Defunct Spy Satellite Falling From Orbit 312
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."
Re:Peru? (Score:5, Informative)
Actually, those hazardous materials were all natural and already in the ground: Meteor Crash in Peru Caused Mysterious Illness [nationalgeographic.com]. Noxious fumes created by hot meteor smashing into arsenic-tainted water.
here it is (Score:5, Informative)
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 [wanadoo-members.co.uk]
http://mysite.wanadoo-members.co.uk/satcom_transits/193bw.jpg [wanadoo-members.co.uk]
Note, no solar panels.
Comparative Characteristics of Imagery Satellites (Score:3, Informative)
Example: The Lacrosse satellite [wikipedia.org] (KH-12 is the other designation) weighs 14-16 tons.
"Lacrosse and Onyx are the code names for the United States' National Reconnaissance Office terrestrial radar imaging reconnaissance satellite. While not officially confirmed by the NRO or anybody in the U.S. government, there is widespread evidence to confirm its existence."
"Due to overruns, the cost of the Lacrosse-1 radar reconnaissance satellite launched in 1988 from the Space Shuttle exceeded $1 billion. In the opinion of experts, it was designed, above all, to search for mobile launchers for Soviet ICBM's and track strategic weapon systems beyond staging bases. The radar images were transmitted to the processing center via TDRS repeaters located under the management of NASA and deployed in a geostationary orbit. The Lacrosse-2 was launched in 1991 using a Titan-4 booster rocket from the Western Missile Test Range, which made it possible to increase the orbit inclination and, consequently, the zone of coverage from 57 to 68 degrees."
Note (Score:5, Informative)
see the following note from him:
http://www.satobs.org/seesat/Jan-2008/0204.html [satobs.org]
Re:Jesus... (Score:5, Informative)
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.
Re:why do we care (Score:5, Informative)
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 details (Score:5, Informative)
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.
Cosmos 954 cleanup with computer technology view (Score:1, Informative)
The Canadians had a Nova minicomputer which was subjected to conditions that it was never designed for. They programmed it by editing memory locations by hand... Not with the front-panel switches, even though Nova had those.
Re:why do we care (Score:2, Informative)
It's a function of things like the heat of ablation, suface area and mass relationships, and where in the spacecraft the object begins.
Rocks like to break up into lots of little things with reasonable heating areas and masses; satellites not so much. Ti bolts don't like to go because of low heating area and high ablation temps. Ti Fuel tanks don't because they again don't ablate, have high area to low mass which makes it less likely to go because they come down slower, and the rest of the sat has to go before it starts to heat. The mirrors and lenses are similar.
Re:Jesus... (Score:5, Informative)
Re:Jesus... (Score:1, Informative)
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.
(Now using the preview button)
Re:Oh, horsecrap! (Score:3, Informative)
Realistically, there's exceedingly little danger to anyone on the ground. MOST spacecraft launched into low orbits, upper stages, etc, have burned in uncontrolled over the years, with negligible effect, even Skylab which was far larger.
BTW the likely "hazardous" materials are no different from the shuttle - hydrazine, nitrogen tetroxide and maybe a high-pressure gas bottle or two. If it has an RTG, the only danger is that its going to make it do the ground intact and become another heavy projectile. Typically they are designed to do exactly that, just so they have no chance of releasing radioactive materials. The chances are nearly *zero* that the containment will fail. It's more likely that a guy will get hit by a meteorite on the way to pick up his lotto winnings. The shuttle came down over the south-central US with no injuries on the ground, and it has 5x the parts.
Brett
Better link (Score:5, Informative)
Re:The size of the Hubble? (Score:3, Informative)
The objective is to estimate wavefront distortion along the viewing path caused by "atmosphere." These distortions are compensated for by a deformable mirror (and usually a tip-tilt mirror). But I do not believe that you can do better than what is predicted assuming diffraction limited optics... I will have to pull out my Tyson book to check. (Or rather, someone else can...)
There are algorithms that use blind deconvolution to "back out" a less blurry image, but (I think) it is a statistical method requiring several frames and an estimation of the point spread function of the system. It does not make the optical system any better by changing its spot size. An adaptive optics system effectively moves the PSF closer to the diffraction limited size, but not smaller.
Really cool technologies, which I have very limited knowledge of. If AO has strong research support, please let us know. Because I have wanted to work with such systems for a while now...
Re:why do we care (Score:2, Informative)
Re:Jesus... (Score:3, Informative)
It may have lost power and thrust from hardware/software failure, not because it ran out of something. Not that spooks are the brightest people, but I would think if they were down to the last bit of fuel they would use it to de-orbit intentionally.
Re:Nuclear Powered = Plutonium (Score:4, Informative)