Please create an account to participate in the Slashdot moderation system

 


Forgot your password?
Close
typodupeerror
×
Space

Traffic Cops for Space 297

Posted by michael from the alternate-side-of-the-orbit-rules-are-in-effect dept.
The NY Times has a good story about a push for international action, via the UN, on the growing problem of space debris. Includes a pretty picture of a space shuttle window that got nailed by a fleck of paint.
This discussion has been archived. No new comments can be posted.

Traffic Cops for Space More

Traffic Cops for Space

Comments Filter:

  • The worst thing about space junk (Score:5, Interesting)

    by James_Duncan8181 ( 588316 ) on Tuesday February 18, 2003 @07:24PM (#5330364) Homepage
    ...is that it is a chain reaction. It is relatively safe up there at the moment, but if we ever get a satelite (say) hit then the debris caused by it's disintergration will cause further problems. I am sure those with even the slightest imagination can see the ongoing process that happens next. You want to go up after that has been becoming exponetially worse for a year or two?

    • Re:The worst thing about space junk (Score:5, Informative)

      by Forgotten ( 225254 ) on Tuesday February 18, 2003 @07:45PM (#5330563)
      This is the "critical mass" problem, where at a certain point all the junk colliding with itself creates a self-propagating chain reaction. This has two effects - more smaller bits are harder to track, of course (particularly because there's a resolution limit that determines the smallest size per distance that ground radar can track), but also a spreading of the material into wilder orbits and outside the two bands where it's currently still concentrated. The shuttle & ISS altitude, for instance, is relatively clear right now. Once the chain reaction starts (and some people think it already is in the chaotic early stages) this will no longer be true, and all space travel will become a lot more difficult.

      The NYT article only slightly alludes to this with the "10 or 20 years" bit, but it is the real problem. As you note it's a question of linear vs. exponential growth - manageable or unmanageable. There is a tipping point, and regardless of where it is, it's folly to keep approaching it without SOME sort of cleanup scheme. So save your chewing gum; it's going to come in handy one day for the great space sweepup.
      • There is a tipping point, and regardless of where it is, it's folly to keep approaching it without SOME sort of cleanup scheme.

        Just like CO2 emissions and global warming... unfortunately, procrastination is a way of life, not just in college, but also for big, real-world problems.

      • Look on the bright side. What makes Saturn the coolest looking planet in the solar system? Its rings!

        Soon, through a process similar to that which created Saturn's rings, Earth could have its own rings. And being made of mostly metal, plastic and paint, our rings would be especially shiny and colorful.

  • Space cr4p (Score:3, Interesting)

    by saitoh ( 589746 ) on Tuesday February 18, 2003 @07:24PM (#5330371) Homepage
    I've wondered about this as a problem for a while. Wouldnt it be advantageous to the UN to clean up a majority of the stuff (manmade) in space to prevent further problems such as the speculated involvement in the recent Columbia crash?

    On that note, has anyone else wondered what it would be like to take landfills, package them in rockets, shoot them to the sun and see what happens or am I the only one who has strange dreams like that. ;-p What are the odds something like this becomes viable?
    • Let's try to be somewhat accurate, it will be the US cleaning it up.

    • Re:Space cr4p (Score:5, Interesting)

      by kfg ( 145172 ) on Tuesday February 18, 2003 @07:31PM (#5330439)
      What happens is relatively unspectacular. They vaporize. Quietly. They don't blow up or nothin'.

      The spectacular part is the approximate cost of $25k /kg.

      Do you know how much a landfill weighs?

      So we don't even have to go into the fact that the overall enviromental impact of doing this is greater than a properly managed landfill.

      KFG
      • aside from launch problem fears...

        how much is the TCO on nuclear/toxic waste? (stored in Yucca Mtn or not)

        • Nuclear stuff isn't launched into orbit because of something like Challanger/Columbia. While both events are a tragedy in itself, a nuclear filled shuttle that would explode would be like chernobyl + Columbia.

          However, to reduce the TCO... Mass drivers anyone?

