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US Satellites Dodging Chinese Missile Debris
GSGKT writes "Today's Washington Times runs a story about the increasing problem with space junk orbiting the earth. Debris from the anti-satellite missile test by the Chinese military last year threatens the integrity of more than 800 operating satellites, half of them belonging to the US. Two orbiting U.S. spacecraft were forced to change course to avoid being damaged soon after the incident. Air Force Brig. Gen. Ted Kresge, director of air, space and information operations at the Air Force Space Command in Colorado, estimates that
"essentially (Chinese anti-satellite tests) increase the amount of space debris orbiting the Earth by about 20 percent", and the debris might threaten spacecraft for up to 100 years."
Half of the threatened satellites are American owned, not half of the debris.
My only political goal is to see to it that no political party achieves its goals.
RTFA.
According to the Joint Space Operations Center at Vandenberg Air Force Base in California, the commercial communication satellite Orbcomm FM 36 maneuvered to avoid passing within about 123 feet of the debris field on April 6. A NASA Earth observation satellite Terra was moved June 22 to avoid coming within about 90 feet of the debris.
This is probably the best "Denial" type weapon developed. In the case of the chinese, if there was ever a major threat to thier sovereignty they could make the whole orbit plane into a huge denial zone, crippling the more advanced nation that relies on that area, while giving themselves the advatage of using an army that hasn't learned to rely on satellites. the whole mentality of "if we can't have it, neither can you" works very well in warfare. Scorched earth... just taken to the next level.
made the space over China less habitable to spy satellites
You're not real familiar with how orbits work, are you?
Since that crap is in low orbit, I'm pretty sure it circles the entire planet every couple of hours.
Unless, of course, the Chinese have developed some sort of non-newtonian thruster system that lets their space trash hover in one place.
Clear, Dark Skies
Once every 90-odd minutes, actually.
Marvin knew: "Think of a number, any number..."
"The US military is completely dependant on their technology and the rest of the world knows it. Do their cruise missiles even work without GPS?"
The US has no weapon systems that are GPS guided and never has, precisely because it is vulnerable. The Chinese may have just now gotten around to developing anti-satellite technology, but the Soviet Union had it ages ago.
The core guidance package of US weapon systems is extremely high precision inertial navigation (all systems described as "GPS-guided" are actually inertial -- the media is a bit stupid about these things, as GPS is an optional untrusted overlay on inertial navigation systems). Some intelligent terrain following weapons also use optical geo-referencing. As a matter of policy going back to the Soviet Union days, the US military machine views satellite systems as "nice to have" but its infrastructure is pervasively designed to operate under the presumption that there are no satellites in orbit. The vulnerability of the US military to massive system outages is greatly overstated; the Soviet Union was a much bigger threat on this scale than the Chinese are, and the US military has always been pretty religious about designing systems whose functionality was robust and in the face of rapidly degrading military infrastructure and relatively decentralized. It is easy to forget it, but the Chinese have nothing on the old Soviet Union in terms of technology and force numbers, and that was the doctrinal enemy of much of the modern US military.
The satellite and resulting debris field in question are in low Earth orbit not geostationary orbit and therefore do not remain over the same location on Earth.
Some of what I say is fact, some is conjecture, the rest I'm just blowing out my ass...you guess.
"*cough*JDAM*cough*Tomahawk*cough*F-16*cough*
Sorry got something stupid stuck in my throat. Anyways as I was saying the US has plenty of weapons sytems that use GPS systems and would either become completely ineffective or seriously crippled without it."
As was pointed out elsewhere, neither JDAMs nor Tomahawks (nor F16s for that matter) use GPS guidance -- only technically ignorant tools claim that any US weapon systems use GPS guidance. Even rudimentary research shows that systems like JDAMs and Tomahawk get their navigation data from ultra-precise laser ring interferometers (an extremely precise solid-state optical accelerometer with a purpose similar to mechanical gyroscopes), with the ability to optionally accept GPS fine-tuning corrections. The precision of the inertial systems is classified, but it is generally known that it is apparently not much worse than the GPS corrected version for weapon targeting purposes (they may have already converged for all we know -- INS has been continuously improved, and it wasn't bad to start with). Note that this is also why jamming or toying with the GPS signal does not send bombs and such flying way off course; the inertial system only accepts corrections within the computed error bars of its own positioning data. If the GPS signal is outside those bars, the navigation system assumes the GPS has been compromised.
I just gotta love the armchair weapon designers who think that of the thousands of bright engineers that built all these weapons, it never occurred to anyone that someone might jam or disable the weak RF signal that is GPS. GPS is a convenience, not a necessity, and it would only have small impact on the efficacy of American weaponry -- by design. The reason the US military embeds inertial navigation in everything is precisely because it is essentially impervious to countermeasures short of altering the physics of the universe. For all we know, nominal GPS weapon targeting is largely for show and indirection, since it costs next to nothing to strap a GPS receiver on an inertial navigation system (and it would seem to have worked in that case, considering how much breathless idiocy is fixated on GPS weapon targeting).
As a point of trivia, the laser inertial navigation systems used by the US military were invented in the 1960s for some (failed) ballistic missile interceptor research. Even though the ABM research was a dead end, the laser ring gyro technology developed for the project paid dividends for the US military way out of proportion to the money expended on the ABM research.