NASA's Top 10 Space Junk Missions

Ant writes "NASA has identified the top ten space junk missions and said over 19,000 pieces of space junk are known to exist..." That's nothing: You should see my living room.

Comments

Radioactive coolant

[Tisha_AH]

One of the biggest sources of space junk are the gobs of solidified radioactive coolant from old Soviet satellites.

Re:Radioactive coolant

[Tisha_AH]

A great article on the space junk problem can be found at;

http://www.satellitetoday.com/commercial/manufacturers/Space-Debris-Small-But-Growing-Problem_21599.html

They discuss the radioactive coolant losses from discarded satellites that were boosted into "graveyard orbits" and how the cooling systems have sprung leaks, leaving behind solidified chunks of radioactive sodium, potassium and lead.

Re:Radioactive coolant

[Anonymous Coward]

Well, according to the list, one of the biggest is the intentional destruction of a satellite in a high, stable orbit with an anti-satellite weapon by the Chinese.

It's more than double the space junk of the next three worst COMBINED. And is the only intentional one on the list.

Re:Radioactive coolant

[blair1q]

"radioactive" is a relative term.

Outside the atmosphere space is full of particles (cosmic rays) that can kill you faster than playing handball with radioactive sodium.

Re:Radioactive coolant

[mhajicek]

Do that a few more times and they have an orbital area denial system.

Space sized bin bag

[notaspunkymonkey]

Can't we just remove the larges pieces? Surely we could "drag" some of this larger stuff back down to earth?

Re:Space sized bin bag

[srothroc]

What nation wants to spend money to send people up into space to clean up after what's essentially other people's garbage? There's no immediate gain, so nobody's going to do it.

Re:Space sized bin bag

[notaspunkymonkey]

True, The nations who are leaving stuff in space should be responsible for trying to remove as much of their mess as possible. Leaving the Envisat Earth observation satellite floating around should not be permitted (I know.. who polices space etc)

Re:Space sized bin bag

[Tisha_AH]

Much of the space debris is in very small pieces like paint chips, pieces of thermal blankets, screws/nuts/bolts, etc..

The volume of near space that is "polluted" is vast. It is a constantly evolving three dimensional environment with debris moving at all sorts of crazy trajectories that change frequently depending upon the solar wind, geomagnetic field and the swelling and contraction of our tenuous upper atmosphere.

It would be like searching the beach in Fiji, looking for a particular 1957 nickel. The efforts to chase down each individual piece of trash is much greater than the risks of that particular piece.

We need to;
1. Stop spewing little parts, disgards and trash into space.
2. Do a better job of tracking what is up there.
3. Harden satellites to be able to survive the impact from a very small object.
4. Come up with a clean way to dispose of old space hardware other than abandonment in "graveyard orbits".
 

Re:Space sized bin bag

[jonbryce]

Maybe some international body could charge a property tax on birds up there and use it to fund regular garbage collections, a bit like local councils down on earth.

Re:Space sized bin bag

[GaryOlson]

Sure. The same method as used to clean up the largest portion of the oil spill in the Gulf....don't allow anyone to take pictures.

Re:Space sized bin bag

[rickb928]

"It would be like searching the beach in Fiji, looking for a particular 1957 nickel."

By that analogy, how do fishermen around Fiji actually catch fish? Chase one around with a net until they get the advantage? No, they cast the net, catch what is there, and throw back the rest.

Who sent a satellite to capture comet dust? Oh yeah, us. "Stardust'. Aerogel as a capture mechanism for comet material.

Why not try sending some aerogel into LEO and use a similar method? Send it through debris fields, verify useful capture, and then throw it into Earth to either burn up or land somewhere 'safe'. Pick it up and throw it in a landfill, or send it off to be autopsied.

I know there are challenges - a maneuverable spacecraft, fuel, coordinating the orbits, where to land the debris, who gets it back. But this seems obvious to me. Aerogel is uniquely suited to this.

Alternatively, there are other ways to catch debris if you don;t much care what shape it is in when you catch it. A few layers of metal and some intervening goo, for instance. But aerogel is so light that it's cheaper to send up, it captured comet debris adequately, so it would probably be great to catch a lot of small stuff. Larger items may need a bigger or better 'net'.

It's about the money, and what to do with the more interesting pieces of junk. Russia may want their satellite stuff back.

And of course, if we do this, we just encourage China to keep on testing space weapons. Is this good?

Re:Space sized bin bag

[slick7]

What nation wants to spend money to send people up into space to clean up after what's essentially other people's garbage? There's no immediate gain, so nobody's going to do it.