          • i understand the safety issues about launching toxic waste....but i wonder what the total storage cost ends up being.....if we were able to have some sort of reliable space-launch system (reliable to the point of probability of disaster being lower than the current storage pools) would it cost less than current storage means?
    • On that note, has anyone else wondered what it would be like to take landfills, package them in rockets, shoot them to the sun and see what happens
      Nothing would happen. The stuff would burn up and that would be the end of it. In fact, the whole earth could plummet into the sun and not cause a hiccup. Then why don't we do it? I'd say that the financial effect would be quite a bit less trivial.

    • Re:Space cr4p (Score:5, Funny)

      by EvilStein ( 414640 ) <.ten.pbp. .ta. .maps.> on Tuesday February 18, 2003 @07:48PM (#5330589)
      It's more useful to launch prison inmates into orbit.

      Maybe we can launch them towards Mars so they can colonize it. Hey, it worked for Australia, didn't it? It's a cool place! ;)

    • Re:Space cr4p (Score:2, Interesting)

      by ketilf ( 114215 )
      How do you suggest this space debris is cleaned up? It is zipping back and forth at VERY high speeds. Perhaps a spacecraft could catch one piece, or maybe even 2. How many more pieces would that spacecraft generate on it's way? I think this is highly problematic, and not likely to happen any time soon.

      If not, I'm sure someone who knows better will point out why I'm wrong.
      • You make a solid block of something really dense that is as shatter-proof as we can make, like bulletproof glass or something (the kind that it takes an hour to get through with an axe). Then you stick it in the 'dirty' orbit and let all that garbage ram into it.
        • You make a solid block of something really dense that is as shatter-proof as we can make, like bulletproof glass or something [...]
          Seriously, why make something so hard? I think something gelatinous or organic would work better. Say, a radius = 10 meter sphere of chewed-up chewing gum. Something with enough mass so that no debris particle could penetrate all the way through it, and something amorphous so that impacts wouldn't cause more debris to break off. Plus, something like you describe would cost a shitload to ship up to LEO. Something with less mass, but with enough stuff there to stop particles, might be better.

          Send up the gum!

      • ...and run it around the cluttered orbits backwards for a year.

    • Re:Space cr4p (Score:5, Funny)

      by Tackhead ( 54550 ) on Tuesday February 18, 2003 @08:13PM (#5330801)
      > Wouldnt it be advantageous to the UN to clean up a majority of the stuff (manmade) in space to prevent further problems such as the speculated involvement in the recent Columbia crash?

      REUTERS - Feb 1, 2023:
      UN Secretary General Clinton said in a speech today that while the loss of the privately-launched and operated "Armadillo" space plane last weekend is regrettable, but that the United States is obliged to "give the collections process time to work", and called for the UN Space Council to pass a resolution calling for the complete cleanup of space debris by 2033.

      BACKGROUND: The UN Space Council was formed following the loss of Shuttle Columbia 20 years ago. After passing resolutions calling for permanent funding form the UN, it promptly passed a series of resolutions concerning the issue of space debris in low earth orbit.

      Following the loss of Shuttle Discovery to space debris in 2005, the UN Space Council passed Resolution 1042, calling for a programme that would investigate the feasibility of LEO debris collection.

      In response to the stranding of the crews of the ISS and Shuttle Atlantis due to damage a surprise recurrence of the Leonids in 2006, the UN Space Council passed Resolution 1334, lauding the process of investigation, and calling for additional time to study the problem.

      Rescue shuttle Endeavor was launched one month later, but failed to make it into orbit after the main engine was punctured by space debris. All three vehicles were loss. This catastrophe prompted Resolution 1349, demanding an extension of the deadline for submission of the debris collection feasibility study, and an expansion of the study to include weapons of meteoric destruction below the tropopause.

      Secretary-General Clinton hailed this week's decision by the UN Space Council to proceed on another resolution, and in his speech, reminded the world that despite the Armadillo tragedy, it was due to the diligence of the UN Space Debris Collections Process that there had been no losses of manned spacecraft since the loss of the last Shuttle in 2006.

      A furious Tom Paine, former NASA administrator during the Apollo years, was ejected as he attempted to disrupt the proceedings from the visitors' gallery. Rumors that the words "You sick bastards, the reason NASA hasn't lost a manned mission since the loss of the last shuttle in 2006 is because it hasn't launched anything since then! For fuck's sake, it hasn't even frickin' built a new manned vehicle based on post-1982 technology!" are completely false.

