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| Science & Technology |
| US working to develop ground-based laser weapon |
| 2006-05-03 |
| The Bush administration is seeking to develop a powerful ground-based laser weapon that would use beams of concentrated light to destroy enemy satellites in orbit. The largely secret project, parts of which have been made public through Air Force budget documents submitted to Congress in February, is part of a wide-ranging effort to develop space weapons, both defensive and offensive. No treaty or law forbids such work. The laser research was described by federal officials who would speak only on the condition of anonymity because of the topic's political sensitivity. The White House has recently sought to play down the issue of space arms, fearing it could become an election-year liability. Indeed, last week Republicans and Democrats on a House Armed Services subcommittee moved unanimously to cut research money for the project in the administration's budget for the 2007 fiscal year. While Republicans on the panel would not discuss their reasons for the action, Congressional aides said it reflected a bipartisan consensus for moving cautiously on space weaponry, a potentially controversial issue that has yet to be much debated. The full committee is expected to take up the budget issue today. The laser research is far more ambitious than a previous effort by the Clinton administration nearly a decade ago to test an antisatellite laser. It would take advantage of an optical technique that uses sensors, computers and flexible mirrors to counteract the atmospheric turbulence that seems to make stars twinkle. The weapon would essentially reverse that process, shooting focused beams of light upward with great clarity and force. Though futuristic and technically challenging, the laser work is relatively inexpensive by government standards — about $20 million in 2006, with planned increases to some $30 million by 2011 — partly because no weapons are as yet being built and partly because the work is being done at an existing base, an unclassified government observatory called Starfire in the New Mexico desert. In interviews, military officials defended the laser research as prudent, given the potential need for space arms to defend American satellites against attack in the years and decades ahead. "The White House wants us to do space defense," said a senior Pentagon official who oversees many space programs, including the laser effort. "We need that ability to protect our assets" in orbit. But some Congressional Democrats and other experts fault the research as potential fuel for an antisatellite arms race that could ultimately hurt this nation more than others because the United States relies so heavily on military satellites, which aid navigation, reconnaissance and attack warning. In a statement, Representative Loretta Sanchez, a California Democrat on the subcommittee who opposes the laser's development, thanked her Republican colleagues for agreeing to curb a program "with the potential to weaponize space." Theresa Hitchens, director of the Center for Defense Information, a private group in Washington that tracks military programs, said the subcommittee's action last week was a significant break with the administration. "It's really the first time you've seen the Republican-led Congress acknowledge that these issues require public scrutiny," she said. In a statement, the House panel, the Armed Services Subcommittee on Strategic Forces, made no reference to such policy disagreements but simply said that "none of the funds authorized for this program shall be used for the development of laser space technologies with antisatellite purposes." It is unclear whether the Republican-controlled Congress will sustain the subcommittee's proposed cut to the administration's request, even if the full House Armed Services Committee backs the reduction. The Air Force has pursued the secret research for several years but discussed it in new detail in its February budget request. The documents stated that for the 2007 fiscal year, starting in October, the research will seek to "demonstrate fully compensated laser propagation to low earth orbit satellites." The documents listed several potential uses of the laser research, the first being "antisatellite weapons." The overall goal of the research, the documents said, is to assess unique technologies for "high-energy laser weapons," in what engineers call a proof of concept. Previously, the laser work resided in a budget category that paid for a wide variety of space efforts, the documents said. But for the new fiscal year, it has moved under the heading "Advanced Weapons Technology." In interviews, Pentagon officials said the policy rationale for the arms research dated from a 1996 presidential directive in the Clinton administration that allows "countering, if necessary, space systems and services used for hostile purposes." In 1997, the American military fired a ground-based laser in New Mexico at an American spacecraft, calling it a test of satellite vulnerability. Federal experts said recently that the laser had had no capability to do atmospheric compensation and that the test had failed to do any damage. Little else happened until January 2001, when a commission led by Donald H. Rumsfeld, then the newly nominated defense secretary, warned that the American military faced a potential "Pearl Harbor" in space and called for a defensive arsenal of space weapons. The Starfire research is part of that effort. Federal officials and private experts said the antisatellite work drew on a body of unclassified advances that have made the Starfire researchers world-famous among astronomers. Their most important unclassified work centers on using small lasers to create artificial stars that act as beacons to guide the process of atmospheric compensation. When astronomers use the method, they aim a small laser at a point in the sky close to a target star or galaxy, and the concentrated