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Is LEO too Crowded?
February 11, 2009 3:48 PM   Subscribe

"They ran into each other. Nothing has the right of way up there. We don't have an air traffic controller in space. There is no universal way of knowing what's coming in your direction." An unprecedented collision of two orbiting satellites yesterday highlights the increasing threat of space junk.
posted by Chinese Jet Pilot (51 comments total) 6 users marked this as a favorite

 
Huh, I was wondering why my long-distance call to Irkutsk was cut off.
posted by mr_crash_davis mark II: Jazz Odyssey at 3:50 PM on February 11, 2009 [1 favorite]


Cleanup on aisle sexvigintillion and three.
posted by weapons-grade pandemonium at 3:56 PM on February 11, 2009 [3 favorites]


Actually, I'd thought that every sliver of junk in orbit was very thoroughly tracked. But I haven't read TFA.

I'm actually very sympathetic to the aerospace-industrial complex, aside from it being the most wasteful and overly political piece of doodoo to ever plague the western world. We(mankind!) could have reached the moon, mars, and launched thousands of satellites at a lower price. Since mankind can't do anything without crooks standing in the way, my perception of our existence is perhaps more dismal than it ought to be.
posted by christhelongtimelurker at 3:57 PM on February 11, 2009 [1 favorite]


I applaud this news, if only because objects in space crashing into one another paves the way for the eventual formation of a Space Hulk.

My genestealers are ready.
posted by Parasite Unseen at 3:59 PM on February 11, 2009 [2 favorites]


I just watched a Wired Science episode where the covered the costs involved in building geostationary satellites, launching them, and reserving "space" for them to orbit (orbits much, much higher than those mentioned in the article). The orbital position is millions of millions of dollars and controlled by the International Telecommunication Union.

The whole show made me wish an upstart little nation would allow some eccentric mega-billionaire to launch his own satellite into that orbit and just smack everyone else's satellites down into the ocean.
posted by Science! at 4:06 PM on February 11, 2009 [1 favorite]


Have there been proposals on ways to clean up all this orbiting junk?
posted by R. Mutt at 4:09 PM on February 11, 2009


I'm also no satellite "apologist", clearly something going on here. But from a strictly data visualization POV, something seems off in those pictures from the second link. For an article coming from a scientific perspective I didn't see any sign on whether these were "artist interpretation" or diagrams made to scale.

Doesn't really make their argument stronger to leave this part out . . .
posted by jeremias at 4:09 PM on February 11, 2009 [1 favorite]


Actually, I'd thought that every sliver of junk in orbit was very thoroughly tracked.

Yes and no. They try but there are many problems, not the least of which is even being able to tell things apart.

In order to define an orbit, you need to see the same object multiple times. How many observations you need depends on the separation in time and space, whether you are looking with radar (and thus getting range directly) vs optically, etc. But when you get multiple observations, how do you know which ones are "the same object"? In order to call N observations "the same object" you need an orbit that flies through them all (and precisely enough to exclude fellow-travellers). But in order to get that orbit, you need to consider those N together. Chicken and egg.

There are many heuristics and shortcuts and optimizations, but it's still a huge hairy problem and, from what I've heard, the ones in charge of solving it are kind of bogged down. And of course when collisions do happen, the problem gets worse--now you have more debris! Plus the now-smaller pieces are harder to see than the original object.
posted by DU at 4:09 PM on February 11, 2009 [1 favorite]


...diagrams made to scale.

The number and position looks realistic but the satellite size is hilariously exaggerated. If you zoom in, some of those LEO sats are bigger than Europe.
posted by DU at 4:11 PM on February 11, 2009


American satellite: "Commercial" = capitalist pig dog.
Russian satellite: Drunk
posted by Artw at 4:19 PM on February 11, 2009 [1 favorite]


reserving "space" for them to orbit

This refers to geostationary satellites, which necessarily orbit above the equator. The "space" is the longitude along the equator above which they sit. They're regulated by the ITU because they're mostly communications satellites; direct tv, satellite radio, etc. The two satellites involved in this collision were not geostationary satellites, and hence the mechanics of the orbits become much more complicated. There's no simple way to allocate "non-colliding orbits" for satellites on inclined orbits.
posted by kiltedtaco at 4:29 PM on February 11, 2009


