9 Ideas For Coping With Space Junk 149
An anonymous reader writes "The space age has filled Earth's orbit with all manner of space junk, from spent rocket stages to frozen bags of astronaut urine, and the problem keeps getting worse. NASA's orbital debris experts estimate that there are currently about 19,000 pieces of space junk that are larger than 10 centimeters, and about 500,000 slightly smaller objects. Researchers and space companies are plotting ways to clean up the mess, and a new photo gallery from Discover Magazine highlights some of the proposals. They range from the cool & doable, like equipping every satellite with a high-tech kite tail for deployment once the satellite is defunct, to the cool & unlikely, like lasers in space."
Hit or Miss (Score:5, Insightful)
That Discover article was pretty hit-or-miss. They nailed the real solution in two of their pieces (tethers and sails), in that the best (easiest, cheapest, only-one-that-will-probably-ever-happen) are technologies that are built into space objects (satellites and boosters) before launch. There's lots of options here from tethers, sails, balloons [slashdot.org], or just using existing thrusters. If we can stop leaving big pieces up there (which can run into other big pieces and make LOTS of pieces), the problem will start getting less severe.
On the other hand, on of Discover's pages was about blowing up the debris...this makes sense, until you really think about it. The problem is that when you blow up something, it makes a huge number of new pieces, with all sorts of different velocities and orbits. On average, these pieces will fall to earth more quickly than the unexploded satellite, however, that's just the average. There are many pieces that will stay up there even longer. And when you're talking about things moving that these incredible velocities, it doesn't matter a whole lot if you get hit by a 6,000lb. satellite or a 5lb. piece of a satellite, either one will destroy anything we've put in orbit.
Re:Hit or Miss (Score:5, Interesting)
So what else did the article discuss? Well it mentioned the Kessler effect, which has nothing to do with dealing with space junk, but is just a model used to describe space junk. It mentioned that NASA is now putting more efforts into tracking space junk. This is important, of course, but doesn't qualify as a method for removing it or handling it (excepting the very indirect means of simply avoiding it). Then it talks about shielding spacecraft from space junk. This, of course, is necessary and current practice, but no amount of shielding (presently) will protect you from detached thermal blankets or burnt out Delta stages.
All in all, this article just seemed like a disorganized, loosely-themed, terse ramble. I usually expect better from Discover but was severely disappointed in this particular release.
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the tool kit dropped by astronaut Heide Stefanyshyn-Piper during a spacewalk in 2008
That tool kit re-entered the atmosphere in August of 2009. http://en.wikipedia.org/wiki/Heidemarie_Stefanyshyn-Piper#Lost_tool_bag_during_spacewalk [wikipedia.org] Come on guys. Do some fact checking.
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I wonder at the effectiveness of putting a very large focusable solar reflector in a high orbit, perhaps at LaGrange point 1. Such a solar sail could be used to give thrust to satellites equipped with a sail, or even large bits of space junk. Obviously it wouldn't give much Delta V to junk, but it might give some, and it would be essentially free. Junk in high orbits takes hundreds or thousands of years to de-orbit, and any means of reducing the velocity of said junk would drastically reduce that time. Addi
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This could realistically point at a very small number of targets in a given amount of time, for quite little average effect above what the Sun can already give...
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Usually we do have to limit ourself when it comes to sizes / numbers though; and solutions compete with each other to the death. When times will come that we won't have to...well, that means ability to deal with debris in via more "active" measures anyway, for example.
Generally, I suspect that either a) tracking would be too slow to target appreciable number of targets, or b) (when modulating reflectivity / "wide area" focused) the effect would be miniscule compared with what the Sun already provides (espec
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Remember how extremely precise the tracking would have to be & without introducing structural instability to, preferably, very lightweight mirror - which on top of that is the biggest solar sail present, by far (so with a massive need to stationkeep / combat momentum, depending on the variant). Small dish under immense energy flux onto its fairly imperfect (remember, certainly space weathered) surface.
As for prolonging times of some solar powerplant (if there was any time left for that) - a semi-orbit a
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That's what you get from reading TFA...