light excites molecules of air (or, at higher altitudes, sodium atoms in the upper atmosphere) to glow brightly. Distortions in the image of the artificial star as it returns to Earth are measured continuously and used to deform the telescope's flexible mirror and rapidly correct for atmospheric turbulence. That sharpens images of both the artificial star and the astronomical target. Unclassified pictures of Starfire in action show a pencil-thin laser beam shooting up from its hilltop observatory into the night sky. The Starfire researchers are now investigating how to use guide stars and flexible mirrors in conjunction with powerful lasers that could flash their beams into space to knock out enemy satellites, according to federal officials and Air Force budget documents. "These are really smart folks who are optimistic about their technology," said the senior Pentagon official. "We want those kind of people on our team." But potential weapon applications, he added, if one day approved, "are out there years and years and years into the future." The research centers on Starfire's largest telescope, which Air Force budget documents call a "weapon-class beam director." Its main mirror, 11.5 feet in diameter, can gather in faint starlight or, working in the opposite direction, direct powerful beams of laser light skyward. Federal officials said Starfire's antisatellite work had grown out of one of the site's other military responsibilities: observing foreign satellites and assessing their potential threat to the United States. In 2000, the Air Force Research Laboratory, which runs Starfire, said the observatory's large telescope, by using adaptive optics, could distinguish objects in orbit the size of a basketball at a distance of 1,000 miles. Another backdrop to the antisatellite work is Starfire's use of telescopes, adaptive optics and weak lasers to track and illuminate satellites. It is considered a baby step toward developing a laser powerful enough to cripple spacecraft. Col. Gregory Vansuch, who oversees Starfire research for the Air Force Research Laboratory, said in an interview that the facility used weak lasers and the process of atmospheric compensation to illuminate satellites "all the time." Such tests, Colonel Vansuch emphasized, are always done with the written permission of the satellite's owner. He said that about once a month, Starfire conducted weeklong experiments that illuminate satellites up to 20 times. Though the House subcommittee recommended eliminating all financing next year for antisatellite laser research, it retained money for other laser development. Congressional aides said the proposed cut to the Air Force's $21.4 million budget request for such work would eliminate two of three areas of development, for a total reduction of $6.5 million. At least one public-interest group has seized on the issue. Last week, the Global Network Against Weapons and Nuclear Power in Space, based in Brunswick, Me., said that if Congress approved the antisatellite money, "the barrier to weapons in space will have been destroyed." |
| Posted by:Dan Darling |
| #18 How big did yawl grow that FEL Zen Man? My work was subcontracted by a company whose name rhymes with Huge Aircrash. There was talk of a 5 megawatt system the optics were going into. The primary optics consisted of a 12" diameter by 3" thick monocrystalline silicon blank worth about $10,000 each. Mind you, this was in the late 1980s, and only in the last few years have we economically grown 12" (1,000mm) silicon ingots. According to the visiting engineers, these blanks were hogged out of an 18" diameter ingot in order to eliminate any slip or dislocations in the crystal structure that are commonly found near an ingot's outer edge. The blanks were then coated with a thin film of slicon dioxide and returned to the manufacturing facility for diffraction patterning. At this point the blanks suddenly grew in value to $40,000 a piece. The light table these blanks were exposed on was supposed to be one of the most massive on earth in its time. Based on a multi-ton slab of solid granite, it had a beam path of several feet and resolved down to 1/20th of a wavelength in the ultra-volet end of the spectrum. To put things in perspective, a surface becomes a "mirror" when it is able to resolve better than 1/2 a wavelength of the highest frequency visible light (blue color) it is supposed to reflect. As you can see, at 5% resolution, that well beyond an entire order of magnitude better performance than your regular mirror. This resolution was necessary to ensure that the optic's reflectivity was maximized. Likewise, this was the reason for selecting a monocrystalline substrate. As the mirror's surface heated during exposure to the live E-beam, power would tend to dissippate more evenly through a monolithic (consistently spaced crystal) lattice. Ergo, that is why they shaved off so much of the blank's outer circumference, in the pursuit of eliminating any irregularities in the crystal's structure. Similarly, the reflective coating had to be incredibly consistent so as to avoid anomalies or discontinuities in surface heating which (despite the water cooling journals bored through the optic's backside) would result in hotspots able to cause (as the military likes to put it) "spontaneous catastrophic disassembly." #13 Probably not that big. Ionization trails, y'know. Actually, the FEL remains the laser of choice for ground based antisatellite DEWs (Directed Energy Weapons). Issues of tunability, scalability and stability are all optimal for such a system. The beauty of a FEL is that the beam can be circulated in an oscillator cavity and then pumped via "wigglers". These smaller magnets interact with an E-beam to stimulate the release of powerful synchrotron radiation that is tunable over a very wide range of millimeter waves to X-rays. Newer versions have a straight path single-pass system that submits the beam to an "undulator" (basically a long path wiggler) to obtain extremely powerful emission via SASE (Self Amplified Spontaneous Emission). For a great primer on FELs, go to: http://www.plasma.ernet.in/~beta/whatis.html |
