Astronomers Say: Spew 20 Tons of Dust Into Orbit to Clear the Junk

By Patrick Morgan | April 12, 2011 5:12 pm

What’s the News: The many bits of space junk orbiting Earth, from foil scraps to lens caps to chunks of frozen urine, can damage satellites and spacecraft, which is why researchers have long sought methods to remove debris from orbit. Scientists at the U.S. Naval Research Laboratory have proposed a new way of taking out the trash (in two senses): They want to pump 20 tons of tungsten dust into Earth’s orbit; this dust would exert drag on the junk’s orbit, slowing it down and gradually lowering it until Earth’s atmosphere can burn it up. This bid to protect Earth’s 900 active satellites is controversial because the dust could potentially harm solar panels on satellites and obstruct astronomical measurements, but it’s a handy fix because it doesn’t require ambitious new technology.

How the Heck:

  • The scientists say that their “dust snow plow” was inspired by the natural drag exerted by the Earth’s atmosphere starting at around 900 kilometers: The atmosphere gradually slows down the orbit of junk at this range, pulling debris out of orbit after a number of years.
  • The 20 tons of 30-micrometer-wide particles of tungsten, which is denser than lead, would exert drag on the junk as the dust grains pummel the junk’s surface, decreasing the junk’s orbit to the 900 km level in about a decade.
  • After that, Earth’s atmosphere should burn up both the dust and the junk within the next quarter of a century.

What’s the Context:

  • There’s an estimated 19,000 pieces of trash over 10 cm wide orbiting Earth, and an order of magnitude more that’s less than 10 cm wide. The smaller junk is the most dangerous for satellites because, unlike the larger pieces, they’re not tracked or catalogued, which means that researchers don’t know beforehand if a satellite and a small piece of junk are on a collision course.
  • Scientists say that the dust shouldn’t harm satellites because their “thermal blankets, spacecraft structure, [and] sensor baffles,” are made to withstand dust grains. Plus, they say that satellites could position themselves above the tungsten dust layer.
  • From lasers to explosives, researchers have proposed many ways of cleaning up our space-age mess.
  • By far the oddest bid to reel in junk has been proposed by Japan’s space agency, which wants to team up with a fishing-net maker to rope in debris. Yes, really.

Not So Fast:

  • Unless future solar panels are stronger than current ones, the dust cloud could harm them by scratching their surfaces.
  • There’s still uncertainties as to how a cloud of tungsten in Earth’s atmosphere would behave: The dust could potentially coalesce into a thick band that could interfere with the electromagnetic frequencies that astronomers use.
  • Even if the dust method worked and we pumped our skies full dust right now, it would take a third of a century (10 years to bring junk to the 900 km level and 25 to burn it out of the atmosphere) to see the full effect.

Reference: Gurudas Ganguli, Christopher Crabtree, Leonid Rudakov, Scott Chappie. “A Concept For Elimination Of Small Orbital Debris.” arXiv:1104.1401v1

Image: Gurudas Ganguli et al.

CATEGORIZED UNDER: Space
  • Ryan

    How would this not also degrade satellite structures and protective coatings? If satellites can position themselves above the tungsten layer, then how is this functional. Isn’t the point to remove debris that poses a risk to satellites? If satellites can position themselves above the layer, then the junk the dust is removing seems irrelevant.

  • Mmmm…

    May be shooting blobs of inert gases at specific know crowded spots, not even at orbital speed so the gases will fall back out of the way.
    Some math to be done about the expansion speed of a given blob versus the decceleration of passing thru objects v/s gas density v/s chances to meet the blob, etc… to see if this is realistic.
    Smartest trick would be to have the deccelerated objects to pass thru the same blob at the next orbit at lower altitude, any math whiz around there?

  • Mmmm…

    Next enhancement, multiple staged blobs synchronized for best effects targeted at a given region.

  • Mike

    Hmmm… I wonder what tungsten dust would do to radar.

  • Gregg

    Could be cool for us shortwave listeners…. we’d have an artificial skip layer 24/7/365 :-D

  • http://sites.google.com/site/raisdebris/ John Hall

    As usual the academics are only concerned with space debris posing a threat to functioning satellites and equipment in orbit, yet it poses possibly a far greater threat to everybody here on planet Earth. Speaking for myself I hope it gets no further than being a suggestion, because if they continue to rely on the claim that all space debris burns up during its entry through our atmosphere and then vanishes, they badly mistaken, putting our lives in danger and playing with fire. Not all space debris burns up, in fact a large amount of it doesn’t and manages to impact out Earth at random and has been doing this for many years, often with devastating results. The astronomers are fully aware of this fact, as they are that space debris is our biggest environmental hazard we have ever had to deal with. If you have further interest, put JOHN HALL SPACE DEBRIS in your UK Google search slot.

