USA 193 Shootdown Set For Feb 21, 03:30 UTC

An anonymous reader writes "Amateur satellite watcher Ted Molczan notes that a "Notice to Airmen" (NOTAM) has been issued announcing restricted airspace for February 21, between 02:30 and 05:00 UTC, in a region near Hawaii. Stricken satellite USA 193, which the US has announced plans to shoot down, will pass over this area at about 03:30. Interestingly, this is during the totality of Wednesday's lunar eclipse, which may or may not make debris easier to observe."

Comments

I wonder

[cslax]

if they chose the eclipse date on purpose. We'll wait and see what they say AFTER it all happens.

Oddly enough...

[Anonymous Coward]

... they're going to use a pop bottle to do the deed.

Good coverage

[BWJones]

Bruce is a fellow satellite spotter also with some degree of background and in the subject matter and has good coverage here.

Re:Good coverage

[Cassius Corodes]

There is also some interesting analysis done by the Federation of American Scientists that suggests this is just an excuse to test out some anti-satellite missiles. An interesting read.

http://www.fas.org/blog/ssp/2008/02/us_plans_test_of_anti-satellit.php

Re:Good coverage

[twiddlingbits]

FAS always raises hell over weapons tests of any kind. What else is new.

The SM-2 to be used is actually being MODIFIED with new software to try to do the intercept. It's not certain it'll work. So I guess that makes it a test.

The eclipse likely makes it easier to spot the "target".

But at least we aren't leaving a shitload of crap to fuck up usuable orbit space like the ChiComms did in their ASAT test. This bird is coming down NOW so why not test on it. It's cheap, if it works maybe we have a new use for an existing system w/o spending millions, we clean up our own mess by shooting it down, the debris will come down (with some risk as it's smaller pieces) and not clutter the crap out of orbital space, and we trash anything secret the enemy might try to capture (assuming it survived re-entry..but why risk it?). Sounds like a bargin "test" to me.

Re:Good coverage

[icebrain]

I'd expect that shooting a satellite whose orbit is already decaying might hasten the process by a couple days (smaller pieces would generally have a lower ballistic coefficient and therefore decay faster), but not by a significant amount.

The real benefit (to the US) is that turning a big, expensive satellite with lots of classified equipment on board into a bunch of little satellites means that the expensive bits are rendered unusable and far less likely to get to the ground intact, where they can be analyzed. It also provides a good opportunity to test a new missile system, and shows the Chinese that the US can play at their game, too.

Re:Good coverage

[hax0r_this]

Well, there may be some truth to it. But like most decisions, there are a lot of things at work here:

1. Having a giant hydrazine tank land on someone's house would be a PR nightmare.

2. Having a spy satellite presumably filled with highly-classified stuff fall into the wrong hands is something They(tm) try to avoid.

3. Demonstrating to the rest of the world that we can blow their satellites into much less useful pieces is somewhat in line with the agenda of the Bush administration.

4. It can also be pointed to as a success of the missile defense program.

So I wouldn't write off the whole hydrazine tank issue entirely, but I doubt its the primary motivator.

Re:Good coverage

[everphilski]

Now, instead of one big vaguely predictable chunk of technology falling down, we're going to have hundreds if not thousands of smaller chunks that are going to be absolutely impossible to predict their trajectory.

As someone whose day job is re-entry of large objects from near-orbital velocities I feel pretty qualified to respond to this. "vaguely predictable" is pretty generous. For the upper stage of a launch vehicle re-entering under an hour after launch (read: we know precisely where it is coming from, have the trajectory modeled, etc), there are thousands of miles in the "footprint" of the debris. And while most of it will come down in one or several big chunks, there will be a lot of scatter debris over that footprint. Now, think of something that's been in orbit for a number of years. Sure, we can observe it for a few months and try and nail the orbital parameters, but any way you slice it, it's an uncontrolled re-entry. We don't know with high precision the injection orientation, velocity, orientation, etc. That baby could have an uncertainty of 10,000 miles or more on it's footprint.

Also another note: big, dense, heavy things tend to break up very little on re-entry. They soak a lot of heat and come down hard and heavy. Big, light things like expended stages tear apart into little pieces and essentially dissipate in the atmosphere, leaving very little debris. And what debris remains, slows down very quickly, reducing scatter versus heavy pieces that just keep on flying. So there is a distinct advantage to breaking this thing into pieces. It will tear itself to shreds, versus coming down like a rock.

there's even the risk that the explosion might send pieces of debris upwards in the atmosphere, and it may even reach an altitude that will not allow it to fall back down for a very long time.