      UN Secretary-General Clinton kept his composure despite the disruption in the gallery, and concluded his address to the UN Space Council without further incident.

      His call for a new UN Space Council resolution to "let the debris collectors assess the situation" has received great support, particularly from representatives of Arianespace.

    • Re:Space cr4p (Score:4, Insightful)

      by oh ( 68589 ) on Wednesday February 19, 2003 @12:14AM (#5332353) Journal
      Wouldnt it be advantageous to the UN to clean up a majority of the stuff (manmade) in space to prevent further problems such as the speculated involvement in the recent Columbia crash?

      Off the top of my head there are only a handfull of space programs worthy of the name, US, Russia, China, Japan and the EU. I think most of the members of the UN have other things on their mind, like starvation, AIDS, war, terrorism, and general economics. I'm sure that space junk isn't high on the priority list.
  • ...is useless. The small size of objects large enough to do serious damage means that they're probably extremely difficult to track. What else is there? Design a giant space dump truck to scoop it all up? Sounds more expensive than new shuttles.
    • Please remember this has to be the kind of dump truck that can withstand being hit by screw sized projectiles at maybe 1500 miles an hour. You want to carry it up? ;)
      • screw sized projectiles at maybe 1500 miles an hour

        Actually, I had read somewhere that manmade space junk orbits at around 22,000 miles per hour, while natural space junk orbits at around twice that speed. So depending on the direction of your orbit, and the space junk's orbit, you could theoretically be coming up against some space junk at around 88,000 miles per hour.
    • Sounds more expensive than new shuttles.

      So, stop polluting space. And while you're on in, also stop polluting your local neighbourhood, the air that you breath and the water you drink.

      Cleaning up afterwards is always more expensive than preventing it from polluting in the first place. But then, you don't make friends with reminding people about it.

  • Hrm (Score:2, Interesting)

    by unterderbrucke ( 628741 )
    I don't understand why this isn't being looked into more as a reason for the Columbia disaster. If you look at the latest issue of US News, on about page 8, they have a handy dandy map of space debris. It looks like the whole earth has a white halo due to the sheer amount of it.

    • Misleading pictures (Score:4, Insightful)

      by freeweed ( 309734 ) on Tuesday February 18, 2003 @11:05PM (#5331950)
      Computer-simulated pictures of orbiting space debris suffer from the same problem that images of our solar system do:

      Each individual 'thing' (piece of debris/planet) is incredibly tiny compared to the size of the background object (Earth/the solar system). If they showed an actual scale model of the solar system on your (for example) 1600x1200 screen, even jupiter would be well under a pixel wide (in fact, Jupiter's diamater is about 1/40,000th the size of the mean distance from Pluto to the Sun).

      Same thing for Earth orbit space debris - sure, there are tens of thousands of objects up there - but the biggest thing we've ever sent into space is only a few hundred yards long, and the vast majority of these things measure in the inches. The Earth is more than 12 MILLION yards wide.

      Point is, you wouldn't see anything on any real scale model of either the Earth or the solar system. They artificially blow up the little things so it has some relevance to us feeble humans. Not that this lessens the danger from space debris, mind you - it's just nowhere near as bad as it looks from the pretty pictures.

  • Clearly, (Score:2, Funny)

    by Anonymous Coward
    We must focus on our Energy shields and Deflector beams. C'mon, NASA. Get it together.

  • Lots stories today... (Score:3, Funny)

    by Repugnant_Shit ( 263651 ) on Tuesday February 18, 2003 @07:28PM (#5330404)
    I think the editors are trying to push the Tom's Hardware dupe off the front page :)

  • Don't wanna register at NYT? (Score:5, Informative)

    by Greedo ( 304385 ) on Tuesday February 18, 2003 @07:28PM (#5330410) Homepage Journal
    Use user/pass: slashdot_coward

  • Much better photos here (Score:4, Informative)

    by EggMan2000 ( 308859 ) on Tuesday February 18, 2003 @07:28PM (#5330412) Homepage Journal
    This is pretty old news but it's got better pics [si.edu]. Norad has been tracking space trash for decades. Fact of the matter is, there is trash up there, yes it can hurt you or the shuttle, or the hubble, etc. But the odds are very slim for most orbits. The hubble got hit with a little piece once, but the odds are pretty slim anything we send up will get hit by debris.
    • The whole point is that the odds don't stay slim. "Orbital cascade", as mentioned in other posts in this thread. One big bit becomes many smaller bits, those smaller bits might each render another satellite/astronaut/flying saucer into lots more small bits, and so on. Something you can only hope to avoid, since there's no great way of clearing it up once the problem becomes serious.