One man's junk is another man's treasure. I have ideas about this very idea going all the way back to the late 70's. Why haven't I done anything about it, you may ask? Simple, not finding a backer with the funding that also has the forethought to move forward in a time frame that made space collection unrealistic and unnecessary. And now, the necessity is realistic, but now more expensive.

Re:Space sized bin bag

[slick7]

Maybe some international body could charge a property tax on birds up there and use it to fund regular garbage collections, a bit like local councils down on earth.

Why? The insurance recovery fee would do more than make up the difference. A $100 million satellite that goes bad because of a $1500 circuit board can be re-activated if somebody could get to the satellite either physically or by remote tele-presence.
The ISS can be setup as a base of operations, but a commercial space station would be better.

Re:Space sized bin bag

[Martin Blank]

Setting up a net isn't that easy. Aside from the 19,000 "large" items (those over about 10cm), there are tens of millions of smaller items like washers and paint flecks. Let's say there are 50 million such objects between altitudes of 150 miles and 300 miles. That space totals up to 11.7 billion cubic miles for an average about 235 cubic miles per piece of debris. There are, of course, higher densities in some spots, but not enough to make something like this economical.

Additionally, aerogel is some fragile stuff. I know it is, because I have some at home. It came from a polite request to purchase some small, random piece from an aerogel manufacturer about ten years ago, and the person who replied was kind enough to simply put a piece of shop scrap in a plastic box and send it to me (complete with MSDS). Within ten minutes of opening it and despite what I thought was careful handling, I had broken the piece in two, and in the intervening years, it has broken further into about six major pieces and a dozen minor bits. It may be good for capturing micrometeors, but it would shatter if it were hit by a bolt, adding to the debris problem.

As for who gets back the space debris and whatever else is deorbited, the answer should be "nobody." Send it to break up over the Pacific. If a country wants something back badly enough, they can design the important parts to survive re-entry and bring it back on their own, or provide funding for a dedicated retrieval mission.

Re:Space sized bin bag

[SETIGuy]

Alternatively, there are other ways to catch debris if you don;t much care what shape it is in when you catch it. A few layers of metal and some intervening goo, for instance. But aerogel is so light that it's cheaper to send up, it captured comet debris adequately, so it would probably be great to catch a lot of small stuff. Larger items may need a bigger or better 'net'.

There's a big difference between catching an interplanetary dust particle and catching a tiny screw or even a paint chip. A paint chip is going to be a thousand times heavier. A screw will be a million times heavier. So you're talking aerogel that is meters thick. Anything small enough to capture with aerogel is going to be essentially worthless, so there's no money to be made sweeping space of small objects

There must be no debris resulting from the collision, including aerogel. Since you're not going to be able to categorize most particles before impact, you need to design for the largest unidentified piece you might meet. In the end you're talking about hundreds of millions to get rid of a tiny fraction of the problem. You're better off spending that money on prevention.

Re:Space sized bin bag

[LanMan04]

http://en.wikipedia.org/wiki/Planetes

The story of Planetes follows the crew of the DS-12 "Toy Box" of the Space Debris Section, a unit of Technora Corporation. Debris Section's purpose is to prevent the damage or destruction of satellites, space stations and spacecraft from collision with debris in Earth's and the Moon's orbits. They use a number of methods to dispose of the debris (mainly by burning it via atmospheric reentry or through salvage), accomplished through the use of EVA suits.

The episodes sometimes revolve around debris collection itself, but more often the concept of collecting "trash" in space is merely a storytelling method for building character development. The members of the Debris Section are looked down upon as the lowest members of the company and they must work hard to prove their worth to others and accomplish their dreams.

Re:Space sized bin bag

[Demolition]

Does anybody remember "Salvage 1" starring Andy Griffith? The premise involved a junkyard owner who builds a rocket so that he can salvage abandoned moon landing equipment (e.g. lunar landers, rovers, cameras, etc.) to sell for profit upon returning to Earth.

It ran for 1.5 seasons back in 1979-80. It was one of the many things that sparked my interest in space exploration when I was a kid.

Re:Space sized bin bag

[BraksDad]

Sounds a bit like Red Dwarf.

Cosmos 2421

[feedayeen]

Cause of Breakup : Unknown. What the hell happened to you Cosmos?

Re:Cosmos 2421

[SJ2000]

http://russianforces.org/blog/2006/07/problems_with_cosmos2421.shtml
http://russianforces.org/blog/2008/03/cosmos2421_completed_its_missi.shtml

Time to develop..