Damn, are we gonna have to bail out SPACE next?!
posted by jamstigator at 4:32 PM on February 11, 2009 [3 favorites]


So, basically, in addition to the strewn oxygen bottles and human bodies at the top of Everest, mankind has trashed the immediate vicinity of the planet as well.
posted by Mental Wimp at 4:49 PM on February 11, 2009 [1 favorite]


Clearly this was the first stage of a russian attack!
posted by Sargas at 4:49 PM on February 11, 2009


Unprecedented? Nope. Last year, XM and Sirius merged and, according to yesterday's news reports, the prognosis is grim.
posted by grounded at 4:58 PM on February 11, 2009 [1 favorite]


My understanding is NASA tracks items in space for impacts against their gear's orbit. Which is a huge job.
Tracking every item against every other item's orbit would be a many orders of magnitude bigger job, and probably close to impossible.
posted by bystander at 5:00 PM on February 11, 2009


Russians? Peh! It's China's turn to glare at the US from the heavens.
posted by filthy light thief at 5:03 PM on February 11, 2009


In an unprecedented space collision, a commercial Iridium communications satellite and a defunct Russian satellite ran into each other Tuesday above northern Siberia

Uh-huh. "defunct Russian satellite". Riiiiiight. Seriously don't need a tinfoil hat for this to scream SPY SATELLITE.
posted by amuseDetachment at 5:03 PM on February 11, 2009 [1 favorite]


That said, I would understand the odds of this kind of collision occurring are vanishingly small (two 'big' orbital bodies colliding). Small to the point where it wouldn't hurt to be a bit suspicious.
I personally believe it was a James Bond-esque space fight.
posted by bystander at 5:06 PM on February 11, 2009


Oh, and considering that this occurred above Siberia: Iridium, a "global satellite communications network" would be an awesome place to hide spy satellites. "Uhm... that's just telecommunications equipment there".
posted by amuseDetachment at 5:12 PM on February 11, 2009


Space Junk
posted by The Whelk at 5:16 PM on February 11, 2009


OK, so take these pictures of all that the junk in space, and imagine a line going all the way through them, out past geosynchronous orbit. That would be the proposed space elevator, standing still above one point, and so sweeping through most of those orbits. And not just junk, functioning satellites as well.

That's the big problem with the space elevator, that nobody even wants to address: the space it's going to be put up through already has stuff moving through it.
posted by happyroach at 5:16 PM on February 11, 2009 [1 favorite]


Wait, Iridium is still in business?
posted by UrineSoakedRube at 5:26 PM on February 11, 2009


Yup.
posted by longdaysjourney at 5:40 PM on February 11, 2009


This is exactly like the story the main character would see on TV in a movie about a secret military operation to take out a vital communications satellite, just before they flicked it off mid-sentence and threw the remote at the wall, smashing it. Cut to closeup of wheels spinning, then gripping, as protagonist zooms off to see their hacker friend.
posted by odinsdream at 5:40 PM on February 11, 2009 [1 favorite]


That's the big problem with the space elevator

Aw, why'd you have to blab? If you hadn't brought up that minor "satellites crashing into it constantly" issue, there wouldn't be any other conceivable flaws in that otherwise tip-top concept. Way to blow it for everyone!
posted by Sys Rq at 5:50 PM on February 11, 2009


Oh, and considering that this occurred above Siberia

Russia is pretty far from the equator, has a lot of longitude to cover and geo sats are expensive. So they worked out their own unique set of orbits which are these really long, looping things that goes way out beyond LEO on one end and then skims along the Earth on the other end. The orbit basically hangs above Russia for hours at a time, kinda simulating a geo sat, and then screams past...whatever's the antipode of Russia. Neither of these locations is going to be highly populated because of the odd altitude, but it has to zoom through the LEO "belt" on the way through. Just guessing, but I bet "Siberia" is right about where it hits that belt.
posted by DU at 5:59 PM on February 11, 2009 [3 favorites]