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You'd mostly get a cloud of ionised particles interfering with / destroying satellites. And since when America cares about affordability of silly pursuits?
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> like equipping every satellite with a high-tech kite tail for deployment once the satellite is defunct ... which increases the mass and size of the satellite, which increases the spalling damage if it does get hit by debris. I'm not convinced this is a good idea.
Maury
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Size - yeah, that's the idea. But it's mostly a size of thin sheet, not such a problem when hit. Mass - only slightly.
Drastically increasing drag-to-mass ratio.
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Roger that! 10-4 good buddy; over and out!
Sincerely,
Me
Dictated but not read
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On the other hand, on of Discover's pages was about blowing up the debris...this makes sense, until you really think about it. The problem is that when you blow up something, it makes a huge number of new pieces, with all sorts of different velocities and orbits.
Most problems with lasers can be solved by higher power lasers. Just increase the power output and decrease the delivery time until you can turn any debris you target completely into gas or plasma. For larger objects, target a non-rotating point so it'll turn to gas and push the object out of orbit.
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Yes, and the first layer of ionized atoms will scatter the rest of the laser energy, and push on the object... Sigh, you Space Loons are a big, fat ZERO when it comes to reality. Again. THIS AIN'T STAR TREK.
Assuming iron, so M = 55.845, Vaporization point: 3134K, Melting point: 1811 K, Heat of fusion: 13.81 KJ/mol, Heat of vaporization: 340 KJ/mol, Specific heat capacity: 25.10 J/mol/K
.5 cm / 3740 cm/s = 134 us
v(rms) = (3RT/M)^.5
v(rms) = 37.4 m/s
Assuming you want the laser focused over 4 cm for a 3 cm object:
t = x/v =
For a 3 cm sphere:
V = 4/3*pi*r^3 = 113 cm^3
m = Vd = 113 cm^3 * 7.874 g/cm^3 = 890 g
890 g / 55.845 g/mol = 16 mol
16 mol * (25.10 J/mol/K * 3134 K + 13810 J/mol + 340000 J/mol) = 7 MJ
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Though that assumes extremelly rapid heat transfer across the ball; I guess with such short pulses it might as well largely melt at most / with some plasma forming on the side of impact? With longer it becomes harder to track, also because it gets what is essentially a powerful and not fully predictable delta-v.
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As explained in the first couple slides, blowing up spent vehicles in low orbit forces them to re-entry almost total within one week.
The problem is the debris fields caused by accidental collisions and large clouds of debris caused by high orbit destruction. These stay up there for a very long time.
But the article is far too heavily focused on prevention by building in de-orbit mechanisms, with too little attention paid to recovery of objects already in orbit.
Clearly we will not be able to gather every nut
What problem? (Score:3, Funny)
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I'm thinking create a couple of small singularities in low earth orbit and let them vacuum up the space debris. Let gravity do the work. What could possibly go wrong?
The perfect solution has already been worked out (Score:4, Interesting)
This is the solution:
http://en.wikipedia.org/wiki/Salvage_1 [wikipedia.org]
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Heh. I sort of remember this show. There are no torrents for it on TPB so I wonder if there is a way I can go back and watch these again. I remember liking the show when I was a kid... I also enjoyed Space 1999. I was able to download those though.
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This is the solution:
http://en.wikipedia.org/wiki/Salvage_1 [wikipedia.org]
Two words...Fly paper.
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This "fly paper" is then mounted on a cermet [wikipedia.org] frame that has bolting lugs to attach other frames to increase the square foot area.
All on a sesame seed bun.
Any further discussion, Show Me The Money!
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The Great Lower-Orbit Garbage Patch (Score:1, Interesting)
Obligatory space elevator post... (Score:1, Redundant)
Economic solution: (Score:2)
Turn the ISS into a gift shop and sell all the bits of junk as souvenirs on eBay, Craigslist, and the Shopping Network. The shipping cost will be a bitch but people will buy it anyway just to be the first on their block with *that* on their mantle (or in their front yard).
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Is there anything the free market can't solve?