[RobiOne]

.. a tractor beam, and depending on how wide the beam is, in 24 hrs, an entire strip across the sky could be debris free.

Could also be a national attraction watching things sparkle and burn up as it's doing re-entry.

Re:Time to develop..

[Flea of Pain]

Most of this stuff is metallic right? Possibly even magnetic? Methinks we need a Wile E. Coyote style ACME space-junk removing magnet! As an added benefit, it may trap fast moving birds in its steady stream of space debris!

Re:Time to develop..

[Anonymous Coward]

The magnet would do pretty much nothing whatsoever.

A more realistic proposal would be a satellite with a large laser to try and 'nudge' stuff into unstable orbits, or burn it up completely.

This also has the side effect of being WAY cooler.

Re:Time to develop..

[pitchpipe]

Methinks we need a Wile E. Coyote style ACME space-junk removing magnet!

So when the inevitable big space junk collision happens with the ship will it spring back entertainingly like an accordion?

Re:Time to develop..

[qwijibo]

Vaporizing stuff on orbit with a high powered laser sounds like a cool idea, but you're going to end up putting someone's eye out 4 light years away. Sure, lets find out if there are aliens by trying to blind their kids. =)

Re:Time to develop..

[Lumpy]

A small black hole in orbit would do just fine. we have a better chance at making that before a "tractor beam"

Re:Time to develop..

[Lumpy]

Nope and nope.

Most is aluminum and titanuim. Nobody has launched cast iron rockets cince the 30's.

Re:Time to develop..

[RobiOne]

..magnetic field there would have to be enormous, which is not easy to do. Using the one that comes with the planet, could be touchy, as side effects could be unexpectedly bad.

Inducing a charge to the particles to have them be more attractive to an oppositely charged collector system perhaps. What kind of storm can one engineer that high up?

Out military does have high power lasers now, that can track fast moving small objects, and vaporize them. Lots of target practice.

Problem remains, space is full of dust and particles, so shielding to absorb or deflect those bits is the method used in Sci-Fi thought experiments on the subject.

Re:Time to develop..

[mcgrew]

Yeah, well while you're developing presently impossible Star Trek gadgets like a tractor beam, why not just develop a matter transporter and beam the shit down, Scotty?

Re:Time to develop..

[jridley]

Not really. A black hole isn't a magic vacuum cleaner, it's just a gravitational mass. It's not going to suck up anything that isn't in an intersecting orbit anyway. And we would have to get the mass to make it somewhere, meaning we'd have to boost up enough mass to make it, which is hellaciously expensive. If you try to make one that only weighs a few hundred kilograms, it's going to be even less effective than the equivalent in conventional matter, since it would be a point, even its event horizon would be microscopic, so even if something collided with it, it would just punch a hole through the other object as it passed through, it wouldn't even be able to swallow a paint chip.

In order to make one with even a golf-ball sized event horizon you'd probably have to boost up more material than we've ever put into orbit in the past.

Re:Time to develop..

[angelwolf71885]

Methinks we need a Wile E. Coyote style ACME space-junk removing magnet!

ummm i dont think that would be the best method because ACME products always ended badly for him

Re:Time to develop..

[nospam007]

"Vaporizing stuff on orbit with a high powered laser sounds like a cool idea, "

The object will have a different form afterwards with not a single gram removed.

Re:Time to develop..

[$RANDOMLUSER]

Methinks we need a Wile E. Coyote style ACME space-junk removing magnet!

So when the inevitable big space junk collision happens with the ship will it spring back entertainingly like an accordion?

Think of the "GULP .... AWWWW CRAP!!!" look you could give the camera just before you start to plummet when you step off in LEO.

Re:Time to develop..

[slick7]

.. a tractor beam, and depending on how wide the beam is, in 24 hrs, an entire strip across the sky could be debris free.

Could also be a national attraction watching things sparkle and burn up as it's doing re-entry.

Come back from the 23rd century, Buck Rogers, in realistic terms, a high tech flypaper would be simpler and cost effective.

Re:Time to develop..

[Anonymous Coward]

Look up sublimation, sir, and you will understand why it will provide momentum to the mass.

Re:Time to develop..

[camperdave]

The object will have a different form afterwards with not a single gram removed.

True, but the vapour will be affected by the tenuous atmosphere a lot more. Plus it will do less damage if it does hit a ship. Consider the difference in damage caused by an ice cube and the equivalent mass of mist.

Re:Time to develop..

[Anonymous Coward]

Won't someone think of the children!?!?