Clearly we need Superman to go up there and toss all that junk into the sun.
posted by bwg at 6:01 PM on February 11, 2009


There's one other problem with tracking space debris in LEO: atmospheric drag means low orbits are unstable, and the smaller (in mass-to-volume ratio, which correlates linearly with length) an object is, the less stable it's orbit is. This is good for getting rid of space junk, because most of it is small bits and pieces which will deorbit faster than the satellites we don't want them to crash into. But it's bad for tracking space junk, because even if you manage to track a precise position and velocity at one point in time you still need to keep tracking it closely as its orbit changes. The changes depend on one aspect of space "weather", the expansion and contraction of the outer atmosphere, and so aren't entirely predictable in advance.

That's the big problem with the space elevator, that nobody even wants to address: the space it's going to be put up through already has stuff moving through it.

Actually, everybody's already addressed it. You dodge trackable satellites by moving the elevator (it naturally moves slightly to the side as you bring up payloads, and you can control the position by changing payload timing). You repair damage from small space junk in the same way you expand payload capacity, by regularly bringing up new fibers to replace and add to old ones in a redundant cable/ribbon design. Those solutions might not work well enough, and in fact the whole dream currently still depends on cheaply mass-producing unobtainum, but it's not like you're the first to realize there's a problem.
posted by roystgnr at 6:12 PM on February 11, 2009


I would like to volunteer to be the Earth's first space janitor.

All I'd need would be a berth on the ISS, and the space equivalent of a jetski. Find the garbage, get a good visual, and give it a healthy shove towards the Earth.

You get clean spaceways, and a lovely regular light display.

I get to live in orbit.

It's a win-win.

Please see attached resume.
posted by MrVisible at 6:24 PM on February 11, 2009 [4 favorites]


Is anybody concerned that Iridium Satellite is a LLC? I mean really, a satellite company with a LLC status?
posted by captainsohler at 6:29 PM on February 11, 2009


Thank God all this crazy space shit seems to happen over Siberia.
posted by Corduroy at 6:34 PM on February 11, 2009


Actually, this fills me with hope.

My oft stated desire is to exit this life as a victim of space debris. Already, I missed my chance when the shuttles blew up, but now, if I can just get into low earth orbit, (when the time comes, of course), I may yet stand a chance!
posted by FauxScot at 6:38 PM on February 11, 2009


NASA's World Wind has an add-on for arm chair (desk chair...?) satellite tracking....
posted by Kronos_to_Earth at 6:40 PM on February 11, 2009


DU: Nope, Cosmos 2251 and Iridium 33 were both in circular orbits, not Molniya.

Incidentally, if I'm reading those orbital elements right, the satellites would have to have collided at about a 102-degree angle (i.e. almost a right angle, slightly head-on) which means the relative velocity was something like 11.6 km/sec. Honestly, I'm a little astonished there's any debris left to track.
posted by teraflop at 6:44 PM on February 11, 2009 [2 favorites]


776 x 799 km, 74.0°

What is that, apogee x perigee + inclination?

I work with orbits every day and I'm still always amazed by the predictions that site can make. That said, I tried to spot an Iridium flare once and saw nothing. (A guy I work with says it's like "a police helicopter spotlight" when you see it, so presumably I should have noticed.)
posted by DU at 7:23 PM on February 11, 2009


Where is a good place to start learning about orbits?

That was the last thing I studied in mechanics before we moved to electricity and magnetism in college, and I've since had the feeling that I am missing out on some really cool stuff.

I took a very basic astronomy class once, and we saw an Iridium flare. The professor, a professional astronomer, spent about 2 hours on his laptop setting up a computer controlled tripod kind of thing with a bright laser to get it to point in the direction of the flare. It was short and intense, but nowhere near a helicopter spotlight. I've never been able to see another one, and thus my plans of founding a UFO cult based on "commanding" those flashes of light to happen when and where I say remain incomplete.
posted by dirty lies at 7:53 PM on February 11, 2009


"But you, I think, can imply that the majority of that should be probably along the same line as the original orbits."

