back to article New satellites could cause catastrophic space junk collisions

Broadband satellites could lead to an explosion in the volume of space junk, a British scientist has said. Dr Hugh Lewis, a senior lecturer in aerospace engineering at the University of Southampton, said that the rise in orbital traffic could create a 50 per cent increase in the number of collisions between satellites. Such …

  1. Adrian Midgley 1

    Plugging satellites together

    So there are fewer, larger, satellites would appear to be a strategy.

    And adding Lego bricks of thruster clusters on each end could maintain function.

    We thought we'd build one space station, then Clarke indicated 3 so let's head back toward that.

    1. Jon 37

      Re: Plugging satellites together

      The problem is the speed of light.

      Four big communication satellites in geostationary orbits can cover the whole world (except the poles). E.g. Inmarsat's original satellites follow this model. Unfortunately, geostationary satellites are a long way away from the Earth, so signals travelling at the speed of light take at least a quarter of a second to go from Earth to the satellite and back to Earth. For telephone conversations, or TCP/IP networking, that delay is very long and causes problems.

      To reduce the delay, you bring the satellite closer to Earth. That reduces the area it can cover, and also means the satellite is travelling across the surface of the earth instead of appearing motionless. So you need lots of satellites to get coverage.

      With geostationary satellites, a missing satellite means that a fixed area of Earth doesn't get any coverage, which is acceptable - you can just sell your service to the people who have coverage, and that's how Inmarsat started with a single satellite. But because these closer satellites are moving, so the area of no coverage moves, so everyone everywhere complains about the regular dropouts. So with these new constellations, they will have to launch all of the satellites to get global coverage all at the start, plus they need some in-orbit spares so failed satellites can be replaced quickly.

      Also, the smaller the spot that's covered the higher the bandwidth can be. Simplistically, if each satellite can do 1 gigabit/sec, then 50 satellites gives you a total of 50x the bandwidth compared to 1 satellite. (In reality it's not that simple, the gain isn't that big, but the general point stands). You can also reuse radio frequencies on satellites that are "far enough" apart, the same way that mobile base stations reuse frequencies. So 50 satellites can be significantly faster than 1 satellite, with the same frequency allocation.

  2. Tom Paine Silver badge

    The boffin quoted in the final par seems to be under the impression commercial satellites are a new phenomena...

    And the claim that there might be 50% more collisions is pretty unexciting when you remember there's only ever beena single incident of two satellites colliding (afaik?)

    1. DougS Silver badge

      50% increase

      When I read that I was wondering what exactly a 50% increase would entail, since as far as I knew satellite collisions weren't a thing. Maybe he meant there would be a 50% increase in the risk of a collision?

      Obviously the more stuff that's up there, the more difficult it is to keep track of and if satellite A has its orbit adjusted to avoid space junk and that isn't properly coordinated with everyone else, it might find itself colliding (or more likely having a near miss with - space is big!) satellite B that also had its orbit adjusted to miss some space junk.

    2. David Webb

      The thing is, it doesn't need lots of sat's smashing into each other to cause a problem. One sat getting wrecked by a missile (see China) puts up lots of small debris into orbit, that lil bit of space junk hits another sat at high speed and causes that to go KABOOM and puts even more debris into orbit, which in turn hits another sat..........

      Eventually we will have the problem of small bits of junk flying around the Earth at very fast speeds, lots and lots of small bits of junk, so when we try to send up some new sat into orbit it will get hit by the debris and we will forever be trapped on this tiny planet because any launch into space becomes impossible because the amount of debris floating around means anything launched will get destroyed.

    3. Tom Paine Silver badge

      Eight downvotes for provable facts? Oh well, it IS El Reg...

  3. John Smith 19 Gold badge

    The real worry is cascade collisions, where debris from one hits a bunch of others.

    LEO is quite crowded.

    But what really surprised me is the claim only 60% of graveyard orbit burns are successful.

    That's astonishing and very surprising the figure has not been mentioned before now.

    On a lighter note is it just me that that thinks "Holger Krag" sounds like a great name for a SPECTRE assassin? Rosa Klebs half sister?

    1. allthecoolshortnamesweretaken

      Re: The real worry is cascade collisions, where debris from one hits a bunch of others.

      Um, Holgers are usually boys. But, yeah, great name.

      1. John Smith 19 Gold badge

        "Um, Holgers are usually boys. But, yeah, great name."

        And it turns out he is as well


    2. DJO Silver badge

      Re: The real worry is cascade collisions, where debris from one hits a bunch of others.

      Debris collision cascade is known as Kessler Syndrome ( and is well known to players of several space games.

    3. Anonymous Coward
      Anonymous Coward

      Re: The real worry is cascade collisions, where debris from one hits a bunch of others.

