China tests ASAT

Discussion in 'Strategic Defense' started by tphuang, Jan 18, 2007.

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  1. Hendrik_2000
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    Hendrik_2000 Brigadier

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  2. Sea Dog
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    Sea Dog Junior Member
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    I'd actually like to know more about this test. Doesn't seem to be much of a big deal. China apparently moved this weather satellite so it would be in-plane making it an easy target. They orbit raised it's altitude and moved it's ground track. Looks like they validated a vehicle with an intrinsic ability to hit targets with predictable tracks out of the atmosphere (which is not technically hard), but haven't shown a real ability to be very capable against real satellite targets.

     
  3. Macbeth
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    Macbeth New Member

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    Previous anti-satellite weapons tests, conducted during the Cold War, involved either co-orbiting killer satellites (the Soviet approach) or an air-launched anti-satellite missile (the U.S. approach, also considered by the Soviets but never attempted). Some tests involved shooting ground-based anti-missile missiles toward satellites, but those missiles never hit their mark.

    That's because it's hard to nail an orbiter, traveling hundreds of miles up at thousands of miles per hour, from the ground. The fact that the Chinese were able to do it could have troubling repercussions beyond space, as one commenter to the FPSPACE list notes:

    Assuming the [Chinese target satellite] was on the order of 3 meters in size, and assuming the kill was made in direct ascent mode as opposed to co-orbiting mode, this test demonstrates the capability to achieve a velocity error on the order of 3 meters / ~1000 seconds, i.e., way less than 1 cm per second. This has obvious implications for their CEPs [Circular Error Probables, the accuracy] of Chinese ballistic missiles.

    Now, Beijing seems to have cheated just a bit in this test, Oberg observes.

    The last orbital data released by NORAD seem to show one end of the [Chinese target] satellite's orbit being raised by about 20 miles (32 kilometers). Such tweaking is characteristic of a satellite lining up its orbital path for a rendezvous with a ground-launched visitor. The international space station does this in preparation for Russian spacecraft visits.

    In fact, the reason the U.S. Air Force chose the air-launched anti-satellite system is that it does not have to have its target line up with a ground-based missile pad. Naturally, a real target in the real world would never make such a helpful maneuver.

    Without the target’s maneuver to make itself easier to kill, a ground-based shot would likely have to be made from the side — or “out of plane,” in space navigation parlance. With such a geometry, the final approach for physical contact occurs under much higher rates of angular change, making terminal guidance much more difficult. It can be done, but with less reliability.

    But even with some fudging, this remains a very serious technical accomplishment. Oberg's piece has lots more -- including some possible (repeat, possible) countermeasures to a satellite strike. Be sure to read the whole thing.

    Of course, for a long time, directly attacking the orbiter with another piece of metal seemed like the least likely, least effective way to knock a satellite out. Since 2004, the U.S. Air Force has had in its arsenal a series of radio frequency jammers, to interfere with satellite operations. Three or four times a year, small groups of junior officers gather at an Air Force Research Laboratory facility in New Mexico to figure out how to take American satellites off-line using nothing more than sweet talk and off-the-shelf gear.

    Then there are the lasers. Not only did China recently light up an American orbiter with a ground-based laser. But, as Dan Dupont reminds us, the U.S. military spent much of the 90's testing out a satellite-shooting beam weapon of its own: the Mid-Infrared Advanced Chemical Laser, or "MIRACL."

    "In October 1997, the Air Force commissioned a test of an ASAT [anti-satellite] system based on the MIRACL laser," the Union of Concerned Scientists notes. "This system was directed toward a satellite orbiting 420 km above the Earth. The MIRACL laser apparently had technical difficulties, but the results of the test were startling."

    A lower-power (30-watt) laser intended for alignment of the system and tracking of the satellite was the primary laser source used during the test, and it appeared that this lower-power laser was sufficiently powerful itself to blind the satellite temporarily, although it could not destroy the sensor. That a commercially available laser and a 1.5 m mirror could be an effective ASAT highlighted a US vulnerability that had not been fully appreciated. Although the Pentagon described the test as defensive (i.e., to learn about the vulnerability of US satellites to laser attack), many—in particular the Russians—expressed concern about the offensive capabilities of this system and whether it constituted a breach of the ABM [anti-ballistic missile] Treaty, and formally requested negotiations on an ASAT weapon ban.