Don't believe everything you read on slashdot. What goes up must come down. The only way it will stay in orbit is if you give it the appropriate energy tangential to the surface of the earth to sustain an orbit, or more. That's it. I could shoot a bullet up into the sky right now at M=10,000, and it's either escaping the gravitational grasp of the earth or coming back to hit it. The chances of random pieces entering a stable orbit for the long term is slim. The chance of a few random pieces extending their stay? Granted, maybe for a few months to a year.

Conspriacy goldmine

[bluelip]

A super secret sat is not responding for unknown reasons. This requires a shootdown which just happens to occur during a lunar eclipse.

Wow, who gets the movie rights for this one?

Moon hiding behind megameters of solid rock

[isomeme]

Since that time interval occurs during daylight hours near Hawaii, with the eclipsed moon (necessarily) below the horizon, I doubt the eclipse will have much effect on visibility. :)

...which may or may not

[Daimanta]

This post may or may not be a way to tell you that may or may not is a totally ambigious statement. Some people may or may not notice this. I may or may not be modded Offtopic but I can also be modded +1 Funny or +1 Insightfull. However, this may or may not be the case.

good information there!

[Bob54321]

which may or may not make debris easier to observe

Way to limit the two choices down to two choices....

Isn't it obvious?

[QuantumG]

That this is just a response to China's ASAT test of January last year?

China: you see, we can blow up your satellites!!
USA: aha! We can blow up your satellites too!!

General public: Why are they blowing up satellites?

During the eclipse?

[PPH]

No doubt goats will be slaughtered, wiccans consulted, and pentagrams drawn all in the hope that our missile intercept technology will actually work in a non-staged event.

Re:Nothing to see here, move along

[Rei]

I find it quaint, the notion that the real reason they have to shoot the satellite down is because it has a tank of hydrazine onboard. Meanwhile, the Russians have let *freaking nuclear reactors* reenter our atmosphere. It's pretty transparent that they're A) trying to upstage the Chinese, and B) prevent any tech from making it into the hands of hostile parties. Even more transparent than the whole thing with A.Q. Kahn:

1) Pakistan funds its bloody nuclear program via nuclear equipment sales.
2) The international community eventually can no longer look the other way.
3) Khan steps forward. "Whoops, it was me! My bad. Every sale we made to every single country, I arranged, negotiated, and shipped everything, all with government aircraft, all of my own. No Musharraf involvement, nosiree!"
4) Bush and Musharraf: "Bad Khan! Well, that case is solved."
5) "House arrest", of the kind that lets you travel across the country. No charges pressed. Everyone wins.

Re:Nothing to see here, move along

[Anonymous Coward]

I find it quaint, the notion that the real reason they have to shoot the satellite down is because it has a tank of hydrazine onboard. Meanwhile, the Russians have let *freaking nuclear reactors* reenter our atmosphere. No offense, but comparing safety concerns of the US with the Russians is sort of bizarre. They are the country that used to just drop old reactor cores in the oceans after all. I honestly don't think they cared that they tossed radioactive waste across Canada any more than they cared what would happen when they build enormous nuclear reactors without containment domes. And if you think these are minor issues of environment protection then look up their involvement in the Aral Sea disaster. Russia is the antithesis of environmental protection.

Outsource it

[Is0m0rph]

I'm surprised we didn't outsource this to China.

Three reasons

[jmichaelg]

I think there are three reasons they're spending $60 M to destroy the satellite. They are

1. They don't want a repeat of Skylab where parts landed in Australia and made us look bad.
2. If it comes down in Russia (Russia spans 11 time zones so that's not too unlikely) they don't want the Russians to be able to figure out much from the debris.
3. They want a chance to test their anti-satellite weaponry on a real target that isn't saying "Over here! I'm over here! Here I am! Yoo Hoo!"

There's actually a 4th reason - blowing stuff up is fun but they would never cop to it.

Re:Nothing to see here, move along

[Rei]

At least they never dared launch anything as crazy as Starfish Prime.

We are not the immaculate custodians of space that you seem to be picturing. Why, do you think, did we not shoot down the Delta II second stage that reentered in 1997 with a large amount of residual hydrazine and nitrogen tetroxide onboard? We have stages with signficant amounts of toxic residual fuel reenter all the time. Why, in the same year, when we had a Delta II explode *full* on liftoff, did the Air Force tell people in the *immediate area* that the smoke posed no danger? This was a *full launch vehicle*, not just a satellite's orbital maneuvering system. Do you have any idea how much beryllium we've had reenter? We sit by as large amounts of toxic materials enter all the time. As for the hydrazine itself, what do you think happens *on its own* to pressurized tanks of highly flammable fluids on reentry? I can't think of a *single* sizable object that's survived reentry still pressuretight.

The argument is completely bogus.