| Posted by: Zenster 2006-05-03 21:36 |
| #17 I see your c4i and raise you c4i2tsr! |
| Posted by: DarthVader 2006-05-03 20:44 |
| #16 ya gotta start someplace to get to laser weapons that can take out artillery shells Already in test phase on these. |
| Posted by: lotp 2006-05-03 20:42 |
| #15 C4I==Command, Control, Communications, Computers, and Intelligence http://www.psycom.net/iwar.1.html |
| Posted by: Ptah 2006-05-03 17:58 |
| #14 The Soviets reportedly tested an anti-satellite laser way back in the early '80s. In addition, they did extensive work with explosively-powered lasers and particle beam weapons (you detonate an explosive in a chamber, the chamber walls absorb some part of the detonation energy and transfer it to a power convertor, which stored the energy in a capacitor, which can be used to fire the laser - the basic principle is similar to the idea for bomb-pumped x-ray lasers, but the firing platform is not destroyed in the resulting explosion and laser discharge). In addition, as I recall, there was much to-do about a Soviet radar installation that was thought to be either intended for anti-ballistic missile systems or anto-satellite systems or, at least according to one report, was actually a cover for a ground-to-space laser. LBNL has developed table-top particle beams using laser wakefield technology. This has some fairly obvious military implications and applications, potentially. It's even unclassified work. See Nature last year sometime. |
| Posted by: FOTSGreg 2006-05-03 17:44 |
| #13 Probably not that big. Ionization trails, y'know. |
| Posted by: mojo 2006-05-03 17:26 |
| #12 How big did yawl grow that FEL Zen Man? :< |
| Posted by: 6 2006-05-03 17:14 |
| #11 Seems to me I've read dozens of stories about laser weapons, some being implemented, others in various stages of R&D. This is just one of many. I can see the Democrats being against it - the Democrats have been against every weapon development program since the F-100. As for the Republicans fighting this, those that voted against it need to be fired at the next election and replaced with someone who has a brain instead of a reflex circuit. The Russians spent tens of billions of rubles on laser weaponry, knowing it was a winner for the guy that got there first. Failing to pursue laser weapons for any reason is insanity. There's nothing good about being "second" in any type of weapons program, especially with someone as paranoid as the Russians and Chinese. |
| Posted by: Old Patriot 2006-05-03 16:06 |
| #10 Adaptive or agile optics, anti-satellite lasers and guide stars are all ideas and technologies that are decades old. Efforts to reduce the form factor of such engines might be somewhat new, but 90% of this article is old news. I was working on primary laser optics for a multi-megawatt anti-sat FEL (Free Electron Laser) in the mid-1980s. |
| Posted by: Zenster 2006-05-03 15:54 |
| #9 Also, if you've such lasers, you can adapt them to lunching payloads to LEO. |
| Posted by: gromgoru 2006-05-03 14:26 |
| #8 Is it in a hollowed-out volcano, like I asked? |
| Posted by: mojo 2006-05-03 14:23 |
| #7 C4I, Ptah? I've thought of Command and Control, but what are the others, please? |
| Posted by: trailing wife 2006-05-03 14:15 |
| #6 What reason is there at present for such weapon technology? Simple. Size the high ground before someone else does. If we can knock out commmunication and military satellites and our potential enemies cannot, it makes the prospect of a war more remote. Most sane (Iran excluded) countries don't take on the biggest kid in the schoolyard when they KNOW he can kick your ass. Both China and the EU are developing their own GPS systems so they won't have to use the US one and will sell it to other countries. Countries that may very well end up trying to fight the US. Can you imagine what could happen if Chavez had GPS enabled cruise missles that used Chinese tech? The aircraft carrier task force in the area could be on the receiving end of several hundred missiles, all very, very accurate. Knock the satellites out, and you remove that threat and help blind your enemy. |
| Posted by: DarthVader 2006-05-03 12:27 |
| #5 BTW I remember reading about a ground-based laser idea, in the 70s, that was good for one great shot. The idea was: long tunnel at one end of the tunnel a mirror pointed back into the tunnel at the other end a 45 degree mirror pointed up to a steerable mirror with adaptive optics that would send the beam up to a cluster of sats that could bounce the beam between each other until sending it down to some target. about 3/4s of the way down the tunnel an A-bomb. The option of mirroring the tunnel walls or covering them with fiber or wire rods (wire for x-ray lasing). Another option would fill the tunnel with a liquid or gas that would provide a prefered lasing frequency. This would make the tunnel a one shot nuke powered laser. (a massively powerful laser beam) |
| Posted by: 3dc 2006-05-03 12:13 |
| #4 First target? Certain idiots in the House! |
| Posted by: 3dc 2006-05-03 12:04 |
| #3 Space is the ultimate watchtower. Attacking the enemy C4I when the enemy is a control freak that is scared of independent thought in the trenches or the officer corps is the quickest way to dismantle those types of armies. And ya gotta start someplace to get to laser weapons that can take out artillery shells, missiles, Qassams (hint, hint), and ICBMS. The Blunderbuss was a nightmare to use, but it was a start, and eventually led to the weapons we have today. Same here. |
| Posted by: Ptah 2006-05-03 11:18 |
| #2 What reason is there at present for such weapon technology? |
| Posted by: Bernardz 2006-05-03 10:50 |
| #1 Definately feasible. Rumor has it the Soviets started something like this. It would be nice to use against the "new" GPS systems the Chinese and EU are building. |
| Posted by: DarthVader 2006-05-03 07:51 |