  • The UN? Is that a joke? (Score:2, Insightful)

    by Anonymous Coward
    How could a group of utterly clueless politicians do anything useful about space junk? They'd form a committee and assign a bunch of 3rd-world communists to blame it all on the US.

  • It is a problem NOW. (Score:2, Interesting)

    by damu ( 575189 )
    Yes, many of the trash right now is relatively small, however when doe sit get "big" enought to clean it, if you wait and wait until it really becomes a problem, then it is already to late. And this has nothing to do with the Columbia, the trash is in a totally different part of the atmosphere.

    dam(u)

  • What we really need... (Score:3, Interesting)

    by iiioxx ( 610652 ) <iiioxx@gmail.com> on Tuesday February 18, 2003 @07:32PM (#5330459)
    ... is orbital garbage collection. When you see the damage a paint chip can cause, imagine the damage a 1" steel ball bearing (moving at 50,000mph) could do.

    Here's an idea: equip a spacecraft with a giant kevlar net and put it into orbit to collect debris, then jettison the debris bag to impact the Moon. It's just barren rock sitting there unused, the Moon would be the perfect orbital landfill. Hmm... kind of an Orbital Quicker-Picker-Upper. Maybe we could get corporate sponsorship from Bounty to offset the cost...
    • Actually, a ball bearing moving at 50,000mph is either A. totally harmless, or B. the least of the concern.

      A) if it from a terrestrial craft, harmless because 50k mph is way past escape velocity, and so would be moving away from earth, never to return.

      B) the least of our concern, because, if it was coming towards the earth at that speed, it is not of terrestrial origin. The proven fact of aliens waould far outshadow the destruction of a mere spacecraft. OTOOH, it might start the first (albeit short) interplanetary war.

      Your point is well taken though. A fast moving, small hard object could very easily bring down a spacecraft.
      • Those damned aliens and their stealth ball bearing technology. From what I've read in the Enquirer, they have apparently setup two giant posts, one each on Pluto and Charon. As soon as they construct a big enough rubber band to string between them, they will launch their devastating onslaught and our cosmic goose will be cooked.
      • A) if it from a terrestrial craft, harmless because 50k mph is way past escape velocity, and so would be moving away from earth, never to return.
        I don't think so. Nothing says debris from a collision in LEO has to fly outward, away from Earth. Stuff going out at vectors closer to tangent with the orbit might enter eccentric elliptical orbits. I haven't run any calculations, so I don't know about the 50,000 mph, but you could get some pretty fast shit with an apogee coinciding with Earth orbit, making collision with stuff in that circular orbit possible.

        Anyone who's taken physics more recently than I have, feel free to tell me where I'm wrong.

        • What part of escape velocity is hard to understand?

          Earth escape velocity is ~25,000 mph.
          Solar escape velocity is ~93,600 mph

          Newton tells us that an object will tend to travel in a straight line, unless acted upon by an external force. Such external force in this case being gravity.

          50k mph is way above escape velocity for earth. The earth cannot capture that object. Tangental vectors be damned.
          The Sun, having a much higher gravity, is a different story. An object with a 50,000 mph initial velocity could possibly enter some highly elliptical solar orbit, but not an earth orbit.

          The possibility of that object coming back around and actually hitting anything is very remote. Basically, if you somehow impart that 50k mph velocity, you end up with a comet at best. It may come back in a hundred (or thousand) years or so.

          Impart a 17,000 mph initial velocity, and now we're talking about something that can possibly remain in an earth orbit.

  • The UN? (Score:5, Funny)

    by Will_Malverson ( 105796 ) on Tuesday February 18, 2003 @07:32PM (#5330460) Journal
    Given that Libya chairs the UN human rights committee, and Iraq is scheduled to chair the disarmament committee later this year, is Elbonia going to chair the space debris committee?
    • Humor registered, but for the record, those appointments at the UN are rotating, and Iraq announced a few days ago that it will not be chairing the disarmament committee when its turn comes, as reported in this Reuters article. [alertnet.org]

    • Re:The UN? (Score:2, Interesting)

      by pnatural ( 59329 )
      is Elbonia going to chair the space debris committee?