    http://www.defensetech.org/archives/003184.html
     
  4. XcOdeZ9x
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    XcOdeZ9x Just Hatched
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    very interesting news and china pull out a very amazing technical feat. this asat is with a kinetic vehicle hiting a satellite 500+ miles moving at thousands of miles per hour. not very very easy at all. this is one is also higher than the last u.s. test which was 300 miles.

    which makes me ponder, what else does china have?? china could probably take out u.s. satellite by lasers as they said china "illuminated" a u.s satellite.
    can china can possibly take a out a United States aircraft carrier using long range ballistic missile? what about high powered lasers? because if i was china, i would want to take out high value u.s military assets shockingly and create a frightening psychological effect as chinese generals plan to do. this is much more effective and more scary than fighting and taking out a u.s. carrier using planes and submarines even though subs can probably do the job the less sexy way. i don't know if there is any defense system on ships that could take out a modern ballistic missile?

    if china blows up an aircraft carrier during a war using long range ballistic missiles or high powered lasers, u.s. is going to quit and don't want to really fight a conventional war anymore. that would probably the most annoying thing ever to occur for the u.s.a.
     
  5. DarkEminence
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    DarkEminence New Member

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    A plausible explanation: the satellite was moved so that 1) It would resemble a high altitude space satellite 2) so that the dangerous fragment crowd wouldn't damage any other satellites...except those annoying high altitude spy satellites.
     
  6. LiLaZnMaGiCsCt
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    LiLaZnMaGiCsCt New Member

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    Exactly. It's not a big deal. If China has ASAT Missiles, and it's a threat to US. What kind of threat of the US having ground-based ASAT laser weapons to China? A much more bigger one.
     
  7. Sea Dog
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    Actually, technically very easy if it's done in-plane. And that's what it appears to be. I'm willing to bet the relative velocity on impact was probably relatively low.

    LEO satellite constellations are not all placed at the same precise altitude. And predicting where these fragments would park in orbit is not something easily determined.

    It looks like they purposely moved the vehicle and orbit raised it to make it an in-plane shot. Coupled with the fact that it has a predictable, stable, in-plane trajectory, it's not that big of a deal at all. Quite easy from a technical POV. Anybody can do that. In fact, it's done all the time in regards to rendevous and docking maneuvers. If they fired on a cross track LEO sat with an orbital velocity of 5,000 - 7,000 m/s (of course dependant on actual altitude) I would be impressed.

    No. Of course it's a threat to U.S. and allied space satellites. I'm just saying that they haven't demonstrated that much with this test. Nor does this prove that U.S. and allied satellites are definitely at risk. And I'm not too surprised by the orbit raising maneuver. I'm more concerned they are working toward this capability at all. But it's something the U.S. will deal with if they ever do get a robust capability to destroy space assets at will in any plane, at any altitude. This test doesn't prove it.
     
    #77 Sea Dog, Jan 20, 2007
    Last edited: Jan 20, 2007
  8. XcOdeZ9x
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    no, it is not very easy at all. you are trying to hit a target that is moving thousands of miles per hour at 500+ miles. not easy at all.....i thought the speed of the kinetic vehicle impact was very high since it smashed the satellite into a lot of pieces and created lots of space debris?
     
  9. Schumacher
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    Schumacher Senior Member

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    One has to understand the dilemma & mindset of a certain small section of US military observers. On one hand, trying to exaggerate threats from PLA but on the other, desperate to downplay any kind of tech achievements from them. :)
    But having said that, it's not surprising if indeed PLA, just as USAF & others, did simulate some 'easier' test environments, that wouldn't be present in real life situations, in order to achieve their military or political goals from the test.
     
  10. Sea Dog
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    In terms of speed, I'm talking "Relative velocity". Yes, very fast. Enough to break a satellite up. But in an in-plane track, not as fast. Things move very fast in LEO. So I'm talking relatively speaking. And yes, it's effective enough if it does the job of destroying the satellite. :) But this was setup in-plane. Most satellite orbits aren't going to be so flexible as to allow such an easy target.

    And no. It is technically very easy. Both Russia and the USA have closed distances between orbiting vehicles for the last 40 years. From both in and out of planes. From launch to orbit as well. For many purposes including ASAT. Like I said, I would be impressed if it was from a cross track vector. From what it looks like though, they set it up to make it easy. Orbit raising slows the vehicle. Changing a satellites inclination angle to align in-plane makes targeting calculations dimensionally simple. This is the stuff that they learned from Loral (U.S. engineers) in the 90's. As far as the "Kinetic Kill" vehicle, I'd love to know how it exactly guided to the satellite after deployment from the booster. I think I read that it used some sort of laser guidance?
     
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