Air Force Turns 747 Into Holster for Giant Laser (washingtonpost.com)
Point this baby at the ground... http://washingtonpost.com/wp-dyn/articles/A27248-2001Jul20.html -- -- ____________________________________________________________________ Nature and Nature's laws lay hid in night: God said, "Let Tesla be", and all was light. B.A. Behrend The Armadillo Group ,::////;::-. James Choate Austin, Tx /:'///// ``::>/|/ ravage@ssz.com www.ssz.com .', |||| `/( e\ 512-451-7087 -====~~mm-'`-```-mm --'- --------------------------------------------------------------------
At 09:14 AM 7/22/2001 -0500, you wrote:
Point this baby at the ground...
http://washingtonpost.com/wp-dyn/articles/A27248-2001Jul20.html
I wonder what the destructive mechanism is for this system? Heat by radiant absorption seems an obvious but impractical method. If it is, then as the article mentions there may be some inexpensive and practical countermeasures to such a system, such as making the exterior of the missile body into a multi-faceted mirror able to reflect both IR and radar energy (although doing the same for the nose cone might prove more difficult due to aerodynamics). steve
On Sun, 22 Jul 2001, Steve Schear wrote:
I wonder what the destructive mechanism is for this system?
There was an article in IEEE Spectrum last year (I think) on one of the systems. The main failure mechanism is weakening of the aeroshell and due to increased loading the missile comes apart. The same sort of thing happened in Desert Storm with some of the Scuds that used plywood sheeting instead of aluminum. It's one of the primary factors of their high failure rate.
Heat by radiant absorption seems an obvious but impractical method.
It's the one they use primarily.
If it is, then as the article mentions there may be some inexpensive and practical countermeasures to such a system, such as making the exterior of the missile body into a multi-faceted mirror able to reflect both IR and radar energy (although doing the same for the nose cone might prove more difficult due to aerodynamics).
While reflecting the thermal energy is a good idea, doing the same for radar isn't since it allows more conventional systems to be used to track the missile, contrary to the goal of delivering large quantities time on target. Of course reflecting the IR allows one to use a 'dual component' system whereby another missile homes in on the reflected laser (standard IR designator sort of stuff). Another aspect is to beam the exhaust. By creating hydrodynamic shockwaves in the exhaust cone it should become possible to cause the engine to come apart due to back-pressure or simply creating ancillary thrust vectors and causing the guidance system to mis-calculate. Thrust attack like this must take place very early in the launch or at each stage seperation. You've probably got no more than 30-60 seconds out of a 30 minute flight (for a ICBM that isn't sub launched, then you've got single/double stage and about 15 minutes max). While the current systems won't do it, it should even be possible with high power short pulse width systems to heat the air in front of the rocket to cause turbulence. -- ____________________________________________________________________ Nature and Nature's laws lay hid in night: God said, "Let Tesla be", and all was light. B.A. Behrend The Armadillo Group ,::////;::-. James Choate Austin, Tx /:'///// ``::>/|/ ravage@ssz.com www.ssz.com .', |||| `/( e\ 512-451-7087 -====~~mm-'`-```-mm --'- --------------------------------------------------------------------
On Sun, 22 Jul 2001, Steve Schear wrote:
I wonder what the destructive mechanism is for this system?
There was an article in IEEE Spectrum last year (I think) on one of the systems. The main failure mechanism is weakening of the aeroshell and due to increased loading the missile comes apart.
Many missile (propellants) are pressurized; weakening a bit of the skin will cause it to burst.
First post - I hope it goes out
Here's a link to the first story I saw about this
technology in TechnologyReview.
http://www.technologyreview.com/magazine/jul01/freedmanall.asp
--- David Honig
On Sun, 22 Jul 2001, Steve Schear wrote:
I wonder what the destructive mechanism is for this system?
There was an article in IEEE Spectrum last year (I think) on one of the systems. The main failure mechanism is weakening of the aeroshell and due to increased loading the missile comes apart.
Many missile (propellants) are pressurized; weakening a bit of the skin will cause it to burst.
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At 01:28 AM 7/23/2001 -0500, you wrote:
On Sun, 22 Jul 2001, Steve Schear wrote:
I wonder what the destructive mechanism is for this system?
There was an article in IEEE Spectrum last year (I think) on one of the systems. The main failure mechanism is weakening of the aeroshell and due to increased loading the missile comes apart. The same sort of thing happened in Desert Storm with some of the Scuds that used plywood sheeting instead of aluminum. It's one of the primary factors of their high failure rate.