Re:Time to develop..

[Anonymous Coward]

To make one with the event horizon the size of a golfball you need more mass then the entire earth. If you can do that getting it into orbit should be the least of your problems.

Is this really a problem?

[jgtg32a]

19,000 is a lot but this is space we're talking about, it seems like it would be rather easy to avoid. We're no where near the threat of Kessler syndrome.
 
I'm not saying we should just go around dumping stuff in random orbits

Re:Is this really a problem?

[gstoddart]

19,000 is a lot but this is space we're talking about, it seems like it would be rather easy to avoid.

Well, the damage from any of these objects is potentially catastrophic. It's not like getting a flat tire ... the relative speeds here are enough to cause major damage. The pieces also look like they're fairly well spread out in orbit.

From the linked article, that Chinese satellite that got shot down has created some 2841 pieces -- imagine something the size of a pea striking your orbiter at, what, 10000 mph? That's a lot of kinetic energy.

Re:Is this really a problem?

[Lumpy]

From the linked article, that Chinese satellite that got shot down has created sometrackable 2841 pieces

2841 trackable pieces = 80,000 actual pieces.

Re:Is this really a problem?

[mea37]

If it seems easy to avoid debris, then I suggest you think through the problem again.

First, in orbit you can't move freely. Most of your movement is governed by gravity. Every time you want to deviate from that path, you must spend fuel. You only have so much fuel, you must reserve enough to get home, and you must ensure at the end of each burn that you're still in orbit. You can't just carry more fuel, because fuel takes up launch weight.

The debris is, of course, also moving in an orbit governed by gravity; but it's not following a mission plan. When you just don't care, a lot of different orbits can intersect the same point at the same time with very different velocities.

And, you aren't just "passing through" the debris field. You have to avoid debris for the duration of your time in orbit. If you could project the orbits of all the debris for the duration of your mission, you'd still have to account for a lot of variables (including launch and landing windows) to pick out an orbit suitable for your mission that will be debris-free.

Even for relatively short missions, you can't do that perfectly; and then there are long missions (like satelites and space stations) that are essentially sitting ducks. So to an extent you leave it up to chance; and you think "well, 19,000 pieces of debris in all of the orbital space doesn't sound so bad", but with every minute you spend in orbit the odds that you eventually have an incident increase mercilessly.

If you do notice that you're in the path of a piece of debris, can you dodge it? Depends what you're driving, but I'm pretty sure it's been done. Now, what if you don't see it coming (e.g. because it isn't a piece of debris we're tracking)?

Yes, it is really a problem.

Re:Is this really a problem?

[twiddlingbits]

Approx. 8km/sec is the speed to keep something in LEO. It varies with the eccentricity of the orbit and the mass in relation to the body it is orbiting. 8km/sec is about .6mph/sec. With 3600 secs in 1 hr it's about 2100 mph. Objects in LEO have one hell of a lot of kinetic energy, a 1/10 kg object at 8km/sec would impart 3.2MJ of energy.which is about equal to about 1.5 sticks of dynamite energy displaced onto a stationary object. That much energy will tear up anything not armored against it and even then you need some seriously thick armor. Since weight is the enemy of spacecraft there is very little of that weight devoted to protection from impact. Even small objects like a nut or bolt will cause serious impact as It's not the mass it's the velocity that ramps up the impact. Don't forget that spacecraft are also moving in LEO so the velocity would double sending energy up by 4X. . In simpler terms if you put your McDs' quarter pounder into orbit you got a hell of a weapon of you can smash it into something.

Re:Is this really a problem?

[shentino]

Which is another thing.

What good is it going to do for one country to take up the space mop if other countries keep using it as a dump?

Re:Is this really a problem?

[sjames]

Not to mention that is anything collides with any of those 19000 pieces, it'll change orbit and you get to recompute everything.

Re:Is this really a problem?

[slick7]

Which is another thing.

What good is it going to do for one country to take up the space mop if other countries keep using it as a dump?

Easy, kick it back down stairs where it came from. Keep doing it until they (being those that are called them) get the idea to assist in paying for the cleanup. Just like dog owners picking up after their dogs.

Summary a bit vague...

[Robotron23]

That's nothing: You should see my living room.

So...you're either a heroin addict, a messy slob, a collector of Chinese model boats, really do have pieces of souvenir space junk, or have a hobby for acquiring pickled male genit...okay:

Tell us Ant, which 'junk' is most true for your living room?

Re:Summary a bit vague...

