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U.S. Plans I: Pentagon Pursues Mini-Interceptors to Answer Decoy Challenge By David Ruppe The envisioned technology is a package of 20-40 “miniature kill vehicles,” each the size of a softball and weighing two kilograms. If successfully developed, these warhead interceptors might be launched on a single missile to attack a cluster of multiple targets in space. That capability, experts say, could significantly reduce the challenge of requiring one kill vehicle to distinguish a warhead from a cloud of decoys and other objects surrounding it. The miniature interceptors could possibly attack everything. The miniature kill vehicle (MKV) represents for the military a potential paradigm shift in strategy from “a sniper to a shotgun,” according to one military presentation on the technology. It is an idea that even some missile defense critics are applauding. “I guess it’s a terrific idea if you could make it work,” said Steve Fetter, a physicist and professor in the School of Public Affairs at the University of Maryland. “But in order to make it work against countermeasures these would have to be very small, so you could put say a hundred on a ground-based interceptor.” “I’m actually quite intrigued by this idea. It’s very close to an idea I proposed a little while back,” said Massachusetts Institute of Technology professor Theodore Postol. High Risk Critics say, however, that the system still might be fooled by certain countermeasures. “It certainly has a significant advantage in terms of creating many more shots at a small cluster of objects, but it appears on the surface that there would be relatively straightforward countermeasures against it anyway,” said Postol. A senior U.S. official who described the program in detail said the program is “high risk.” “Functionally,” all kill vehicles are the same, having the same kind of components, said the official. “What we’re trying to do is push the state of the art on the miniaturization side of things.” The Navy’s theater missile defense “LEAP” interceptors, which weigh 15 kilograms, employ some miniaturization technology, the official said (see GSN, Jan. 28). “We feel the technology with electronics and with seekers allow us to go to the next step with miniaturization.” Fetter said he agrees. “There are all sorts of things you can do if you are clever,” Fetter said. “It seems to me the only practical way to salvage the midcourse concept.” Good Idea, If It Works For years, the U.S. military has been developing a 60-kilogram Exoatmospheric Kill Vehicle (EKV), only one of which might be launched aboard an intercepting missile. This midcourse ground-based system, intended to knock threatening warheads out while they are in space, is one of the most expensive and high-profile of at least a half-dozen major U.S. programs — in various stages of conception and development — designed to destroy ICBM-launched warheads in various stages of flight. Critics have charged that that single kill vehicle could easily be fooled and the missile shot wasted if decoys surround the target warhead. For example, a single, shiny Mylar balloon sheath could hide a warhead among other similar balloons. The system “has little chance of being effective, because states capable of deploying intercontinental-range missiles armed with weapons of mass destruction would also be able to deploy countermeasures that would defeat the system,” wrote Fetter in a co-authored article published last summer in the journal International Security. The article suggests miniaturized kill vehicles as a solution, but adds that the program would go “far beyond the boundaries of the currently planned system.” Cost Tradeoffs The principal challenge is containing the cost per kill vehicle, the senior U.S. official said. While size and weight are important, “what we really need to go after is the cost,” the official said, adding that reducing cost could entail a tradeoff in terms of how accurately the miniature kill vehicles can be guided toward a target. “We’ve got to make sure we can build these things so they’re not $1 million a copy, but tens of [thousands of dollars] a copy. That will allow us to have a lot of them on a vehicle,” the official said. “We know we’ve got the technology in hand, I think, to get the miniaturization. The real issue is can we bring the cost down.” Reducing cost, the official said, involves a tradeoff in terms of how accurately the miniature kill vehicles can guide themselves toward a target. The kill vehicles would be housed on a “carrier vehicle,” which would be launched toward a “threat cloud” of objects. If each kill vehicle were to home in on a target by itself, it would probably need to carry an infrared device and accompanying focal plane array and cooling system to track the object, which , the official said, could cost a great deal. Also, there could be a challenge in miniaturizing the infrared sensors and accompanying equipment like a cooling system, said Wright of Union of Concerned Scientists. The larger EKV uses infrared to home in as it nears a target. A Lighter-Weight Solution The “most likely” idea under consideration, the official said, is to equip the vehicles with much cheaper and much lighter “visible seekers,” which would detect sunlight reflected off the target. The kill vehicle might employ a telescope that focuses the optical energy onto a sensor such as a charge-coupled device used in a digital camera, according to the official. “The advantage of charge-coupled devices is because they operate in the visible, they don’t need to be cooled to a very low temperature for them to function,” Postol said. The charge-coupled devices are commercially available and inexpensive, he said. “You get a vast decrease in complexity in the kill vehicle simply by using visible energy.” A laser designator could be deployed on the carrier vehicle to guide the kill vehicles to their respective