Heat by radiant absorption seems an obvious but impractical method.
It's the one they use primarily.
Only because the rocket exterior has not been "stealthed" via high reflectivity and faceting. steve
On Mon, 23 Jul 2001, Steve Schear wrote:
It's the one they use primarily.
Only because the rocket exterior has not been "stealthed" via high reflectivity and faceting.
Maybe. But even mirrors can be burned through by a laser. And then we've got weight issues that this would entail. It's not like they've got a lot of overhead for the job. I suspect that faceting wouldn't be any more effective than a smoothly round body form, it could have aerodynamic effects as well (ie sharp corners at the facet edges - and yes they could be rounded - now you're moving back toward a round rocket planform). -- ____________________________________________________________________ Nature and Nature's laws lay hid in night: God said, "Let Tesla be", and all was light. B.A. Behrend The Armadillo Group ,::////;::-. James Choate Austin, Tx /:'///// ``::>/|/ ravage@ssz.com www.ssz.com .', |||| `/( e\ 512-451-7087 -====~~mm-'`-```-mm --'- --------------------------------------------------------------------
At 06:05 PM 7/23/2001 -0500, Jim Choate wrote:
On Mon, 23 Jul 2001, Steve Schear wrote:
It's the one they use primarily.
Only because the rocket exterior has not been "stealthed" via high reflectivity and faceting.
Maybe. But even mirrors can be burned through by a laser. And then we've got weight issues that this would entail. It's not like they've got a lot of overhead for the job. I suspect that faceting wouldn't be any more effective than a smoothly round body form, it could have aerodynamic effects as well (ie sharp corners at the facet edges - and yes they could be rounded - now you're moving back toward a round rocket planform).
Ahhh but faceted exterior would deny the adversary less a visual or radar cross section to acquire and track (yeah I know about the tail plume). steve
On Mon, 23 Jul 2001, Jim Choate wrote:
Maybe. But even mirrors can be burned through by a laser. And then we've
Jim, why are you trying so hard to make a complete fool out of yourself, in a public forum? A chemical laser needs active optics to track your remote target. What do you think that optics is made from, unobtainium? Do you understand basic laws of optics? I recommend purchasing a 15 W laser (and a pair of matching protection goggles), and then use it to ignite a match from a close distance, and then over a few km, preferably during summer in your native Texas. You could target the beam towards a projection wall, and watch it with a pair of binoculars. It will be quite instructive.
got weight issues that this would entail. It's not like they've got a lot of overhead for the job. I suspect that faceting wouldn't be any more effective than a smoothly round body form, it could have aerodynamic effects as well (ie sharp corners at the facet edges - and yes they could be rounded - now you're moving back toward a round rocket planform).
High albedo coating of the missile is *cheap*. Powerful lasers are that not, especially if you need to have several of them online in an area. -- Eugen* Leitl <a href="http://www.lrz.de/~ui22204/">leitl</a> ______________________________________________________________ ICBMTO : N48 10'07'' E011 33'53'' http://www.lrz.de/~ui22204 57F9CFD3: ED90 0433 EB74 E4A9 537F CFF5 86E7 629B 57F9 CFD3
On Tue, 24 Jul 2001, Eugene Leitl wrote:
On Mon, 23 Jul 2001, Jim Choate wrote:
Maybe. But even mirrors can be burned through by a laser. And then we've
Jim, why are you trying so hard to make a complete fool out of yourself, in a public forum?
A chemical laser needs active optics to track your remote target. What do you think that optics is made from, unobtainium? Do you understand basic laws of optics? I recommend purchasing a 15 W laser (and a pair of matching protection goggles), and then use it to ignite a match from a close distance, and then over a few km, preferably during summer in your native Texas. You could target the beam towards a projection wall, and watch it with a pair of binoculars. It will be quite instructive.
The optics used for focusing are NOT mirrors, they are (hopefully) transparent at the frequency under use. A mirror on the other hand is required to be OPAQUE with respect to transmission, we want full, 100%, reflectivity. That means that every photon that hits that mirror interacts, loses some energy, and gets re-emitted. I have a half dozen lasers, thank you very much. -- ____________________________________________________________________ Nature and Nature's laws lay hid in night: God said, "Let Tesla be", and all was light. B.A. Behrend The Armadillo Group ,::////;::-. James Choate Austin, Tx /:'///// ``::>/|/ ravage@ssz.com www.ssz.com .', |||| `/( e\ 512-451-7087 -====~~mm-'`-```-mm --'- --------------------------------------------------------------------
At 04:43 PM 7/24/2001 -0500, Jim Choate wrote:
On Tue, 24 Jul 2001, Eugene Leitl wrote:
On Mon, 23 Jul 2001, Jim Choate wrote:
Maybe. But even mirrors can be burned through by a laser. And then we've
Jim, why are you trying so hard to make a complete fool out of yourself, in a public forum?
