Speculation On the Doomed Satellite 229
scim writes "Intelligent speculation has led one knowledgeable observer to believe the satellite recently announced to have failed is a radar satellite named USA 193. According to an earlier story on the satellite: 'The experimental L-21 classified satellite, built for the National Reconnaissance Office at a cost of hundreds of millions of dollars, was launched successfully on Dec. 14 [2006] but has been out of touch since reaching its low-earth orbit.'" The ArmsControlWonk story leads off with what purports to be a photo from the ground of USA 193.
Re:Only one man would use the strawberry... (Score:2, Informative)
It's raspberry for ***** sake!
Re: (Not in) My Backyard (Score:5, Informative)
Recall that some of our older satellites had Polonium 210 coatings applied to some surfaces which could not be allowed to become frozen (batteries, etc.) in the deep cold of space (including parts of our Apollo Lunar Rover if my memory serves). http://en.wikipedia.org/wiki/Polonium [wikipedia.org]
Wait a minute!!!, Wasn't this the secondary plot to G.I. Jane?
Your Nerd License is hereby revoked (Score:3, Informative)
Re:Which is it? (Score:5, Informative)
Most likely:
a) its solar wings failed to deploy
b) it is therefore in deep sleep
c) what goes up (and remains within the Hill Sphere) must come down
ymmv
Re:Will it burn up? (Score:5, Informative)
Most of it will burn up on reentry. Depending on how large it is and the materials used, there will probably be many small pieces of debris reaching the ground across hundreds of miles.
Which brings me to something else: do these satellites have some sort of self destruct mechanism? What was to stop, say, the Soviets or Chinese from going up and physically stealing a very expensive satellite that presumably contains technology/information we don't want them getting their hands on?
The same thing that stops them from say seizing a US ship somewhere on the ocean and ripping out its radar and other technology. Its piracy and it would invite if not all out war then at least some sort of major retaliation by the US.
Re: (Not in) My Backyard (Score:4, Informative)
This was the first thing I thought of when I read the same story at BBC News [bbc.co.uk]. But that article says the fuel is hydrazine.
(But as the source was anonymous, and the satellite is US Military, that leak could just be a PR move !!)
Re:Will it burn up? (Score:3, Informative)
Re: (Not in) My Backyard (Score:5, Informative)
Re:Bad design... was it made in china? haha (Score:2, Informative)
Re:Enough already (Beware Al Queda Humorists) (Score:3, Informative)
bzzt (Score:3, Informative)
It's not clear, however, why a satellite in a highly elliptical orbit would use RTGs instead of solar panels. It's not like it gets a lot of stealth that way, since apparently it's still very visible by radar and even telescope.
Re:My Backyard (Score:4, Informative)
I suppose I wasn't clear on the details.
Hydrazine is more flammable than gasoline, by a wide margin. Flammability limits in air are approximately 2% to 100% -- It's a monopropellant, so it doesn't actually need oxygen to burn (it's a fuel, though, so it will burn faster and hotter with oxygen). That makes it more flammable than even hydrogen. Fortunately it has a lower vapor pressure, so the flash point is somewhat elevated. As a fire hazard, I'd call gasoline worse, but hydrazine is plenty bad enough.
Hydrazine is explosive by itself, without any additions of components. However, it's relatively insensitive, so this is really only a concern to industrial handlers, not to someone who finds a satellite crashed in their yard.
Hydrazine is toxic well beyond the level of bleach. LD50 for skin contact is somewhere around a teaspoon -- a fairly minor spill. At levels well below that, it will cause *permanent* damage to your liver, kidneys, and probably others. There's nothing in your house where a small splash on your skin warrants a trip to the ER (and if there is, you must have some neat hobbies!).
Hydrazine isn't as caustic as some household cleaners; this is mostly relevant when engineering with it, not for hazards of encountering it. It does mean it will eat away many sorts of gloves you might wear -- which makes the previous point and the next three relevant.
It's not just that hydrazine is carcinogenic. Lots of things are carcinogenic in large quantities; a few are in any quantity. Hydrazine is one of the latter (obviously risk level depends on exposure). Some chemicals your body can safely metabolize small amounts of without any increased risk; hydrazine is not one of these. What makes hydrazine so nasty is that, combined with the degree of potency. Monomethyl hydrazine (I don't have data handy for straight hydrazine, which is less nasty; the satellite could well be using straight hydrazine as a monopropellant or MMH or UDMH as a fuel in a bipropellant; all three are commonly used) is one of the most potent carcinogens known. One study showed that a carefully sized single drop of MMH on the skin of lab rats caused cancer in 90%. They had to be careful to keep the drop size down so that it didn't kill the rats by being toxic, though.
Mutagenic and teratogenic are nasty at similar levels; the effects are just slightly different than being carcinogenic. Planning on having kids you want to be healthy? Don't handle hydrazine derivatives.
Now, all that said, with sufficient budget and in the right setting it can be handled mostly safely. "Some thing landed in my backyard; I think I'll get a souvenir" is not that setting. And, depending on the design of the satellite, it's entirely possible a mostly undamaged propellant tank could survive reentry -- similar components have done so previously on other satellite reentries, and on Columbia.
You're surrounded by low level background risks, and things that you shouldn't drink. Hydrazine goes well beyond that -- you'd do better to think of it as a chemical weapon that happens to be to slow to be useful as such. It's only mildly less potent than some of them.
Re:Enough already (Score:4, Informative)
And I have to ask, how exactly are you supposed to defend yourself if you're not charged with anything?
PS: <sarcasm>They do have a lawyer, don't they?</sarcasm>
Re:Tracking the orbit (Score:2, Informative)
http://www.heavens-above.com/orbitdisplay.asp?satid=29651&lat=48.59562&lng=2.92156&loc=Somewhere&alt=10&tz=GMT [heavens-above.com]
Change lat / long as appropriate.