  • http://kochanezdrowie.blogspot.com/ adept48

    Nie jest to dobry pomysł . Komplikacje mogą być większe .Radosna twórczość naukowców juz ma swoje żniwo .w postaci śmieci w kosmosie .

  • http://none jenn

    I agree with anouther poster,, what is the point of doing this if the satillites can position themselves above the layer of junk to begin with? If the biggest problem is the junk running into the satillite equipment, but they can park themselves above the layer, why not just park them above the layer and let the junk fall when it does?

  • Daniel J. Andrews

    John–I scanned some articles on your site and they’re mostly clippings from newspapers. You are claiming fires, apparent grenade attacks in wars, some earthquakes, destroyed wind turbines, and some downed airplanes are evidence of space debris yet you offer no evidence outside of your opinion that space debris was responsible. That makes your claim only slightly more reasonable than other people who claim those sort of things were from UFOs.

    Do you have photos, have you scoured areas where fires occur with a metal detector, have you taken geiger counters to the areas looking for increased background radiation? Have you done the math to see how big a piece of space debris would have to be to trigger an earthquake? Have pieces of suspected space debris (e.g. the nut that splashed into the pool) being taken for professional analysis? Or even by people who are familiar with the look of objects being dropped from orbit?

    Astronomers have never said all debris is burned up contrary to what you claim. They have done the math, they do know how big something has to be or what it is made of to have a significant probability of hitting earth. Your post sort of implies astronomers are knowingly hiding the facts and knowingly endangering people, including their own families and loved ones.

    You are skirting crackpot conspiracy theory territory with not just astronomers world-wide keeping the secret but pretty much any other scientist or amateur who tracks satellites and knows something about physics, as well as the engineers and other experts who examine damaged equipment. You take pains to tell people it isn’t about UFOs or aliens so I know you don’t want to be seen as a crackpot, but you are going to need a lot more evidence than just newspaper clippings and conjecture.

  • Daniel J. Andrews

    Incidentally, I’m not crazy about the idea of putting up all that dust either. What sort of effects will that have on transmissions and heat input from the sun? Sounds a bit like a geoengineering experiment waiting to go bad. The risk-benefit ratio seems a bit too even IMCUO. *

    * In My Completely Uninformed Opinion. :)

  • http://landonhowell12.tumblr.com/rss Clementine Hires

    Hey.. Awesome blog post. We attempted load this site and it appeared distorted. We was using a iPhone 4g. It may have been this phone though. I am quite postive.. It may be something to it. Anyhoo. The blog article was excellent. Keep up the hard work and We’ll check it out in the near future. Buh-bye….

  • http://sites.google.com/site/raisdebris/ John Hall

    Daniel- Thank you for your interest, I will answer ASAP – John Hall

  • http://sites.google.com/site/raisdebris/ John Hall

    Daniel – Thank you for your interesting questions and comments. My main object including my website, with my displayed efforts over the 23 years, is to try and inspire the public to question the authorities about the possibility of space debris impacts on our planet, not to just accept that it only poses a serious threat in orbit. I want the public to ask this every time there is an incident such as a fire, alleged bomb or alleged shooting for the example of a few. I will try and briefly answer your questions, but feel it is more important that you to ask the authorities rather than my self and hence prove me wrong, but only truly wrong! Yes I have actual photos of space debris, see Skylab on my website. Yes I am familiar with the look of objects. No I have not done maths to see how many pieces it would take to cause a quake, but would say one large piece would suffice. Yes I did send some for analyses, but received no reply? Yes I did buy a Geiger Counter after considering Operation Morning Light, but thankfully my immediate area proved clear, of course not all space debris will be metal or radiation active. I do not accept that all space debris burns up, no I have not done maths, I have only observed the amount of incidents that have occurred and continue to occur globally and daily, like today in Morocco for instance 29th April. On the other hand, the scientists have done their maths and know full well they are hiding the facts and I will continue to challenge them on this. The survival of space debris whether it is natural or unnatural is not only dependent upon its size and a UFO is not a UFO if it is identified. The authorities are quite prepared to admit that space debris is a problem in orbit, but not with the possibility of Earth impacts, in fact it is rarely mentioned in this aspect. My email address is on my website. Regards John Hall RAISD

  • Messier Tidy Upper

    Interesting idea. Could the tungsten dust have any effect on reducing solar radiation being intercepted and thus be a potential aid in reducing or fixing Global Warming as well?

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