      The space debris committee is a long way off. First, the UN must pass at least a dozen toothless resolutions over a ten-year period calling for the voluntary dismantling of space debris.

      When that doesn't happen and the USA decides it's a matter of national security to do something about it, France, Germany, and other dictator-loving countries will protest loudly that the space debris must be inspected more vigorously (which is a sham, of course, as French space companies a vested interest in maintaining their billion-euro contracts with the space debris).

      Actors will protest. "What about the children of the space debris?" they will ask. Communist and socialist sympathizers, along with their friends at CNN, will complain loudly "America is ignoring the voice of the world community!" Dan Rather will come to our rescue when he proclaims "Like it or not, he's still our President". Of special note will be the [un]American Democratic Party, which will profess to have a plan of it's own that calls for billions and billions of taxes (gathered only from the rich, of course) to be spent on a government program investigating the habitat of space debris.

      And finally, a good ol' boy from Texas will have enough balls to do something about it. The rest of the world will hate him for it, even if they do sleep easier.

  • Kinetic Energy... (Score:5, Interesting)

    by Aesculapius ( 147375 ) on Tuesday February 18, 2003 @07:33PM (#5330468)
    It would be extremely difficult to track small pieces of debris. That's why you have to get rid of junk when it's big....before it becomes little pieces.

    Remember, the energy a moving mass has (kinetic energy) is defined as:
    Kinetic Energy = 1/2 * mass * velocity ^ 2

    What that means is that velocity is much more important than mass. To give an example, a small bolt about 1/4" in diameter traveling at 17,500 mph has the same kinetic energy as a bowling ball traveling at 60 mph.

    Yikes!

    • Re:Kinetic Energy... (Score:5, Informative)

      by cybercuzco ( 100904 ) on Tuesday February 18, 2003 @08:52PM (#5331063) Homepage Journal
      Remember, the energy a moving mass has (kinetic energy) is defined as:
      Kinetic Energy = 1/2 * mass * velocity ^ 2

      um, its a bit more dramatic than that. You should recheck your calculations. 60 mph is about 26 m/s, orbital speed is approximately 7600 m/s for a bolt mass of 50 g (.05 kg or about .11 lbs) the kinetic energy is roughly equivalent to 4000 kg at 60 mph or about 8 tons ( in lbs tons) so imagine getting hit by an 8 ton truck that has the cross section of a bee. It would go right through a space shuttle or anything inbetween.

    • Good thinking. I know you acknowledges this already [slashdot.org], but it's far worse than you mention: I ran the numbers a bit, and assuming a 10 pound bowling ball, that 'bolt' would have to weigh only 53mg to have the same KE.

      Using a density of steel of 7.87g/cc, [pack730.org] that would be 6.775 mm^3. or 1mm x 1mm x 6.775mm: about the size of the sheath on the end of my mechanical pencil.
      Or about the size of the tiniest bolts in my watch.

      Or, probably the size of that paint flek -- we certainly can't tell from that awful picture because there is no sense of scale!

  • What about other planets? (Score:5, Funny)

    by Anonymous Coward on Tuesday February 18, 2003 @07:34PM (#5330488)
    You think Earth's got problems? Imagine the space debris problem in the Endor system. I mean, hell, the entire death star exploded - and that thing was friggin' HUGE! I mean, there you are, heading towards a nice vacation on Endor's forest moon, planning on partying down with the Ewoks, when all of a sudden - WHAM! little Palpatine bits are impacting against your YT1300 cockpit windows. I wouldn't want to be the clean-up crews working the Alderaan, Yavin, or Endor star systems. You'd be there for as long as it takes a Sarlaac to digest a barge full of Hutts...

  • Space Debris and the ISS (Score:5, Interesting)

    by luzrek ( 570886 ) on Tuesday February 18, 2003 @07:46PM (#5330575) Journal
    The ISS has some interesting features to make it space debris resistant. Apparently the sleeping quarters (and hopefully anything else that has humans in it) has several layers of high strength fabric separated by quite a bit of empty volume in order to soak up the kinetic energy of space debris as it will inevitably hit the station. Of course, this approach is difficult for a launch or re-entry vehicle since the gaurd would have to be deployed after launch and retracted before re-entry.