A chemical laser needs active optics to track your remote target. What do you think that optics is made from, unobtainium? Do you understand basic laws of optics? I recommend purchasing a 15 W laser (and a pair of matching protection goggles), and then use it to ignite a match from a close distance, and then over a few km, preferably during summer in your native Texas. You could target the beam towards a projection wall, and watch it with a pair of binoculars. It will be quite instructive.
The optics used for focusing are NOT mirrors, they are (hopefully) transparent at the frequency under use. A mirror on the other hand is required to be OPAQUE with respect to transmission, we want full, 100%, reflectivity. That means that every photon that hits that mirror interacts, loses some energy, and gets re-emitted.
The optics used for focusing are probably mirrors, one fully reflective and probably backed by piezo actuators to controllably distort for focus and adjust for atmospheric distortions, the other mostly reflecting (to keep the lasing process going) to "leak" the lethal beam. steve
On Tue, 24 Jul 2001, Jim Choate wrote:
The optics used for focusing are NOT mirrors, they are (hopefully)
Okay, a have a chemical laser, something which burns tons of fuel (deuterium/fluorine) in a second in a resonant cavity. It is hence a not very small cavity. The wavelength is IR, several microns. This is high-power optics with a giant aperture (because, you don't want your optics to suffer the fate of your target, and because the resonant cavity itself is huge). Lenses don't like giant fluxes, either. Even a ruby laser pulse can break optics, or the rod, if it has a blemish. Lenses are *HEAVY*. Lenses are not flexible, so you can't use them for tracking. Lenses don't do very well when we're talking about few um IR. So what that leaves you with is an active mirror optics.
transparent at the frequency under use. A mirror on the other hand is required to be OPAQUE with respect to transmission, we want full, 100%, reflectivity. That means that every photon that hits that mirror interacts, loses some energy, and gets re-emitted.
Jim, I fear that bullet accident you had took a chunk out of one of your frontal lobes. Or at least lead to a hemorrhage to a lesion in that area. Have you ever had a MRI screen done? I'm serious.
I have a half dozen lasers, thank you very much.
-- Eugen* Leitl <a href="http://www.lrz.de/~ui22204/">leitl</a> ______________________________________________________________ ICBMTO : N48 10'07'' E011 33'53'' http://www.lrz.de/~ui22204 57F9CFD3: ED90 0433 EB74 E4A9 537F CFF5 86E7 629B 57F9 CFD3
On Sun, 22 Jul 2001, Jim Choate wrote:
Point this baby at the ground...
http://washingtonpost.com/wp-dyn/articles/A27248-2001Jul20.html
Seen some of this before. It's sexy, especially if one thinks of the propaganda value: it's basically "death from above". Sampo Syreeni, aka decoy, mailto:decoy@iki.fi, gsm: +358-50-5756111 student/math+cs/helsinki university, http://www.iki.fi/~decoy/front
On Mon, 23 Jul 2001, Sampo Syreeni wrote:
Seen some of this before. It's sexy, especially if one thinks of the propaganda value: it's basically "death from above".
You're saying it, "propaganda value". Missiles are only vulnerable during boost phase, while they still have fuel onboard. Chemical lasers are expensive, have limited operation time, are cranky, and laser tracking is a nightmare. Mirroring the surface of the missile is a cheap countermeasure, requiring orders of magnitude larger critical flux and thus driving hardware costs at the other end. You need serious energy flux and tracking precision to terminate a warhead. LEO hardware might be able to do it, but not without much, much, much lower launch costs. -- Eugen* Leitl <a href="http://www.lrz.de/~ui22204/">leitl</a> ______________________________________________________________ ICBMTO : N48 10'07'' E011 33'53'' http://www.lrz.de/~ui22204 57F9CFD3: ED90 0433 EB74 E4A9 537F CFF5 86E7 629B 57F9 CFD3
On Mon, 23 Jul 2001, Eugene Leitl wrote:
You're saying it, "propaganda value". Missiles are only vulnerable during boost phase, while they still have fuel onboard.
Bull. Missiles are vulnerable to various assaults during their entire flight. The aerodynamic forces during boost and terminal flight operations, vacuum effects (rupture a fuel tank and watch that baby gyrate).