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I'd say the shipping costs would be quite low, actually. Fast delivery times too. You could place your order, grab a baseball glove, head out to the back yard, and receive your package 5 minutes later.
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Well, sure, if you opt for the air freight shipping....
Lasers... (Score:5, Interesting)
This guy [ted.com] built a laser which tracks mosquitoes in a room and zaps them. Surely the technology can be adapted...
Re:Lasers... (Score:5, Interesting)
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> ...a wonderful proof-of-concept demonstrator...
What concept do you think it would prove? "Hitting stuff with a laser" is not very hard and has been demonstrated many times, even in space.
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That's a very different proof than "hitting something with a laser in space."
Re:Lasers... (Score:4, Informative)
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Actually it's the same problem.
Satellite controllers use the radar-tracking derived ephemeris data from NORAD. It's a simple matter of changing a search parameter in the data request to get the debris trajectories.
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Not to point out the obvious, but killing flies and destroying space junk are two very different things.
The insect laser only needs to wound the insect enough that it is no longer a trouble- badly damage the wings, or cause it bodily injury. The insect then tumbles harmlessly to the ground.
The debris laser needs to do one of two things- either impart enough thermal energy to the junk so that it's trajectory is changed, causing it to de-orbit, or to disintegrate it into such tiny pieces that it no longer pos
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Having something that can do all that with enough power to actually be useful, able to do it over and over again without running out of consumables, and do that on a sane budget-that's tricky.
Agreed. This is precisely what makes it an interesting and worthwhile engineering project to work on.
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Heat dispersal is a real big issue in space, so far radiating it away is the only solution and that's not terribly easy or efficient.
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That idea will work perfectly as soon as you figure out how we're going to be able to hear space debris buzz.
Or did you think that guy's laser detected mosquitoes with magic?
Out of dimension? (Score:3, Interesting)
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Re:Out of dimension? (Score:5, Informative)
You need to get through all the orbits of uncontrolled junk, which takes a lot of calculation and you can only move so fast.
You have to be able to get out of the way of new junk that's moving so fast you can't accelerate quickly enough to wait and see if it might miss you.
Calculation of junk trajectory is only so precise, so you have to leave a 'safety buffer' of sorts.
There's more junk up there than we have cataloged. There will always be new junk, and collisions alter orbits of existing junk such that our known trajectories become inaccurate and we have to relocate and recalculate all the time.
So finding a safe zone which requires the least fuel usage to stay alive is becoming more challenging.
Tiny fragments that wouldn't harm anyone if you threw it at them are deadly, equipment-wrecking projectiles at high velocity. Think about a small piece of metal, like a penny. Not a problem if you drop it on your foot. Not going to destroy a vehicle if you drop if off a towering skyscraper, even. But, in space where there's no[t enough] atmosphere to slow it down or burn it up, it can theoretically approach any speed... and a 1,000 MPH penny is a fearsome entity to a fragile laboratory measurement device. We might not even be able to track that very accurately, but if you guess wrong... you transfer that momentum into multiple new shards of former expensive equipment!
So getting things into space is really getting more complicated and keeping things alive up there takes a lot more calculation and fuel as the probability of stray objects increases. Does that cut down on the exaggeration factor?
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One hit can ruin a billion-dollar project, and create a multi-billion dollar investigation and recovery effort.
The shit needs to be cleaned up.
Re:Out of dimension? (Score:5, Informative)
Consider that each object (in low Earth orbit) is in a separate orbit. Each pair of orbits crosses twice on opposite sides of the Earth. The eccentricity of each orbit causes the object to traverse a range of altitudes, defining the subset of all the LEO objects that are possible collision risks at any given time. The risk for two particular objects colliding is low, but each object has many other opportunities as it crosses thousands of other orbital tracks each time it circles the Earth. Then integrate over all the objects. The probability is a nested summation - integrated over time.
For example, assume there are about one hundred spacecraft (active and defunct) occupying a particular semimajor axis "zone". Each satellite orbits once every 90 minutes, ie, 16 orbits/day. Each satellite crosses the orbit of another about 200 times in that 90 minutes. Usually the other spacecraft is somewhere else entirely, but there are a lot of opportunities.