    • Re:Space Debris and the ISS (Score:5, Funny)

      by kyletinsley ( 575229 ) on Tuesday February 18, 2003 @10:34PM (#5331730) Homepage

      Apparently the sleeping quarters ... has several layers of high strength fabric separated by quite a bit of empty volume in order to soak up the kinetic energy of space debris as it will inevitably hit the station.

      Ahhh yes, the good old "bed sheet deflector shield"... I've used those before in the past. Kept those high-velocity monsters from my closet at bay quite well!

  • ... a potential victim, or a potential cleaner?

  • Just Say No (Score:3, Funny)

    by scotay ( 195240 ) on Tuesday February 18, 2003 @07:54PM (#5330645)
    Before long, those bastards will have a union and a quota.

    Wait until the end the month, when it will be tickets for speeding over a school zone or for improperly parking the orbiter when you KNOW you were between the lines and there was enough time left on the meter.

  • Magnets? (Score:3, Interesting)

    by jonman_d ( 465049 ) <nemilar&optonline,net> on Tuesday February 18, 2003 @07:56PM (#5330663) Homepage Journal
    Is there any reason that we can't send up a satilite with some manuvering thrusters, with an electronic magnet attached to it, which we could activate/deactivate? Then we could just manuver it into positions near debris, activate the magnet, dump it into some sort of cargo bay, and once it's full, have it burn up in the atmosphere.

    Couldn't be too expensive, and sounds pretty simple...?
    • One of the really really big problems with a space garbage collector is the issue of fuel. In order to move in space one must rely on rockets (since you only get thrust from conservation of momentum). The rockets on modern spacecraft fall into two camps. First, the old, chemical reaction and nozzle type. These provide a pretty good amount of thrust by use up a huge amount of fuel. The second is the microwave powered xeon atom emitting type. These are much more efficient because they allow the spacecraft to use solar energy for propultion. Unfortunately, they don't offer a good deal of thrust.

      In order for a space garbage collector to work, it would have to go chasing after a large number of peices of junk moving in different orbits. In order to catch a particular piece of space junk, it would have to both match the junk's velocity and possition, then fire up its engines again and go after some other peice of space junk. Even if one could come up with a very efficient algorythm for chasing down the junk, the garbage collector would have to have its engines on nearly all the time. If it used a traditional rocket, it would run out of fuel in at best a couple of days. If it used the microwave heated xeon type it would be collecting garbage for centuries if not millenia.

  • With the UN in charge (Score:5, Insightful)

    by rossz ( 67331 ) <ogre&geekbiker,net> on Tuesday February 18, 2003 @07:58PM (#5330675) Journal
    With the UN in charge, if someone broke the rules the UN would say, "Stop! or we'll say 'Stop!', again".

    The UN has proven on numerous occassions that they are nothing but pencil pushing bureaucrates who, at best, do nothing, but all too often simply make the situation worse.

    Look at Rwanda. Given the job of protecting 100,000 unarmed refugees, the UN security force DID NOTHING when a warlord's army arrived and proceeded to slaughter every man, woman, and child.

    So now someone wants to give the UN the job of reducing space junk? No thank you, I'd rather take my chances with out their help.

  • No Registration NYT Link (Score:3, Informative)

    by NewWaveNet ( 584716 ) <me@austinheap.com> on Tuesday February 18, 2003 @08:04PM (#5330738) Homepage Journal
    Am I the only person that's noticed all you have to do is slap ?partner=GOOGLE on the end of a NewYork Times URL and it won't force you to register? Point in case for this article:

    http://www.nytimes.com/2003/02/18/science/space/18 TRAF.html?...&partner=GOOGLE [nytimes.com]
  • Quote from the article (since I know most of you didn't read it)

    In 1961, sensitive American and Soviet radar watching for World War III detected only 50 manufactured objects, burned-out rocket stages and the like, circling the globe.

    The list of orbiting objects tracked by an array of military radars and telescopes now tops 10,000, but these are only the bits large enough to be routinely tracked -- things larger than a softball.