[Chris Burke]

Well from context I'm assuming they're talking about space junk... But that still doesn't answer the question of what kind of junk. Space heroin? Space Chinese boats? Space genitals?

Also from context, I'm assuming they're implying that entering their apartment will result in one being torn apart by said space junk much like a satellite caught in the path of orbiting debris.

Which makes the possibility that they meant genitals even more horrifying.

Re:Summary a bit vague...

[antdude]

You should ask CmdrTaco, I didn't put my living room but he did in my story. In fact, I don't even have a living room where I live. However, my room is messy though! :)

Re:Summary a bit vague...

[Robotron23]

Yeah I realized that some time after I hastily posted just prior to resuming work - I think Rob was trying to be funny (?). No way would he get away with a typical bachelor's household in his status.

Furthermore...being a millionaire you'd assume he just hired a maid in twice weekly to clean up his lounge excesses. Hence me thinking his summary as more a bad joke than a comment on his home as it is.

Chris made a good point over the vagaries of the Slashdot summary; I enjoyed the thought of Taco's home being ripped apart by a piece of space junk falling onto it... ...while CmdrTaco is out of the home of course, so we could read what would be the best Slashdot post since his wedding proposal wayyy back. :D

Re:Summary a bit vague...

[Anonymous Coward]

And now I'm imagining the combination of Space Oddity and Labyrinth: new music video, starring... David Bowie's Crotch!

Thanks a whole lot, slashdot.

I'll warn the aliens

[curado]

I'll let my alien friends know so they can keep an eye out for it. Wouldn't want another Roswell on our hands when somebody sucks astronaut crap into their plasma engines.

Re:I'll warn the aliens

[MoeDumb]

Get off it, you have no alien friends. My alien friends say so.

Re:I'll warn the aliens

[slick7]

Get off it, you have no alien friends. My alien friends say so.

Anyone claiming to have "alien" friends, probably doesn't have any friends.

Questions questions questions

[teebob21]

For the sake of discussion, let's assume this report showed a problem orders of magnitude worse, and we were on the verge of Kessler syndrome conditions. What technologies exist today to combat the problem? (Yes, I know, no government today would unilaterally scrub space without a quid pro quo...)

If there are 19,000 trackable chunks of debris, how many untrackable (and just as deadly) small particles are there? I know that particle densities are minute. If we launched an array of satellites with Aerogel paneling, is it reasonable to expect a significant improvement in "air" quality up there?

What about that heat-ray device recently pulled our of Afghanistan? Can we launch one of those to spray microwaves tangentially to the Earth's surface? Would the heat applied to a paint-chip sized debris particle be enough to change the orbit? It doesn't take too much delta-v to alter the eccentricity of a paint fleck enough to burn up in orbit, does it?

(Less coffee, more sleep next time, methinks)

Re:Questions questions questions

[MozeeToby]

A ground based laser broom with adaptive optics is probably the only remotely cost effective way of mitigating the problem. From the ground you can't easily reduce an objects velocity but you can push it into a more elliptical orbit, if you can get it elliptical enough you put the perigee inside Earth's atmosphere and let that do the rest. It's the only way I've heard about that doesn't involve a ludicrous number of launches but at the same time will work only for relatively small pieces of debris in low orbit. Luckily, that's where the majority of the problem lies so it might be effective enough until we can deal with the rest.

Re:Questions questions questions

[Capt.DrumkenBum]

You need a cooler method.
This http://www.imdb.com/title/tt0078681/ is a much cooler method.

Re:Questions questions questions

[veganboyjosh]

in other words...

"Nuke them from Earth. It's the only way to be sure."

Re:Questions questions questions

[PingPongBoy]

if you can get it elliptical enough you put the perigee inside Earth's atmosphere

Lovely, if you can have ALL items touching the atmosphere in the same zone, and they all line up in the same path.

However, the orbits will likely just be in every possible plane and have every possible center. As they approach Earth, they get accelerated by the smaller radius, and pretty soon there will be superspeed space junk everywhere coming from all directions.

A very expensive brute force solution: capture each object and then act - take it to the sun, cut it up with lasers, collect it in a single container. Just don't drop it in my back yard.

Re:Questions questions questions

[Confusador]

Here's more information than you wanted, but the International Space Elevator Consortium is working on a position paper on space debris this year. You can find the draft here. They spend a fair bit of space on debris mitigation proposals, and the answer is that there really isn't the tech yet. Their conclusion is that that means it's rather important that we stop making the problem worse.

Re:Questions questions questions

[initialE]

What you are talking about, of course, is an anti-satellite weapon. Do you foresee any problems with any nation possessing this technology and openly showing it works?