Establish a "comfort radius" - say, one kilometer. If Le Petit Prince is sitting on a satellite, he will get very nervous if another spacecraft zooms through this keyhole at 10 km/s. A typical low Earth orbit is about 42,000 of these comfort units long. So the odds (ignoring altitude for the moment) of finding a spacecraft within the same part of the orbit - during each passage - is 1/42,000. Multiply by the 200 opportunities makes this 1/210 (0.5%) per orbit or about 7.5%/day/spacecraft. There are 100 spacecraft in this zone, so that amounts to about 4 close encounters per day (divide in half since it takes two to tango) in which some spacecraft passes directly above or below another by a few kilometers.
Accounting for altitude requires a bit more physics (inverse square law and all that), but basically amounts to a similar argument of dividing the altitude range traversed by each satellite into comfort zones. The odds of passing through the keyhole drop, but not dramatically - and the orbit crossings keep piling up about a hundred thousand per day per altitude range. With each close encounter, the odds of an impact are basically very simple. What is the volume of a typical spacecraft divided by the 1 km^3 volume? (The second spacecraft either will or won't be occupying the same volume at the moment of closest approach.) Satellites can be surprisingly large - Hubble is about the size of a schoolbus - but figure a Volkswagen van or at least a Beetle.
Bear in mind that this is just one particular altitude range, the same thing is happening at different altitudes. Some spacecraft are in highly elliptical orbits and cross through several such zones. In short, what seems to be a three dimensional problem is really one dimensional. After the spacecraft collision a couple of years ago some of us were scribbling on a blackboard. A physical model would be needed to get the precise answers, but a ball park figure is that we can expect the apparently astronomically rare event of two LEO spacecraft colliding to happen about once per decade (in the absence of active station keeping). Then account for all the debris, not just complete spacecraft.
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As of now there is a serious debate as to whether or not Kessler Syndrome threshold density has already been reached in some orbital bands. Even if there is a certain level of exaggeration, that's a very preferred side of the "error" (wouldn't be the first and only present example of actually underestimating the consequences though)
The real problem... (Score:5, Funny)
The main obstacles being shark deployment and survivability.
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The main obstacles being shark deployment and survivability.
Yeah, shark fin soup is mighty tasty.
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Maybe it's not such a big problem? [wikia.com]
Also, allow me to use this opportunity and point out how "frozen bags of astronaut urine" can bring a whole new meaning to "get pissed on"...
Asteroids the game has suddenly become real (Score:1, Interesting)
I think this applies... (Score:5, Funny)
Hi there! Your post advocates a
( ) technical ( ) legislative ( ) market-based ( ) vigilante
approach to fighting space junk. Your idea will not work. Here is why it won't work. (One or more of the following may apply to your particular idea, and it may have other flaws which used to vary from state to state before a bad federal law was passed.)
( ) Junkers can easily use it to create more space junk
( ) Space stations and other legitimate space uses would be affected
( ) No one will be able to find the guy or collect the money
( ) It is defenseless against brute force space dumps
( ) It will stop space junk for two weeks and then we'll be stuck with it
( ) Users of space will not put up with it
( ) NASA will not put up with it
( ) The space police will not put up with it
( ) Requires too much cooperation from space junkers
( ) Requires immediate total cooperation from everybody at once
( ) Many space users cannot afford to lose business or alienate potential employers
( ) Space junkers don't care about other junk in their junk
( ) Anyone could anonymously destroy anyone else's career or business
Specifically, your plan fails to account for
( ) Laws expressly prohibiting it
( ) Lack of centrally controlling authority for space
( ) Launches in foreign countries
( ) Difficulty of searching for tiny junk in all of space
( ) Asshats
( ) Jurisdictional problems
( ) Unpopularity of weird new taxes
( ) Public reluctance to accept weird new forms of money
( ) Huge existing investment in space
( ) Armies of worm riddled broadband-connected Windows boxes
( ) Eternal arms race involved in all space junk collection policies
( ) Extreme profitability of space junk
( ) Joe jobs and/or identity theft
( ) Technically illiterate politicians
( ) Extreme stupidity on the part of people who do business with space junkers
( ) Dishonesty on the part of space junkers themselves
( ) Fuel costs that are unaffected by space junk
( ) Outlook
and the following philosophical objections may also apply:
( ) Ideas similar to yours are easy to come up with, yet none have ever
been shown practical
( ) Any scheme based on opt-out is unacceptable
( ) We should be able to talk about space Viagra without being censored
( ) Countermeasures should not involve missles
( ) Countermeasures should not involve more junk
( ) Countermeasures must work if phased in gradually
( ) Sending things to space should be free
( ) Why should we have to trust you and your space garbage company?
