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Defunct Spy Satellite Falling From Orbit
dnormant, among other readers, sent us word that a US spy satellite has lost power and propulsion and could hit the Earth in late February or March. Government officials spoke on condition of anonymity because the information is classified as secret. None of the coverage speculates on how big the satellite is, but Wikipedia claims that US spy satellites in the KH-11 class, launched up to the mid-90s, are about the size of the Hubble — which is 13 meters long and weighs over 11,000 kg. "The satellite, which no longer can be controlled, could contain hazardous materials, and it is unknown where on the planet it might come down... A senior government official said that lawmakers and other nations are being kept apprised of the situation."
That will be USA 193 (06-057A, #29651). This is it's current orbit:
USA 193
1 29651U 06057A 08022.26925691 0.00105000 00000-0 21306-3 0 07
2 29651 58.5247 160.3977 0003288 53.6760 306.3240 15.98950761 06
Lowest point is about 275 km above earth surface currently.
This under the right conditions is an easy to see object: it can reach magnitude
+1 and because of its low orbit is very fast, spectacular to see.
source: Marco Langbroek
picture in orbit:
http://mysite.wanadoo-members.co.uk/satcom_transits/USA193Sepbw1.jpg
http://mysite.wanadoo-members.co.uk/satcom_transits/193bw.jpg
Note, no solar panels.
It could be worse, it could be Monday.
John added the solar panels in the first image.
see the following note from him:
http://www.satobs.org/seesat/Jan-2008/0204.html
Posting as AC for NDA reasons.
It's common knowledge in NASA that lots of US satellites are nuclear powered. It's actually not that dangerous, if it blows in re-entry it will go over a big enough area to just fade into the background radiation, and if it comes down in one piece they can go gather it up. However, people are so worried about such things they would never admit it. This "may contain dangerous materials" is the closest you'll ever get to an admission.
Hardly surprising, since "in the ocean" means 80% of the Earth's surface...
To put this in perspective, consider that over thirty thousand meteorites have been found on the ground. There's one in Oregon that weighs sixteen tons; the rate of impacts, found and unfound, has been estimated at 500 per day worldwide.
Know anybody who's been hit?
Actually, a few people -- a very few -- have. The surface of the Earth is a big place, and not a very big fraction of it is covered by people.
rj
KH-11 series spacecraft were called the Key Hole satellites - they were the first large reconnaissance spacecraft to send images directly to earth; previous spy satellites used film return (clumsy, slow, and unreliable). KH-11's used CCDs - quite advanced for a system developed in the late 1970's.
The seven KH-11 spacecraft had primary mirrors of 2.3 to 2.4 meters. The system provided an ultimate ground resolution between 15 to 50 cm at closest approach (perigee); actual resolution was quite a bit worse.
There's no nuclear battery on board -- power came from 11 unfolded solar panels (which, on the first Key Hole satellites didn't provide quite enough power during downlinks!). I assume the main danger to earthlings is due to the reentry of the main mirror. Since the KH-11s are in polar orbits, the debris could come down anywhere on earth, with a one-in-four chance of hitting land.
The KH-11 spy satellites were developed in parallel with the Hubble Space Telescope, and the same contractors worked on both. In fact, the KH-11 uses much the same hardware (carbon-graphite support system, front door hatch system, data-relay dish through communications satellites). Because of the secrecy surrounding the KH-11 development, the Space Telescope project often saw similar secrecy. Indeed, astronomers were discouraged (or barred) from much of the engineering of the Hubble Space Telescope.
Your post contains the sort of interesting truths and half-truths from which conspiracy theories grow. I'll try to add to the true parts while keeping things interesting. The US does currently have several nuclear powered space vehicles, all of them deep space missions and all of the powered by RTGs. (Voyager I/II, Poineer I/II, Cassini, New Horizon, etc) RTGs are different from reactors in that they are passive devices relying on spontaneous isotopic decay and therefore have a fairly constant (but decreasing) power output. Reactors meanwhile have a feedback loop controlling the energy and number of neutrons available to initiate fission and so have variable power output. The reasons RTGs are used for deep space vehicles are that they're economical and simple. Because of the pesky inverse square law for illumination intensity solar panels start becoming more expensive than RTGs somewhere around the asteroid belt. Relative to fast reactors like SNAP-10 and the Russian TOPAZ RTGs are child's play and dead safe. RTGs are also much less harmful in the case of a launch accident since the plutonium oxide fuel is an alpha emitter and is encased in metal anyway. The US has only launched one satellites a nuclear reactor, SNAP-10A which was expensive and only lasted 43 days. Since it was unreliable in addition to being horrendously expensive the US stopped pursuing reactors in space since since other technologies were better fits. Fortunately for us the Russians probably thought we turned it into a black program and started furiously testing nuclear reactors on satellites. Consequently the Russians have the most experience with reactors in space since they have launched over 30. If we ever need a space craft with over 100KW of power where reactors become cost effective I'm sure we'll be looking at their designs.