Okay, I've taken enough grammar dweeb beatings to know that not many people care about this, but for the love of christ, I've heard enough people use infer instead of imply, but this is the first time I've heard the reverse. Is everyone trying to buy me a bill of goods? You can buy it to me all day; I'm not selling it from you.
posted by Turtles all the way down at 7:55 PM on February 11, 2009 [1 favorite]


Sucks for Iridium. I don't suppose they can by insurance for something like this.
posted by various at 8:27 PM on February 11, 2009


dirty lies,

Try here.
posted by lukemeister at 9:17 PM on February 11, 2009 [1 favorite]


I mean really, a satellite company with a LLC status?

A lot of larger-than-you'd-think companies are LLCs or LLPs now. The main reason is that a C Corp is taxed as a business and as income to its owners, while an LLC is taxed only once because it's a pass-through.

I don't suppose they can by insurance for something like this.

It does look like they can, but it may be less expensive in the long run to just have backup satellites either on orbit or near launch. Iridium has more depth than any other satellite owner just because of the size of its fleet.

Wait, Iridium is still in business?

Not the original Iridium, no, but the company that bought the assets for pennies on the dollar instead of millions of risky investment in actual launches seems to be doing fairly well. The market was never large enough for the first business model to work, anyway, but now it's subsidized by the Pentagon.
posted by dhartung at 10:26 PM on February 11, 2009


dirty lies: If you want to really get how spaceflight works, I can't recommend Orbiter highly enough. Sadly, it's for Windows only.
posted by teraflop at 10:37 PM on February 11, 2009


If you really want to get your hands dirty with taking actual observations and making orbital predictions, try these guys.
posted by DU at 3:03 AM on February 12, 2009


What happens to this stuff that "burns up" upon reentry? Doesn't that introduce metals to our atmosphere? Is it just that it happens in such small amounts (relatively) that it doesn't have a large environmental impact?
posted by Eideteker at 7:37 AM on February 12, 2009


Is there any way armchair observers can guess as to the odds this was actually an accident? It seems equally likely that it was a demonstration of Russian military capability, following on last year's missile demonstration by the Chiense. I don't have a good feel for the odds of a collision like this happening at random. If they're really orbiting at right angles it seems that the odds of a random collision are vanishingly small.

Here's another story on the event (with no suggestion of deliberate Russian military action).
posted by Nelson at 8:37 AM on February 12, 2009 [1 favorite]


Actually, I'd thought that every sliver of junk in orbit was very thoroughly tracked.

They try, they try. Presumably other countries do also.

Guess they missed one, or weren´t inclined to tell the Russians about it. Can you even steer one of those things if it is apparent there´s going to be a collision?
posted by yohko at 9:59 AM on February 12, 2009


DU, teraflop and lukemesiter: Thanks for the links.

Now I have another question for you: How many and what kind of flowers should one give one's wife when one ignores her for a weekend? I want to be prepared.
posted by dirty lies at 3:33 PM on February 12, 2009


dirty lies,

Since Saturday is Valentine's Day, do you think you could wait until Sunday to start exploring orbital mechanics?
posted by lukemeister at 9:04 PM on February 12, 2009


Oh, and considering that this occurred above Siberia: Iridium, a "global satellite communications network" would be an awesome place to hide spy satellites. "Uhm... that's just telecommunications equipment there".

No. In low earth orbit, you circle the entire earth every hour and a half. It's just a coincidence that it happened over Siberia.

(That is, unless it was a Russian ASAT that hit the Iridium satellite, which is a bit paranoid. Wouldn't you think that the Pentagon would go public with that? Another excuse to beat the drum...)
posted by justsomebodythatyouusedtoknow at 11:17 AM on February 13, 2009


Kaputnik chaos could kill Hubble
posted by homunculus at 4:34 PM on February 18, 2009


... but now it's subsidized by the Pentagon.

Hmmmmm.
posted by Sys Rq at 4:38 PM on February 18, 2009


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