Re:Questions questions questions

[Laser Dan]

if you can get it elliptical enough you put the perigee inside Earth's atmosphere

Lovely, if you can have ALL items touching the atmosphere in the same zone, and they all line up in the same path.

However, the orbits will likely just be in every possible plane and have every possible center. As they approach Earth, they get accelerated by the smaller radius, and pretty soon there will be superspeed space junk everywhere coming from all directions.

No, the whole point of getting the pieces to touch the atmosphere is that atmospheric drag slows them down, lowering the orbit even more until they eventually burn up or crash (depending on the size).

Re:Questions questions questions

[teebob21]

You must be new here. http://tech.slashdot.org/story/10/07/19/1917237/China-Shoots-Down-Another-Satellite

recycling

[pha7boy]

If we could monetize recycling in space, we'd clear that area up in quick order. maybe once private space flight and delivery takes off, someone will find a way to gather, break down, and recycle all the (otherwise very expensive) stuff up there.

Re:recycling

[Scatterplot]

Recycled paint chips, radioactive coolant, nuts, bolts, and that bag of tools that the astronaut lost that time *may* not have that much value in space. I wish it did, because if there was money in it then it would get done, but even if you find a giant block of gold up there how are you going to refine it? Not to mention just catch it in the first place- you'd have to match the orbit pretty well otherwise it would be going far too fast to catch. It's not like it's oh look at that rusty space toothbrush floating by, its more like a sharp piece of titanium moving at a billion miles per hour ripping up your satellites.

Re:recycling

[sgrover]

Deposits work for bottles and cans, why not satellites? The homeless can then make some spending cash while cleaning up the area.

Better line

[Anonymous Coward]

That's nothing: You should see my living room.

That's nothing: You should see my Star Trek: Voyager memorabilia collection!

There is a positive side though

[SuperKendall]

Any incoming asteroids will be obliterated by the many impacts with space debris long before they make planetfall, creating an even larger and more protective Space Shield.

We should develop an X-Prize for a space-junk vacuum, with the emphasis being on something that does not "collect" live satellites as well...

Top tens

[Anonymous Coward]

Of the top ten astronaut pick up lines "want to check out my space junk?" was number one.

Kepler

[Anonymous Coward]

Can the Kepler Telecope detect alien space junk or even Alien's Living Room Junk?

Interesting Headline

[BJ_Covert_Action]

What's the eleventh space junk mission? NASA employees are subjected to a briefing of the most recent Congressional budget plans for NASA....

Related Short Story

[rwv]

I recently wrote a short fictional story about an imagined "space tourism" business where commercial vessels fly up into LEO for the purposes of "fishing" for debris satellites that are floating around up there. Link is here

Any chance this may become a reality in 10-20 years?

Short answers, more like guidelines

[starglider29a]

In no order:

• It takes the same delta-v to de-orbit any two masses in the same orbit. Paint chip or Star Destroyer. Thrust requirements follow Newton, not Roddenberry.
• Whatever energy you have to apply to an object must be applied to the object. It's 100km away at 7km per second. Good luck.
• The delta-v to get close enough to where you can apply delta-v (bump a paint chip) adds up. If you could hit it with a beam from 100km away, that would be great, but delivering delta-v at 100km is problematic.
• Almost nothing is magnetic, so forget that. We don't have a tractor beam, and Yarkovsky Effect is insignificant on these tiny pieces. A maser/laser doesn't deliver momentum very well. Heat does nothing.
• Blobs of Aerogel in a counter-directional/retrograde orbit could sweep up the small stuff, but the volume that needs to be swept is like mopping a basketball court with a cotton swab.

Solve the "how do you apply force at a distance" issue and yer halfway there.

Re:Short answers, more like guidelines

[notaspunkymonkey]

I agree with all of the above. I don't understand it but this guy sounds like he knows what he is talking about.

Re:Short answers, more like guidelines

[Shadow Wrought]

It takes the same delta-v to de-orbit any two masses in the same orbit. Paint chip or Star Destroyer. Thrust requirements follow Newton, not Roddenberry.

I am not a physicist, but it seems that inertia would count for something. I could also be misreading it, but it doesn't sound right that the same nudge is needed to de-orbit a paint chip would also de-orbit a Star Destroyer. I would think that an astronaut, matching the orbital speeds, could flick the paint fleck and send it into a terminal plunge. I have a hard time believing a Star Destroyer would notice.