targets, particularly in the Earth’s shadow when no sunlight is present. The type of laser that might be needed to provide sufficient targeting accuracy also could impact cost, the official said. Another potential tradeoff, according to the official, involves the propulsion system of the kill vehicles. “You want to go after threat clouds where the objects are reasonably close spaced as opposed to all over the place,” the official said. “If the threat cloud is very, very big or the objects are all over the place, this thing will break down because you’ll have to put more and more propulsion fuel in these little things, and then that adds the weight, and you’re not going to maintain your two kilograms.” Alternatively, fewer, bigger and heavier kill vehicles could be deployed, the official added. “So those are tradeoffs we still have to do.” More Challenges Another challenge is deciding what type of sensor to put on the carrier vehicle to ensure it can maneuver toward the threat cloud. The launch mechanism is another concern. “You just don’t drop these things off. You’ve got to aim them. So does that mean the carrier vehicle has to maneuver around, and how much of a timeline do you have to start [launching] these in particular directions?” the official said. Authorities must also decide a battle management philosophy, according to the official. “Are we going to assign [the kill vehicles] one-on-one, or are we going to have several of these attack one [target]?” the official said. “How do these things decide themselves what to attack?” There is also a “lethality issue,” given the relatively small mass compared to a potential warhead, and the EKV for that matter. If the reentry vehicle (RV) housing the targeted warhead is not struck in the right place, it and the warhead may not be sufficiently destroyed. “This is an accuracy problem,” the official said. “We might have to have several of these attack the RV or they would have to be very accurate and hit a specific point on the RV, a tradeoff of cost once again.” “These things clearly will kill balloons. We have to make sure they’ll kill an RV, and that’s a tradeoff of accuracy,” the official said. Fetter said he believes even a one-kilogram kill vehicle would be sufficient, as it would be traveling at an extremely high closing speed of 15 kilometers per second. “That’s plenty,” he said. Questions About Effectiveness Experts said miniature kill vehicles would face many of the same troubles overcoming countermeasures as would the larger EKV. “You are reflecting light off objects, and there’s no reason to believe that you would be able to do tremendously better telling a decoy from a warhead with a laser,” said Postol, though he said that challenge is offset by having numerous kill vehicles. Postol said it is also fairly easy to make clouds of reflecting materials, such as frozen water droplets, that could surround a warhead and decoys and confuse sensors. Since the system would employ an infrared sensor to track objects, it might still be foiled if a warhead is sufficiently cooled and hidden in a balloon, said David Wright, a senior staff scientist at the Union of Concerned Scientists and author of a widely reported study in April 2000 arguing simple countermeasures could foil the EKV system. “If the infrared sensors can’t detect it until it is too late, it doesn’t matter how many there are,” he said. Another potentially effective countermeasure, he said, would be to embed a warhead in a very large balloon so that an interceptor might have a low chance of hitting the warhead if it hits the balloon. “You make the balloons so much bigger than the warhead, and the probability that you could kill the warhead is still pretty low,” he said. “There are still easy ways to get around this.” Information released by the Army suggests that at a minimum, the system could eliminate large numbers of decoys so another — possibly larger — infrared interceptor could finish the job. An alternative to precise targeting, according to the senior military official, might be to direct several kill vehicles into a small area, so that the warhead would have a good chance of being struck. Funding This Year The military has in the past invested some money in pursuing the MKV concept, but this year the Missile Defense Agency ratcheted things up. The Army expects to spend $11.5 million in fiscal 2002, has requested $15 million for 2003, and projects to spend $25 million for 2004. The U.S. Army Space and Missile Defense Technical Center in Huntsville, Alabama, awarded three such contracts to teams of Lockheed Martin and Coleman Research, Schafer and Boeing, and SAIC and Raytheon in mid-February for concept definition studies, basically to work out some of the tradeoffs. After a year, two teams will be chosen to do detailed studies, including designs of the kill vehicles and the carrier vehicle. Two other contracts were awarded to Shafer and SAIC to perform experiments to demonstrate the capabilities of various miniaturized elements. “To show we’re in the ballpark of feasibility, with respect to size and weight,” the official said. After a year, one will be chosen for further demos. The goal is to begin flight-testing by 2005. Allaying Russian and Chinese Concerns Fetter has argued against developing a midcourse missile launched national missile defense system, principally because it might present a threat to the offensive ballistic missile systems of Russia and China, possibly inciting those countries to deploy larger force numbers than currently planned and possibly put them on a higher, more perilous state of alert. If fewer interceptor missiles need to be built as a result of the new technology, deploying the miniature kill vehicles might work to alleviate Russian and Chinese concerns about their own deterrent force, Fetter said. That “should generate less concern for Russia and China,” he said.
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