( ) Incompatiblity with space licenses
( ) Feel-good measures do nothing to solve the problem
( ) I don't want the government cleaning up space
( ) Killing them that way is not slow and painful enough
Furthermore, this is what I think about you:
( ) Sorry dude, but I don't think it would work.
( ) This is a stupid idea, and you're a stupid person for suggesting it.
( ) Nice try, assh0le! I'm going to find out where you live and burn your
house down!
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There, fixed that for you. I'm certain that bad Powerpoint presentations will still be creating tons of space debris after we're all dead.
Tethers and such are not a way to clean up. (Score:2)
They are just ways to keep the mess from getting worse very fast. They do nothing about the existing junk or the results of many probable accidents.
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The rate of orbital decay should eventually (years, decades, centuries) take care of everything in low earth orbit. So if we can stop putting stuff up there which doesn't decay well, eventually we should have less stuff overall. Maybe.
The various space junk are like people and teeth. If you ignore them for long enough, they'll eventually go away.
Orbital Junk (Score:2, Funny)
Nuke it from orbit. It's the only way to be sure.
wait...
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I guess that would be "just detonate the nukes already in orbit" in that particular case.
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Max Headroom has the solution (Score:2)
20 minutes into the future, Mardi Gras will be replaced by "Sky Fall", a week-long festival where this year's space junk is intentionally grounded by remote control to crash into the sea or burn up in the atmosphere.
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Incinerator (Score:1)
Why don't we toss junk into the sun?
Re:Incinerator (Score:5, Funny)
The same reason you don't carry your car to work to save gas money.
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Sure. You do the tossing.
Lasers are quite feasible for this... (Score:2)
Magnets (Score:2)
There must be some kind of application for magnetics out there.
Principal Skinner... (Score:2)
...is that you?!
Put ointment on it (Score:2)
Simple is Better (Score:3, Interesting)
A simple solution might be to send up a sounding rocket to the altitude where a typical debris cloud is and just release a cloud of nitrogen gas. the cloud will fall soon into the atmosphere, the sounding rocket will too. the debris field will have a short time in a very low density gas cloud, and drop in it's orbit. Normal decay will then reduce the overall problem.
Presumably, the AF knows where the debris is. Look for any clusters. Publish where and when it is going to be taken out. Unless someone objects, with a why, then do it. Probably find out who owns a lot of the back satellites that way.
Begin to get rid of the litter. We won't finish until after we start. Right now, there is no cleanup.
Maybe a first test run, then, when we can predict the outcome, a regular program of removal.
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> ...typical debris cloud...
There are no debris clouds. Each individual bit of scrap is in its own orbit.
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Presumably, the AF knows where the debris is.
Yeah they do.
Look at all the dots [wikipedia.org]
Obligatory Star Wars Quote (Score:2)
Switch all power to *front* deflector screens.
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Switch all power to *front* deflector screens. Switch all power to *front* deflector screens.
Are sure you don't mean "forward"?
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http://www.youtube.com/watch?v=6v5VahaEL7s#t=1m18s [youtube.com]
"We're passing through their magnetic field."
"Hold tight."
"Switch your deflectors on double-front."
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Simpler solutions (Score:1)
Blowing the debris up, in various ways, just makes the problem worse by making more pieces instead of fewer.
Dropping them to the Earth means a chance of dropping them on someone/thing. They should design in a safe burn-up plan instead of letting it fall wherever.
