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18 January 2007 |
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http://www.defensetech.org/archives/003181.html |
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More items on this topic here "China performed a successful anti-satellite weapons test" last week, according to Aviation Week. In the trial, a ballistic missile, armed with a non-explosive warhead, "destroy[ed] an aging Chinese weather satellite target" over 500 miles above the Earth, U.S. intelligence agencies believe.
Harvard University's Jeffrey Lewis, a self-admitted skeptic about China's space ambitions, has been hearing from many sources in recent months that "China’s ASAT work seem[s] to have been ramping up." He writes over at his blog, Arms Control Wonk:
(Big ups: EM) UPDATE 11:42 AM: Why would Beijing pull a stunt like this? The China Matters blog has a theory. Meanwhile, one keen space-watcher notes that, if this anti-sat weapon was really "kinetic" -- i.e., hit-to-kill, non-explosive -- instead of a plain ol' exploding weapon, that's extremely bad news. That means the booster rocket has to be very accurate "in order to deliver the kill vehicle to the desired initial trajectory.... Then the kill vehicle needs to tweak its trajectory into a precise collision course using on-board propulsion and either on-board target tracking or... command guidance from the ground." That's no mean task. ALSO:
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18 January 2007 |
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http://www.defensetech.org/archives/003183.html |
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More items on this topic here China has shown it can destroy a satellite in orbit. What could the U.S. do to stop Beijing, if it decided to attack an American orbiter next? Short answer: nothing.
The American military today counts on its satellites to relay orders, guide troops across battlefields, and spy on enemy hideouts. The U.S. Air Force's primer for war in space -- "Doctrine Document 2-2.1: Counterspace Operations" -- lists a number of measures that can be taken to protect American assets in orbit, including "deploying satellites into various orbital altitudes and planes" and "employing frequency-hopping techniques to complicate jamming." But those tactics are used to preserve the U.S. satellite constellation as a whole. None of them could save a single American orbiter against a direct attack. "Physical hardening of structures mitigates the impact of kinetic effects, but is generally more applicable to ground-based facilities than to space-based systems due to launch-weight considerations," the Air Force document notes. "Maneuver[ing] is limited by on-board fuel constraints, orbital mechanics, and advanced warning of an impending attack. Furthermore, repositioning satellites generally degrades or interrupts their mission." With today's conventional defenses proving so impotent, expect a new push within the U.S. military for more exotic countermeasures. The Airborne Laser is a modified 747 that's being designed to blast missiles out of the sky, as soon as they leave they launch pad; the jet's first flight test in expected in 2009, after years and years of delays. The Kinetic Energy Interceptor is a long-range, non-explosive missile, meant for the same task. But the weapon "exists mostly on paper, and couldn't be operational before 2014," Defense Tech's David Axe noted recently. The U.S. could also try to destroy an anti-satellite missile, before it took off. Over the last several years, momentum has been building in the Pentagon for the ability to conduct "Prompt Global Strikes," hitting anywhere on Earth, in an hour or less. But near-term PGS plans -- using modified Trident ballistic missiles -- have been put on hold, for fears that such an attack could start World War III, in the process. Destroying a satellite is as clear an act of war as there can be, however. Perhaps those Trident attacks will now be seen as worth the risk. In the meantime, GlobalSecurity.org director John Pike figures the Chinese will continue to test their satellite-killing weapons. It takes a dozen or more trials before a strategic weapon like this is deemed reliable enough to be considered operational. "So expect one or two more tests like this every year, for a long time," he says. The Chinese test, now confirmed by the National Security Council, would be the first successful anti-satellite weapons trial since 1985, when the United States used an F-15 and a kill vehicle to destroy the Solwind research satellite. And that trial was dangerous -- not just for its target, but for nearly everything orbiting in space, Hitchens notes. Even small pieces of space debris can be lethal to spacecraft. The '85 test "resulted in more than 250 pieces of debris, the last of which deorbited in 2002." The Chinese trial could "lead to nearly 800 debris fragments of size 10 cm or larger, nearly 40,000 debris fragments with size between 1 and 10 cm, and roughly 2 million fragments of size 1 mm or larger," the Union of Concerned Scientists' David Wright notes on the Arms Control Wonk blog. "Roughly half of the debris fragments with size 1 cm or larger would stay in orbit for more than a decade." "This raises an interesting public policy question because we are so much more dependent on commercial and military satellites that the ASAT [anti-satellite] options available to us are much more complicated than those available to the Chinese," adds Jeffrey Lewis. "This is a race that favors them, unfortunately." ALSO:
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18 January 2007 |
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http://www.nytimes.com/reuters/washington/politics-china-usa... |
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More items on this topic here WASHINGTON (Reuters) - The United States, Australia and Canada have voiced concerns to China over a test in space of a satellite-killing weapon last week, the White House said on Thursday. ``The U.S. believes China's development and testing of such weapons is inconsistent with the spirit of cooperation that both countries aspire to in the civil space area,''
Using a ground-based medium-range ballistic missile, the test knocked out an aging Chinese weather satellite about 537 miles above the earth on January 11 through ``kinetic impact,'' or by slamming into it, Johndroe said. Canada and Australia had joined in voicing concern, he said. Britain, South Korea and Japan were expected to follow suit, an administration official added.
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