Of course most of my groundings space physics are Lucasian as opposed to Roddenberrian, so I think I'm at an even greater disadvantage :-)

Re:Short answers, more like guidelines

[teebob21]

Parent was correct: same delta-v for differing masses. However, since delta-v is nothing more sophisticated than good ol' acceleration (Force x Mass), you do need more force for a greater mass to reach a given delta-v.

My question was along the lines of inducing acceleration in very low mass particles using the principles seen in a Crookes radiometer. http://en.wikipedia.org/wiki/Crookes_radiometer Possible?

Re:Short answers, more like guidelines

[pz]

You can release a non-trivial amount of chemical energy through non-uniform heating such as from a remote laser trained on one part of an object. If beam-created local heating causes vaporization, the force applied to the object can be larger than from the energy of the beam alone.

Or so I've heard.
 

Re:Short answers, more like guidelines

[starglider29a]

Parent is a degreed Aerospace engineer. You are correct about the delta-V. Google "specific impulse" and realize why it takes a 365 foot rocket to lift a volkswagen. That is... why the propellant to payload ratio is so freaking high! (Technical term)

Regarding the radiometer: The answer is 'yes, but...' You would have to hit the object with enough "photon momentum" to change the velocity, literally, delta the v. The losses of distance, surface area reduce your killer beam to a few photons pretty fast. And it's SURE not worth the cost.

Magnitudes are your enemy here. If you shot a .308 rifle out the "back" of the ISS (retrograde to velocity), the bullet probably wouldn't de-orbit. That's a lot of delta-v! If you shot it straight down (down the radius vector), it would loop around you and come back DOWN at you 1 orbit later and at the same velocity it left!

Re:Short answers, more like guidelines

[starglider29a]

causes vaporization, the force applied to the object can be larger than from the energy of the beam alone.

Only if the vaporized material is "nozzled" in a single direction. If it just goes everywhere, you get no net change in momentum. AND... if it move "a little" then the beam won't be hitting it. Try sending a bowling ball down an alley by hitting it with a BB gun.

Also, in another post, I stated a "rule of thumb", that a rifle in orbit can't fire a bullet fast enough to de-orbit. Your vaporization won't change the velocity enough to notice, orbitally speaking.

Re:Short answers, more like guidelines

[SETIGuy]

Magnitudes are your enemy here. If you shot a .308 rifle out the "back" of the ISS (retrograde to velocity), the bullet probably wouldn't de-orbit.

Actually it would. Quick virial theorem estimate says that bullet would hit the ground even if there wasn't an atmosphere. Shuttle deorbit burns are 250 fps. A .308 round has a muzzle velocity of 2820 fps.

If you shot it straight down (down the radius vector), it would loop around you and come back DOWN at you 1 orbit later and at the same velocity it left!

Not quite. You've given the bullet a small apogee boost, so bullet will have a longer orbital period than the space station and will miss by a good margin. Anyway, those are just details. You've got the basics down.

Re:Short answers, more like guidelines

[Shadow Wrought]

So if I am reading it right, delta-V is the change in velocity. So a Star Destroyer and Paint fleck both have to have their velocity changed the same amount, to the same speed at which they will no longer orbit. The amount of energy required to affect that change can vary substantially?

As to shooting the .308 straight down, would it eventually reneter orbit, just going down a step each time, or would it eventually stabilize in a lower orbit?

Re:Short answers, more like guidelines

[jrvz]

About that aerogel: Assuming LEO spans 1000 km, we have a volume of something like pi*6378^2*1000 ~ 1e11 km^2 to clean up. Assume we put a one-km cube of aerogel into a retrograde orbit*, so its velocity with respect to the junk averages 10 km/s. The time it would take to sweep the volume would be 1e11/10=1e10 s, or about 300 years. Like mopping 30 hectares, or 80 acres, with that cotton swab.

* or many smaller blobs, in a variety of orbits, with an effective cross section of 1 km^2. Each blob has to be thick enough to stop or de-orbit the biggest piece of junk you're worried about.

Re:Short answers, more like guidelines

[pz]

Any material ablated from the surface of an object that's larger than really tiny is going to be ejected in mostly one hemisphere, therefore will impart momentum to the object in the opposite direction. If the object is so small that a laser shot can completely ablate it so the hemispherical assumption is no longer valid, then problem solved!

I wouldn't expect a single shot to be enough to de-orbit non-trivial objects. My understanding -- which is admittedly limited -- is that the best bet for cleaning up space junk is not to deorbit, since that's quite difficult, but to merely lower the orbit sufficiently that atmospheric drag takes over. So multiple ground or water-based laser shots to impart momentum through ablation should be workable.