    I would imagine that radar has become a bit more refined in the last 30+ years, so this statistic should be taken with a grain of salt.

    ps, it's somewhat offtopic, but does anyone have a link to stats regarding the ratio of visible natural meteors flaming through the atmosphere vs. man made ones doing the same?

  • Relative velocities? (Score:5, Interesting)

    by Theaetetus ( 590071 ) <theaetetus@slashdot.gmail@com> on Tuesday February 18, 2003 @08:51PM (#5331057) Homepage Journal
    Even a one-centimeter pellet, the width of a fingertip, can destroy a spacecraft traveling at a typical orbital speed of 20,000 miles per hour or more, experts say.

    Small question, having heard for a while about the problems of space junk...
    If that one-centimeter pellet is going 20,000 mph faster than the shuttle, wouldn't it be in a much higher orbit? And if the shuttle is going 20,000 mph faster than the pellet, wouldn't the pellet be in a lower orbit (i.e. on the ground)? And if they're both going at 20,000 mph... what's the problem?

    I know that LEO is getting pretty damn crowded with junk, but what are the real differences in relative speed at that altitude/orbit? Without the 20,000 mph FUD?

    -T

    • Re:Relative velocities? (Score:5, Informative)

      by EvilBuu ( 145749 ) <EvilBuu&yifan,net> on Tuesday February 18, 2003 @09:08PM (#5331165) Homepage
      As previously stated, the problem is when that pellet is going 20,000mph in the opposite direction of the space craft. 40,000mph whammo.

      On a related note, anyone here ever play RIFTS? I remember getting the expansion book describing whole space colonies which hadn't contacted the surface of the Earth for hundreds of years due to massive interweaving clouds of space crap that destroyed any ship attempting to land (or presumably move within communication distance).

    • circular vs. elliptical (Score:3, Informative)

      by Anonymous Coward
      for circular orbits, yes. Actually, for any orbits, yes, the semi-major axis goes as the cube for the period of the orbit squared. Kepler's 3rd law.

      But, a highly elliptical orbit will have an object moving SIGNIFICANTLY faster at it's perigee (closest point to sun) than a corresponding circular orbit at the radius of the perigee. Kepler's 2nd law (equal areas swept out in equal times).

      Just for completeness, Kepler's 1st law says bound gravitional systems move in elliptical orbits, with the gravitational source at one of the focii.

      So, yes, it is quite possible that at any point one can encounter an object moving significantly faster.

      • But, a highly elliptical orbit will have an object moving SIGNIFICANTLY faster at it's perigee (closest point to sun) [...]
        Your post is so informative, I feel it necessary to nitpick. Perigee and apogee deal with ellipses around the Earth; for the Sun, the corresponding words are perihelion and aphelion.
  • This article brings to mind a major, but unnoticed fatal flaw in Regan's Star Wars program which sought to put killer sattelites in space to protect the American People: all an enemy needed to do to take said network out was launch a handful of rockets to the same orbit to explosively release simple payloads of (many) ball bearings. No cost-effective defense against it.
    • [...] all an enemy needed to do to take said network out was launch a handful of rockets to the same orbit to explosively release simple payloads of (many) ball bearings.
      True. But the function of Star Wars would have been to lessen or eliminate the impact of a surprise Soviet ICBM strike on the US by taking out as many missiles as possible while they were in transit. IOW, the satellites would have been meant to prevent a single attack (presumably after which, our own ICBM strike would have been carried out and annihilated the USSR's nuclear attack capability). The Soviets wouldn't have simply been able to clandestinely launch a debris rocket, let the laser sats get destroyed, and launch a strike of their own. It would take time for the satellites to get hit. This entire process could be long and drawn out, with the US discovering the Soviet debris rocket, engaging in diplomatic maneuvering, threatening nuclear war, launching more sats, blah blah blah...

      Your plan would work, inasmuch as carefully-placed space debris could take out everything in a certain orbit. But:

      • If the satellites were equipped with maneuvering thrusters, they could use them to accelerate perpendicular to their orbit and the Earth's radius (e.g. tangent to the meridian directly downward from them), so that their orbit would be modified so its great circle would only cross the debris' orbit twice per orbit.
      • Now that I think of it, that idea sucks, and if the satellites had maneuvering thrusters, they could use them instead to boost themselves into a higher orbit.
      Also, would the soviets have known which satellites were the Star Wars ones? We could have kept their launch secret, and interspersed them with communications sats, so the Soviets wouldn't have been able to distinguish between commercial and military sats.