The best solution is to not generate debris in the first place. Too much of this crap is just some country sending up a "look at me" advertisement, like China's blowing up satellites.
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Depends. Blowing up large objects that are in low orbit breaks them into many tiny pieces that re-enter quickly instead of remaining in orbit for decades.
Most of the stuff is already such that it would not survive re-entry.
The answer is simple: Funding. (Score:3, Informative)
We don't need new strategies for getting objects down from space. We know how to get them down. When a satellite has outlived its usefulness, you reserve enough fuel so that it can deorbit itself.
The problem is that satellites are expensive and rare still, so we don't want to give them up. So we keep the missions up there for years past their expected lifetime, with the result that they don't have deorbiting fuel left over when they finally break down enough that they're no good to us anymore.
An example: I work with Landsat 5. It was launched in 1982 with a 5 year mission plan. It's still up there, 28 years later, and still a vital piece of the US remote sensing strategy. The next similar satellite won't be launched until 2012. Although it had a deorbiting plan that would have sunk it into the atmosphere a few years after it was decommissioned, that plan was waived. The current plan is to put it into an orbit that will leave it as space debris for 1000 years before it gets low enough to burn in.
If we had funded the satellite program enough, there would have been several follow-on missions and L5 would not still be essential. We would have been able to deorbit it without complaint if there were others that could have taken its role.
Fund space and you won't have space problems. Don't fund it and it'll become a graveyard. Simple as that.
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At least non-fuel-dependant methods wouldn't be abused so much in current climate... and overall might be cheaper when it comes to launch mass (assuming the same mission duration and fairly certain , fairly quick deorbiting, even if it wouldn't be precise at all with, say, a drag sail)
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Make a Ring (Score:1)
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Seriously, Those astronauts aren't really doing anything up there anymore. Let them go up and start arranging the junk in the shape of a ring
Seriously, PHD garbage men.
How do gat a PHD off your porch?
Pay for the pizza they deliver.
Why all this talk about shooting it down? (Score:2)
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Every bit of trash is in a different orbit. It takes expensive fuel to change orbits. Collecting it all in one place would cost more than simply launching the same amount of stuff from the surface.
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Well sir, there's nothing on earth
Like a genuine,
Bona fide,
Electrified
Space-age
Elevator!
Ned Flanders: Elevator!
Lyle Lanley: What's it called?
Patty+Selma: Elevator!
Lyle Lanley: That's right! Elevator!
[crowd chants `Elevator' softly and rhythmically]
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We've already spent billions getting it up there, why not recycle it? Create a recycling station in orbit.
Sorry, my prior designs originate in the late 70's. Therefore I hold a prior copyright on intellectual property.
Get a big gun (Score:2)
Target Practice?
recycle recycle recycle... (Score:2)
well, ok. some of it http://idle.slashdot.org/story/10/08/31/1713210/Whisky-Made-From-Diabetics-Urine [slashdot.org] isn't completely recyclable but...
Gentlemen, Gentlemen. (Score:2)
We've been over this many times before, and we already know what the solution [imdb.com] will be, when we are ready to commit to it.
space sharks (Score:2, Funny)
Totally Lunatic Idea (Score:2, Interesting)
Re:Hmm (Score:4, Informative)
Why shouldn't it be hard? Large changes in velocity require large amounts of fuel. Doesn't matter if you are "speeding up" or "slowing down". That's why so many of these ideas involve working out a way for satellites to increase their drag after a time.
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Depending on what kind of deorbit profile you develop, ....
Always with the de-orbit. Reduce, reuse, recycle, oh, and recover. All satellites are insured with really big recovery fees.
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Statistics... (Score:4, Informative)
...that is not how they work.
There are no 669,725 people that are in any more danger than anyone else. There isn't a 1/10,000 chance that it will hit each person, there is a 1/10,000 chance that it will hit any person. In other words, for every ten-thousand pieces of space junk that fall, you might get a single casualty.
If you think these are particularly bad odds, then I have some bad news about your car...
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...or produce more of the debris. An why even a mention of "pilot-able", what for?