Re:Short answers, more like guidelines

[Anonymous Coward]

Solve the "how do you apply force at a distance" issue and yer halfway there.

With spooky action at a distance?

Re:Short answers, more like guidelines

[notaspunkymonkey]

I knew i'd backed a winner.. I'm with the clever crowd. I've emailed my family to look at this thread.. my mum wants to know what a spunkymonkey is.

Re:And the winner is

[Scatterplot]

The Columbia disaster happened while entering the atmosphere, which doesn't leave much debris in orbit.

brooms, plural

[starglider29a]

To accomplish this, you would need a vast array of laser brooms. The percentage of objects which travel through your cone of opportunity are a minuscule proportion. You can't cover 180 degrees (the part you can see) of the sky because the distance to the target at the horizon is several hundred km through thermal layers.

The inverse of that minuscule proportion is the number of brooms you'd need.

Forget the energy needed and environmental impact of blasting a terawatt (ok, then... how big?) laser into space. You hit a Vulcan in the eye with that an they will be pissed!

Re:brooms, plural

[Klaruz]

You could put the laser on a boat with a nuclear power source. We already have both technologies. The firestrike laser comes to mind, it can do 100kw with an array of them. You'd need a longer ablation time, but the junk would still start moving.

Re:brooms, plural

[MozeeToby]

You don't need to cover the entire sky at once, every piece of debris you down is one less piece of debris in orbit. It might take large array of brooms several decades to significantly impact the problem but so what? Since they system is ground based maintenance, upgrades, and expansions are all much easier. The power requirements are high but not unrealistically so, 1W of tightly focused laser is powerful enough to ablate many materials so I can't imagine more than a Megawatt would be required to make a significant impact.

Nuke them from orbit

[demonbug]

It's the only way to be sure.

Maybe if we had some space-faring sharks with fricking laser beams...

I'm pretty sure this was a Katamari level...

Where's Spaceball 1 when you need it? Just have to make sure Megamaid doesn't go from suck to blow.

That's enough, I'm done.

Spacewar Pollution

[Doc Ruby]

Military "tests" ("warnings") that destroy orbiting satellites leave junk in orbit that makes future space exploitation more dangerous, costly, and even impossible (vulnerable equipment). It's like the hidden costs of manufacturing (and war) at the surface, which are left as problems for someone else. We humans should quickly force people, governments and corporations which produce debris to either clean it up, or to pay for someone else who cleans it up. We don't want to box in our growing space development just as it's getting started with the pollution from the first few generations.

Re:Spacewar Pollution

[jrvz]

The altitude is important too. The lifetime of a circular orbit varies approximately as the seventh power of the altitude. That means the junk from the accidental collision of Feb 2009 (789 km altitude) and the Chinese test of Jan 2007 (537 km) will stay up a lot longer than that from the U.S. spy satellite shoot-down of Feb 2008 (247 km). Why couldn't the Chinese have picked a lower-altitude target?

The Japanese Saw it Coming

[Bluemumba]

http://en.wikipedia.org/wiki/Planetes

Who knew that a decent, but under appreciated manga that debuted in the late 90s would turn out to be a tale of things to come? :)

Mel Brooks had the Answer! Operation VacuSuck!

[Virtucon]

Time for Mega Maid.. and operation VacuSuck!

Suck Suck Suck!

http://www.youtube.com/watch?v=VptOUWC-Itc

Real Genius

[Marrow]

Doctor Dodd, Hmm Telcom....isn't that the satellite that's raining debris all over Europe?

Planetes & Quark

[AliasMarlowe]

Planetes was very well made, and did not rely on any non-existing technology or speculative physics.
Another dealing with space junk cleanup was the comedy series Quark, which was also excellent, but in different ways.
http://en.wikipedia.org/wiki/Quark_(TV_series)

Vacuum Cleaner

[Audiophyle]

Finally, the vacuum cleaner will actually do what it says it's going to do.

Space Fish?

[Frosty Piss]

Would it require spacemen? Much of this stuff is "tiny". What about some automated or controlled from ground craft that looks like a lage-mouth bass?

"You should see my living room"?

[spike1]

Your living room has junk zipping around at thousands of miles per hour?

Resources

[jandersen]

Hmm, just an idea - maybe we shouldn't try to get rid of this? If we want to establish a larger presence in orbit than the existing space station, wouldn't it be worth collecting this junk and reusing it, since it is already up there? (sorry, just idling)