      LEO is quite crowded.

      I'd have thought that unintentional collisions were the least of anybody's worries. Looking at the loons in power all round the world, several have got either nothing to lose, or a lot less than the Americans by floating up some ball bearings and an explosive charge, and I'd wager that the technology to actively pollute LEO is easily within the grasp of Iran, Nork, Pakistan. The US have played with various types of anti-satellite missiles since the 1950s, and even had an F15 launched version successfully trialled three decades ago.

      And with a certain amount of effort, such a weapon might even be developed from a high altitude anti-aircraft missile at the sort of cost possibly within the realms of proxy war actors, some organised terrorist groups or even drug cartel funding. If you were Fat Boy Kim, what would you have to lose by polluting LEO to make life more difficult for the major powers? Or if you were the Iranians looking to make life difficult for the US, maybe offering technological help to somebody else wanting to do the deed?

    4. fishman

      Re: The real worry is cascade collisions, where debris from one hits a bunch of others.

      "But what really surprised me is the claim only 60% of graveyard orbit burns are successful."

      Probably due to keeping them up there until they stop working. And if they stop working, how can you tell it to deorbit?

      1. Orv Silver badge

        Re: The real worry is cascade collisions, where debris from one hits a bunch of others.

        Basically. If you know it's going to fail -- say, you're running low on fuel for station-keeping -- you can tell it to do the maneuver. But satellites sometimes fail suddenly, and no one wants to park a multi-million-dollar satellite that seems to have life left in it. I assume the 60% figure is for geosynchronous satellites, which are boosted into a *higher* orbit for disposal. (This is far less energy-intensive than de-orbiting them entirely.)

        As far as I know it's never been required for LEO satellites before, mostly because unlike geosync ones they will *eventually* re-enter on their own; they require periodic boosting to counter atmospheric friction. (For some value of "eventually" -- could range from months for very low orbiting birds to many thousands of years for Molniya orbits that spend most of their time well above the atmosphere.)

    5. phuzz Silver badge

      Re: The real worry is cascade collisions, where debris from one hits a bunch of others.

      "LEO is quite crowded"

      Turns out that the really-bigness of space is still unbelievable.

  4. JonW

    Time for a Levy?

    UN tax on launches (say 5% of launch cost) to fund a clean up operation. Lots of proposals out there to de-orbit junk; we just need them funded.

    I will *not* be happy if I get obliterated by someone's frozen space wee on my way to Mars.

    1. Mark 85 Silver badge

      Re: Time for a Levy?

      This presumes that UN would actually do something instead of countless speeches and parties. For the money coming in, so far not much in the way of return on investment. Perhaps a private company with "deorbit as a service"?

    2. Rol Silver badge

      Re: Time for a Levy?

      "Hi there. This is the overseer and we noticed you've just launched a satellite, but we can't find your end of life disposal insurance payment"

      "Err, what payment?"

      "End of life disposal insurance. You get a 95% refund if the satellite properly decommissions itself, otherwise we take steps to do the job"

      "You are joking. We aren't answerable to your fascist state doctrine."

      "Afraid you are Mr Tinpot. Pay up now or we decommission the thing immediately and double your premiums for future launches"

      "So, if I pay, I will get all but 5% back when my glorious scientists and engineers prove our technology will successfully de-orbit"

      "That is correct"

      "Well what about the 5%, that's not right"

      "That, I'm afraid, gets spent almost immediately, on cleaning the skies of over five beeeellion bits of crud, that were previous sent up there without the slightest consideration about pollution, and likely as not will damage your precious satellite if we don't take action"

      "Seems I have no choice then. Do you take American Express?"

  5. Chris Miller

    There is no EU Space Agency

    There is a European Space Agency (ESA), which is not an EU organisation (even though most of its members are in the EU). Canada sits on the council (? well, if Australia can take part in Eurovison ...)

  6. A K Stiles

    Dr Hugh Lewis...

    And the news? (about space junk)

    1. defiler Silver badge

      Re: Dr Hugh Lewis...

      Came here to say just that - I'm desperately glad that I'm not alone!

  7. The Bobster

    That's the Power of Love!

  8. GrumpenKraut Silver badge

    Don't let the Germans do the cleanup

    They'll never be able to decide which bit goes into which bag!

    1. Stoneshop Silver badge

      Re: Don't let the Germans do the cleanup

      Indians will get them down, then put them on a beach, have them stripped by the local population and burn wha's left.

  9. Sir Sham Cad

    Re: "How can they be better under commercial pressure"

    I thought everything was supposed to be better left to private market forces? Can I switch my Gravity Provider?

    1. Anonymous Coward
      Anonymous Coward

      Re: "How can they be better under commercial pressure"

      Can I switch my Gravity Provider?

      Yes, of course you can.

