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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."
Bruce is a fellow satellite spotter also with some degree of background and in the subject matter and has good coverage here.
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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. :)
When all you have is a hammer, everything looks like a skull.
I find your post a little hard to follow, however with regard to space debris, the satellite is sufficiently low that all the debris is expected to deorbit relatively quickly (days or weeks).
Grr! Arg!
I doubt the lunar eclipse has anything to do with it. The timing is almost certainly based on the need to get the SBX to sea and in position (it's not exactly a speedboat), and the best orbital conditions for the shot. The location was almost certainly based on the SBX being in Hawaii and having nice long empty stretches of ocean downrange for the SM-3 missile. (Both for the booster and for the payload to fall if it misses.)
The thing's low enough that all of it -- intact or in pieces -- will deorbit soon (days to weeks). And actually, smaller debris deorbits faster; there's more surface area per volume (and hence per mass), so drag from the not-quite-vacuum of the upper atmosphere decelerates small pieces faster.
When all you have is a hammer, everything looks like a skull.
obviously its just the government in a pissing contest with china.
its not like there are pesky differences between the two, like one was in high orbit, one is about to enter the atmosphere with toxic cargo and the potential to kill people if it lands in the wrong area.
...and the date has been confirmed
Actually, it doesn't. Orbital mechanics guarantee that the debris will pass through the same altitude one orbit later.
That's certainly believable if you can take Deputy National Security Advisor James Jeffrey at his word:Apparently man-made objects containing hydrazine propellant frequently rain down from the sky without incident, according to rocket scientists and space security experts who "scoff" at this rationale. And Joint Chiefs of Staff Vice Chairman Gen. James Cartwright doesn't seem too impressed either. But surely our Deputy National Security Advisor knows something about hydrazine that we don't.
Now who is this man James Jeffrey, you may ask?Source: Wall Street Journal, July 19, 2007, four months before the information in the Iran NIE would be exposed, having been known to the White House since 2006.
This guy sounds totally not full of shit at all!
John
The reactors sent into orbit are supposedly built to withstand re-entry and a crash landing. Firing explosives at a reator in LEO and potentially spreading fairy dust everywhere is probably worse than letting it form a crater in the ground where contamination can be contained.
Regardless of the 'real reason', shooting down the hydrazine is a GoodThing(TM).
And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
Spy satellites (or any imaging/mapping sats) are usually in very circular orbits. Otherwise your image resolution gets degraded for most of the orbit (because you're farther away) and you have to constantly keep track to figure out what the actual resolution IS. As you pointed out, atmospheric drag tends to circularize things as well.
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.
Sometimes I doubt your commitment to Sparkle Motion.
It doesn't work that way. Nothing manmade reenters all in one place and leaves a "crater". Debris generally gets scattered along a trail across a thousand miles or two in chunks.
Sometimes I doubt your commitment to Sparkle Motion.
Well spirals are orbits, but ones which are perturbed by air resistance. If you ignore air resistance (and relativistic effects), then yes, all orbits would be perfect ellipses (or hyperbolas). In this case, the orbits of any debris will pass through the point of the explosion again, discounting air resistance. In reality, they will pass even lower, due to air (and in many cases, ground) resistance. They only way they could attain a stable (that is, higher than significant air resistance) orbit is if half an orbit after the explosion, they get kicked forward again.
First off, the US has NEVER claimed to be the "...immaculate custodians of space..." like you claim.
Second off, regarding the Delta II second stage, it was believed based upon its size, speed, trajectory and form that it would burn up on reentry so the belief was we were OK. We know for sure that the satellite will survive reentry so we are trying to be proactive.
Do we allow toxic material to reenter, Yes. Do we believe based upon size, speed, trajectory and such that the material will burn up, Yes. Can we send up a missile on everything that is reentering our atmosphere, No. At least we are trying (for whatever reason you want to believe) as compared to other nations so please take off the tin foil hat so your head can get a little air in hopes it allows you to think just that much more clearer.
...why not build satellites with standard self-destruct for cases like this? First, a self destruct mechanism would add mass to the satellite, which takes mass away from other gear you'd like to add.Secondly, if your satellite is not functioning, like this one, how would you activate the self-destruct mechanism?*
A possible third is security. What if "the enemy" were to get a hold of the self-destruct codes for all of our satellites? Shooting down a satellite with a missile is a much more costly and traceable event than sending out a radio signal and quietly killing them as they pass overhead.
*I can think of ways to do this, with pressure and temperature sensors to detect a decayed orbit or an entirely redundant receiver and power supply, but you're really adding mass here. For the extra mass to launch or the reduced capability of the satellite, it may be cheaper to just shoot down birds that don't work.
If you want a vision of the future, imagine a youtube comments section scrolling - forever.