      Anyway, if the US had launched laser sats, the Soviets would have eventually launched them too. If anyone has played Sid Meier's Alpha Centauri, we then would have had a situation like the SMAC endgame, where a number of factions have laser satellites in orbit, each with a certain chance to stop an attack directed against it.

      Wow, I really need to load up Civ 3 and toss some nukes around.

  • Scientific illiteracy strikes again (Score:3, Insightful)

    by CaptainCarrot ( 84625 ) on Tuesday February 18, 2003 @09:17PM (#5331226)
    From the article. I've compressed the quote; in the original, each sentence inexplicably occupied its own paragraph. It's about the paint chip that struck a window on the Space Shuttle.

    A closer look revealed radiating webs of damage in the outermost of three layered panes of heavy glass. When the window was removed back on Earth, the embedded mote was found to contain traces of aluminum and titanium. It was a fleck of paint, most likely from a derelict rocket casing. If it had been slightly heavier, the window could have imploded, killing the crew, experts concluded.

    "Imploded"? I'll bet the "experts" concluded no such thing, if they were worthy of the name. With 1 atmosphere of pressure inside the vehicle and 0 pressure outside, the window would have exploded, not imploded. The writer was probably thinking by analogy with a CRT, which will indeed implode if shattered because there's a vaccuum inside. On orbit, the vaccuum is outside.

    Sheesh!

  • Not the UN (Score:3, Insightful)

    by Chacham ( 981 ) on Tuesday February 18, 2003 @09:23PM (#5331261) Homepage Journal
    While space management may be a good idea, allowing the UN to do it is a very bad idea.

    IMO, there is not really anything the UN ever did that was good. I don't mind nations getting together for large scale projects such as this, but the UN is a waste of money. I blew of some steam in a journal entry [slashdot.org].
  • Seriously, doesn't the technology exist for a rudimentary thing like this by now?

    Would greatly increase safety 'up there'.


  • Send in Captain Quark [yesterdayland.com].
  • "routinely sweep a 30-mile box"
    "20,000 mph"
    "softball"

    30 miles / 20,000 mph = .0015 h = 5.4 s

    So, basically, the tech on the radar will have enough time to tell his supe that the spacecraft is about to be annihilated.
  • who's been playing paintball at the ISS?
  • The UN can barely manage itself, let alone pull the nessisary resources together to enact such a project. In the end, the bulk of the initiative would be shouldered by the US or Russia. The UN wouldn't be doing but playing the proverbial supervisor. Heck, maybe they could send inspectors into sp-- Oh! MwaAhahahahah!!!

  • "Why don't we just catch it?" (Score:3, Informative)

    by wowbagger ( 69688 ) on Wednesday February 19, 2003 @09:29AM (#5334121) Homepage Journal
    This is addressed to all the posters who posted varients of "Why don't we just catch all the junk?"

    Since you don't understand the problem, allow me to offer to help you understand it.

    Come to my house. We'll go into the back yard, and I'll shoot at you with my AR-15. You catch the bullets. That's MUCH easier than catching orbital debris - the bullets are much larger (40 grains is roughly 2 grams) and MUCH slower (3600 feet per second is roughly 1 km/sec). Also, you will know ahead of time where the bullet will be - I'll make it easy and aim right at you.

    Now, when you can catch those bullets, you can move up to orbital debris - much smaller, much faster, and moving on unknown trajectories.

    "But we'll just use a big Kevlar net! We won't have to know where the bullets are heading!"

    Fine. Here's your Kelvar net, about 1km on a side. It will only take about 1000 years to catch most of the debris, since "Space is big. Really really big. You can't believe just how mind-bogglingly huge space it".

    To simulate the launch, let's go to Colorado Springs. I'll pay your way into Pike's Peak. Go to the top of Pike's Peak with the net - it's only a couple of tons. No, you cannot drive - you have to walk. I'll wait. That will help you understand the COST of putting your big net into space.

    DON'T take what you see on Star Dreck as reality - space is HUGE, junk is SMALL. This is not a simple problem.

Slashdot Top Deals

He has not acquired a fortune; the fortune has acquired him. -- Bion

Close