      As with gas and electricity, changing providers is easy. Your gravity supply will remain unchanged and still be accessible through the standard distribution system, the only change will be who bills you for it.

      I'd be very happy to offer you my services in this regard; please provide me with your bank details and address....

      1. Pedigree-Pete

        @ AC re: Changing Gravity suppliers.

        You were about to get an upvote for soliciting business to your alternate Gravity Supplier but posting AC makes that pretty tricky. PP

        >> but have one of these for the 1st working day of the week. (at least for much of the UK).

      2. Stoneshop Silver badge

        Re: "How can they be better under commercial pressure"

        Gravity resellers should start offering rebate schemes, like those for energy where they offer to send a solar panel to a developing country for every three or five you're installing: send one Newton of gravitational force towards de-orbiting space junk for every five you're using yourself.

  10. W4YBO

    Just a quick perusal of CelesTrak...

    3964 instances of DEB (debris large enough to be tracked), 94 R/B (rocket bodies), more than a thousand chunks of Cosmos 2251 (smacked Iridium 33) debris, and more than twice as many from Fengyun 1C (2007 Chinese ASAT test). Probably need a great big Kevlar catcher's mitt to slow any of that stuff down enough to deorbit it.

    Wow! Have cubesats ever become popular! Nearly three-hundred of 'em. It'd be tough to deorbit those little bits. Maybe incorporate a gas-charged ballute or streamers to increase drag on LEOs.

    1. bazza Silver badge

      Re: Just a quick perusal of CelesTrak...

      AFAIK cube sats are deliberately put into low orbits where they're going to burn up quite soon no matter what.

  11. Anonymous Coward
    Anonymous Coward

    In space

    Is it keep left or keep right?

    1. hplasm Silver badge
      Paris Hilton

      Re: In space

      You should stay to the Up, except when passing on the Leght- except when manoevering Topwards, in which case yaw to the Rieft.

      Down is generally bad.

      Don't forget. Speed up to slow down!

  12. jimdandy

    Re: Satellite Collisions

    Ooh! Hunter-snatcher satellites that launch multi-prong nets of rockets to take out the annoying space junk from leftover launches, then delivering them to safe sites below (or burning up in the atmosphere)!

    Or anything else someone doesn't want up there.

    Seems like a perfect reboot of Missile Command.

  13. hoola


    Just like everything else mankind does, the consequences are ignored until it is too late. The main driver behind this is profit and the strange belief that "they" will clear up the mess (at no cost). Here on earth that is the local council, etc. Up in space there is no one, and in the race to put the stuff up there (probably with not that much real benefit to the majority), the cost of disposal is ignored. By the time the satellites need to be decommissioned, the profits will have been made and the companies probably already closed down. The result that a few Western nations will end up taking most of the hit in cleaning it up.

    Nuclear Waste?

    Acid Rain?



    Electronic Waste?

    And so the list goes on

    1. imanidiot Silver badge

      Re: SIgh,,,,


      Nuclear Waste?

      Actually not all that much of a problem if people would only just get over their paranoia over what constitutes nuclear waste and reworking of used fuel bundles (yes, you get plutonium, no you can't just build a bomb out of used fuel plutonium as it'll take a LOT of processing to remove neutron poisons and then you are left with the wrong plutonium isotope.

      Acid Rain?

      Not actually as big a problem as it was first made out to be and pretty much succesfully solved by tighter regulation on emissions from factories and power plants.


      Again, tighter regulations (and bans) on use of CFCs has largely solved this issue and the latest evidence indicates the Ozone layer in the atmosphere has been recovering.


      Jup there's a problem. Not easy to solve either

      Electronic Waste?

      Shouldn't be a problem and isn't a problem in a lot of countries.

      Yes, we face a lot of problems as humanity. No, solving them won't be easy. It's not just the rich nations taking the hit for this. Every nation on this planet benefits from access to space.

  14. John Smith 19 Gold badge

    The real problem is the thousands (millions?) of pieces of space junk we can't see

    Small but high relative speeds ready to hit still working stuff in orbit.

    What's needed for this is something very low cost operating over a wide area.

    My instinct is to find some way to charge these so they feel drag from the Earth's magnetic field and spiral down and reenter.

    1. Pudders

      Re: The real problem is the thousands (millions?) of pieces of space junk we can't see

      Most (all) Satellites are going the same way, who would put up an LEO Sat going backwards (retrograde), so the relative speed of collisions is lower than you'd expect.

      If you could charge your Sat to feel the drag of Earth's magnetic field, you could also use said charge for manoeuvring, which we can't or we'd already be doing that.

      Sorry to poo-poo :-(

  15. breakfast
    Paris Hilton


    How has it got to this point without anybody making a joke about a catastrophic junk collision???

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