2007 @08:26PM (#18907553) Homepage Journal
    I noted that they could ionize the air with a non-lethal laser, and that they were suggesting that there might be non-lethal uses for the laser rifle. This might allow for a usage essentially essentially similar to a long-range version of a Taser.

    Basically, if you can ionize the air, you should have a conductive path. You could then send a high-voltage current down that path to incapacitate the person struck.
  • by shaitand (626655) on Friday April 27, 2007 @08:41PM (#18907687) Journal
    'I don't think any government would sell something like that to its citizens.'

    If governments wanted the people to have power (utlimately all power is derived from force) our rebel leader forefathers wouldn't have had to put the right to bear arms in the constitution. It exists precisely because power must be distributed and a disarmed citizenry only have power at the mercy of the government.

  • Re:Why the toys??? (Score:5, Interesting)

    by Cyberax (705495) on Friday April 27, 2007 @09:06PM (#18907927)
    AK-47 is obsoleted by AK-74 (which can use NATO ammo, BTW).

    Besides, accuracy at a great distance usually means nothing in city warfare. You almost never have ranges larger than 15-20 meters and AK-47 works great at these distances.
  • by ChrisMaple (607946) on Friday April 27, 2007 @09:34PM (#18908161)
    The high inherent accuracy of a laser means that if you can see 'em, you can kill 'em, first shot. This is a considerable advantage over current weapons in some situations. It's cheaper than a guided rocket, more accurate than a rifle. Possibly an ideal sniper/assassination weapon.
  • Re:Why the toys??? (Score:3, Interesting)

    by Waffle Iron (339739) on Friday April 27, 2007 @09:54PM (#18908333)
    It should have, but the people in charge convinced themselves that all the new toys invented in the intervening three decades would be silver bullets that would guarantee success. Their plan could have been written by the Underpants Gnomes:
    1. Cleanly knock out a few key sites with precision missiles.
    2. ???
    3. Stable Democracy!
  • Re:Why the toys??? (Score:5, Interesting)

    by funwithBSD (245349) on Friday April 27, 2007 @10:27PM (#18908527)
    Well, what you are really suggesting is that limited warfare does not work.

    Now the question is, when can we afford to use troops in the following situtations:

    1. Limited, humane "war". Oxymoron if their ever was one. Usually a failure, re: Vietnam.
    2. Geneva Convention "war". Works pretty well. Won in WWII and Korea.
    3. Total war. Pre-Convention war, no quarter given, civilization at risk. This is the long history of warfare and is true war.

    We are fighting an enemy using level 3 warfare while we remain at level 1.

    Level one is total stupidity. If that is all that was needed, you should have used other means like special forces hit and run. Don't send in long term troops unless you are ready to fight level 2.

    So go to level 2, or get out and wait for them to sack Washington.

    The scary thing for me is that as they get nukes, and they will one way or another, there is no way to do MAD style containment. They are not going to launch anything at us because they don't have the technology. So they sneak it in and detonate. Meanwhile, because we are so hung up on national boundries they don't really recognize, we don't know who to nuke.

    And we lost our ablity to fight as a civilization, like Rome, and just nuke the barbarians, period.

    I really don't see a way out until we shake out of our lethergy and understand that they want us all dead or converted to Islam. Anything else is al-Taqiyya.
  • by sohare (1032056) on Friday April 27, 2007 @11:46PM (#18909039)

    Do you have any facts to base up your assertions? Where are the surveys done by, say, neutral countries that suggest what you are saying is true? I'm assuming you are not being sarcastic.

    The US is notorious for supporting dictatorships and coup d'etas against democratically elected governments. Consider Honduras for instance, when the CIA supported a coup at the behest of the United Fruit and Standard Fruit companies. The US basically blockaded Fiji because they wouldn't allow for the testing of nuclear bombs near their shores. We've had heavy involvement in Iran for many years. Oh, and the support for Pol Pot?

    Anyone who says that envy drives the hatred of America is woefully ignorant of American foreign policy.

  • Re:Laser rifle (Score:2, Interesting)

    by FrankieBaby1986 (1035596) on Saturday April 28, 2007 @12:55AM (#18909373)
    Perhaps, this being an electronic gizmo, a decoy emitter(s) could be designed to be placed several hundred yards away, pointed in the same general direction to confuse people looking for such fire? Then it would "fire" at the same time as the weapon by remote. Eh, just speculating weird ideas. Beats me how to get around it.
  • Re:Why the toys??? (Score:3, Interesting)

    by bhiestand (157373) on Saturday April 28, 2007 @05:55AM (#18910331) Journal

    I've already done a combat tour and a second tour at a three-letter agency.
    Whew, you scared me. At first I thought you meant "four-letter agency", and I was scared shitless of the RIAA. Anyways, the M16A2 isn't terrible, but I do think we could do better, and I'd definitely be pissed if it was my only option. Did you see the weight of this "portable" laser rifle they're talking about, though? 15 kilos! Ever hump a 249 anywhere? They weigh about 7 bare, and you'd be hard-pressed to get one up to 10 kg with a rail, scope, heat shield, and talking power ranger doll.
  • by rantingkitten (938138) <kitten.mirrorshades@org> on Saturday April 28, 2007 @05:59AM (#18910333) Homepage
    But I'm reminded of John Titor here. You know, the guy who was posting on Usenet saying he was from the future? Bollocks, I'm sure, but he did have some interesting things to say, and one of them was something to the effect (I don't have the quote in front of me): "Pay attention when the government starts talking about non-lethal weapons to use against the enemy. When they start talking about that, the enemy they're talking about YOU. You don't really think they're going into hostile territory under RPG fire and jumping out of a helicopter with these 'non lethal' toys, do you?"

    And, well, I had to admit there was a point there. Maybe we should find it disturbing that so much research is being put into this kind of thing.
  • Re:Laser rifle (Score:3, Interesting)

    by salec (791463) on Saturday April 28, 2007 @07:40PM (#18914639)

    There have been theoretical weapon designs that let a laser ionize the path to the target and then send huge amounts of electricity through that path...

    Crossed my mind too, as several posters mentioned ionization of air along the beam: instead of relying on conversion of stored charge into current, then into light, to deliver destructive energy on target, just create an ionized channel and pour all the stored charge down on target. The show stopper is, of course, a possible "short circuit" discharge between channel and ground anywhere along the beam path, which, due to limited minimal angle between the beam and surface limits applicability to air-to-ground use.

    Vice versa, anti-sniper measure would be to keep possible target of assassination inside an isolated Faraday cage connected to powerful high voltage source - if high-power laser was deployed, assassin sniper would have been zapped through the channel his weapon created.

    However, there seems to be another, to me much more interesting possibility, completely out of military and destructive applications: the whole idea could be used to construct a laser induced conductive ionized air channel "infinite hight lightning rod", a system to harvest huge atmospheric electric energy in controlled manner, for our power needs!

    Or, perhaps those ionized channels could be used for very low current, very high voltage electrical power transmission without using metallic conductors at all. Perhaps we could even connect surface-to-orbit spacecrafts with ion engines to electric power grid using that technique, one "conducting channel" on each side of spacecraft, so that very little fuel mass is lifted.

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