You need serious energy flux and tracking precision to terminate a warhead.
Which has been demonstrated to be extant since the mid-80's when they shot the first satellite down with a high altitude fighter. -- ____________________________________________________________________ Nature and Nature's laws lay hid in night: God said, "Let Tesla be", and all was light. B.A. Behrend The Armadillo Group ,::////;::-. James Choate Austin, Tx /:'///// ``::>/|/ ravage@ssz.com www.ssz.com .', |||| `/( e\ 512-451-7087 -====~~mm-'`-```-mm --'- --------------------------------------------------------------------
On Mon, 23 Jul 2001, Jim Choate wrote:
Bull. Missiles are vulnerable to various assaults during their entire flight. The aerodynamic forces during boost and terminal flight
My comment was limited to radiant energy weapons. As to those, the critical vulnerability exists during launch and boost phase. The target is slow, bright, large, has fuel on board and a nonarmored hull, which (as other posters observed) can be weakened with enough flux. The warhead in transit is fast, small, silent, and very, very hard to hit critically (well, it is designed to withstand reentry and nuclear antimissile near-hits), especially if it has a high-albedo coating, and if it is accompanied by a cloud of decoys. Either radiant energy weapon or kinetic kill, you're on the losing side here.
operations, vacuum effects (rupture a fuel tank and watch that baby gyrate).
True, but irrelevant.
You need serious energy flux and tracking precision to terminate a warhead.
Which has been demonstrated to be extant since the mid-80's when they shot the first satellite down with a high altitude fighter.
A missile in boost phase is not a satellite. A cloud of decoys is not a satellite. An armored warhead is not a satellite. The problem assymetry makes star wars a very expensive proposition. Using airborne hardware instead of LEO is a good move, but it falls orders of magnitude short of the target. The demos are just that: demos. Given that a limited strike is best conducted with remotely operated civilian aircraft, or plain old UPS, star wars seems like effect of industrial lobby.
On Mon, 23 Jul 2001, Eugene Leitl wrote:
My comment was limited to radiant energy weapons.
Even that's not sufficient since lasers have been demonstrated for mid-course assaults as well.
As to those, the critical vulnerability exists during launch and boost phase. The target is slow, bright, large, has fuel on board and a nonarmored hull, which (as other posters observed) can be weakened with enough flux.
All it really takes is to get it cocked a tad off senter and aerodynamic forces will take it apart, irrespective of hull weakness.
The warhead in transit is fast, small, silent, and very, very hard to hit critically (well, it is designed to withstand reentry and nuclear antimissile near-hits), especially if it has a high-albedo coating, and if it is accompanied by a cloud of decoys. Either radiant energy weapon or kinetic kill, you're on the losing side here.
They've certainly managed to kill enough of them in tests starting as far back as the ASAT fighters from the 80's. The reality is that quite a lot of research goes on in attacking the warheads while in the mid-course phase. It's also worth mentioning that in general the individual (assuming MRV) warheads don't usually seperate until after mid-flight. This means a not-so-small target.
operations, vacuum effects (rupture a fuel tank and watch that baby gyrate).
True, but irrelevant.
Actually not, if you strike the tanks (they are typically filled with Nitrogen to both provide strength, ala a plastic coke bottle with the top on and off, and to help move fuel to the engines. Approximately half the flight occurs in this phase.
Which has been demonstrated to be extant since the mid-80's when they shot the first satellite down with a high altitude fighter.
A missile in boost phase is not a satellite. A cloud of decoys is not a satellite. An armored warhead is not a satellite.
The satellite used was specifically chosen to mimic the characteristics of a re-entry vehicle. All I can say is google and 'anti-satellite aircraft'. -- ____________________________________________________________________ Nature and Nature's laws lay hid in night: God said, "Let Tesla be", and all was light. B.A. Behrend The Armadillo Group ,::////;::-. James Choate Austin, Tx /:'///// ``::>/|/ ravage@ssz.com www.ssz.com .', |||| `/( e\ 512-451-7087 -====~~mm-'`-```-mm --'- --------------------------------------------------------------------
On Sun, Jul 22, 2001 at 09:14:56AM -0500, Jim Choate wrote:
Point this baby at the ground...
http://washingtonpost.com/wp-dyn/articles/A27248-2001Jul20.html
That will result only in a very broken 747. -- ___ ___ . . ___ \ / |\ |\ \ _\_ /__ |-\ |-\ \__
participants (7)
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D B -
David Honig -
Eugene Leitl -
Izaac -
Jim Choate -
Sampo Syreeni -
Steve Schear