Sunday, March 27, 2011

Cousins Lead Libya Attack By Noah Shachtman, Wired.com, March 21, 2011 When the U.S. military wanted to take out Moammar Gadhafi’s air defense systems, it unleashed a barrage of 122 Tomahawk cruise missiles. But these munitions aren’t like most others in the American arsenal. Smart, maneuverable, able to see its surroundings and shift to new targets in mid-flight, the newest Tomahawks are closer to the unmanned planes flying over Afghanistan than to the weapons they fire. In some ways, the Tomahawk is the drone’s suicidal cousin: a robotic aircraft, packed with explosives, that has no intention of ever coming home. When officers get ready to shoot off a Tomahawk, “they are basically planning a flight for a little airplane,” one Navy official tells Danger Room. “It’s got stubby little wings — but is is an unmanned aerial vehicle.” The next-gen Tomahawks — known as “Block IVs” — start their flights out just like other missiles, launched from ships or subs. But after 12 seconds of flight, things change. The Tomahawk starts to fly horizontally, skimming above the ocean at a height of less than 50 feet to avoid enemy radar. GPS waypoints keep the missile on track, until it makes landfall. Then, a Tercom (Terrain Contour Matching) system kicks in. too. Using a radar altimeter, the Tomahawk Tercom checks its height. Then it matches that altitude against a database of satellite and overhead imagery, to make sure the missile is headed in the right direction and at the right height. Once the Tomahawk’s target is in sight, the missile can dart in for the attack. A Digital Scene-Mapping Area Correlator (“dee-smack” in military jargon) matches a stored picture of the target to the missile’s last sight, to make sure the two match. Or, the missile can wait a while. The Tomahawk’s controller can give it a new route, telling the Tomahawk to circle around in the air, lingering until an enemy pops up its head. Then comes the strike. Last May, the Tomahawk demonstrated a new move, as Sam LaGrone from Jane’s Defence Weekly reported at the time. The Los Angeles-class submarine USS Cheyenne fired off a Block IV at a target in the Mojave Desert. Meanwhile, a team from Naval Special Warfare Group 3 shot a second set of co-ordinates to the Tomahawk’s controllers in Japan, nearly 5,000 miles away. They reprogrammed the missile via satellite, and sent the Tomahawk crashing into a new target. (In an earlier test (.pdf), special operations forces were able to use the pictures taken from a handheld Raven drone to direct its bigger, more destructive relative to its end.) Cruise missiles have been around in one form or another since World War II, and Tomahawks have been schwacking American enemies since the days of Desert Storm. Some earlier models had nuclear warheads. Others (still in service) employ cluster-bombs, much to the chagrin of human rights groups, who hate how the minimunitions can linger on a battlefield long after a war is over. From the outside, the Block IVs look much like their predecessors: a little over 20 feet long, and about 3,300 pounds. Like the older models, they’re still expensive, too — at about $1.1 million a pop, the initial assault on Libya chewed through $134 million in missile costs alone. They can fly for about two hours or 1,000 miles, whichever comes first. But that could radically change, if an experimental Air Force program pans out. The X-51a aircraft is designed to test technologies for a next-gen cruise missile — one that would fly at six times the speed of sound. Which means tomorrow’s cruise missiles could be like suicidal, smart, and more than eight times faster than today’s Tomahawks. Generator Fails On U.S. Submarine By Andrea Shalal-Esa, Reuters, March 21, 2011 (Reuters) - The machine that produces fresh air aboard the USS New Hampshire submarine failed during a mission under the vast ice cap of the Arctic Ocean last week, prompting the submarine to use an alternate oxygen candle system instead. Hamilton Sundstrand, a unit of United Technologies Corp (UTX.N), is sending a representative to a temporary ice camp to investigate the problem with the oxygen generator, said Navy Commander John McGunnigle, captain of the nuclear-powered Virginia-class submarine. Daniel Coulom, a spokesman for Hamilton Sundstrand, confirmed late Monday that company staff would travel to the ship to help repair the oxygen generator, but said it was too early to speculate on what caused the problem. McGunnigle told Reuters he had spoken with the company shortly after the submarine surfaced on Sunday afternoon in a small area of open water surrounded by ice sheets. The ship is in the Arctic to participate in a month of military exercises with another submarine, the USS Connecticut. The emergency system that is now producing oxygen for the submarine's 130-plus crew burns chemical candles in a closed metal cylinder that vents to an air-circulating system. McGunnigle said the system was safe and crew members carefully monitored its use, but he acknowledged that it was the same kind of equipment that caused a fire and explosion on board the British submarine Tireless during a similar Arctic exercise in 2007, killing two sailors. Lieutenant Jason Revitzer, the ship's supply officer, said the ship had well over 600 oxygen candles on board, which would allow it to continue using the alternate system until it got back to its home port in Groton, Connecticut. "Good thing we packed that many," Revitzer said. McGunnigle said there were several other issues with the ship during the Arctic operations, including condensation caused by the temperature difference between the frigid water outside and warmer temperatures inside. For now, the crew has rigged sheets of plastic to catch any condensation drips and route them away from sensitive electronic equipment. The ship's air conditioning system, which keeps the sophisticated electronic equipment on board from overheating, also failed after its ascent to the surface, but the ship's crew was able to reset that system later. The USS New Hampshire, built by General Dynamics Corp (GD.N), is the fifth Virginia-class U.S. submarine, weighs 7,800 tons and measures 377 feet long, about the length of a football field. It entered service in October 2008. The ship cost about $2.4 billion to build, McGunnigle said, calling it one of the most complex machines ever built. Powered by small nuclear reactors, Virginia-class submarines can carry 38 different weapons, including Mark 48 Advanced Capability torpedoes, advanced mobile mines, unmanned underwater vehicles and Tomahawk land-attack missiles like those fired on Libya this past week. Virginia-class submarines were designed to have a minimal Arctic capability, including a strengthened sail that allows the ship to surface through thin ice without damage. On Saturday the ship had surfaced through nearly a foot of ice to evacuate a sailor stricken with appendicitis, but no damage was reported. Before any Arctic deployment, ships like the New Hampshire, are outfitted with special upward-facing sonar sensors that provide data on the ice sheets and keels above, as well as a special camera that provides video images of the ice overhead. The ships also have an acoustic top sounder system that measures ice draft and ice thickness. Submitted by Kirk Smith

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