back to article Did dicky power supply silence climate-change probe Envisat?

The European Space Agency has all but given up hope of contacting its long-lived Envisat mission, a month after the satellite went silent. Artist's impression of Envisat Artist's impression of Envisat. Credit: ESA Communication with the environment-watching craft suddenly halted on 8 April. Engineers tried to regain …

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  1. Caff

    recycle

    With a fair few defunct satilites and the growing heap of space garbage I wonder would a recycle and repurposing centre be of any use up there? Start off simply refueling old sats and then move onto collecting other bits and bobs of end of use kit to repurpose?

    1. JimC

      Re: recycle

      I dunno, "up there" is an awfully big place isn't it? What's the area (never mind volume" of say the geosynchronous orbit space compared to the area of the planet? Can't be bothered to so the sums, but I suspect its a great deal of, well, space to go hunting the junk in. Bigger project than roaming the streets with the nag crying "any old iron"...

      1. AndrueC Silver badge
        Thumb Up

        Re: recycle

        >Bigger project than roaming the streets with the nag crying "any old iron".

        http://en.wikipedia.org/wiki/Salvage_1

      2. ozonehole

        Re: recycle

        Actually, geosynchronous orbit would probably not be where you'd want to put a climate data gathering satellite. Much more useful would be a polar orbit. That way you'd eventually be able to gather data on the entire surface of the earth. For communications satellites, of course, it's quite the opposite.

    2. Ru
      Boffin

      Re: recycle

      If we assume the cost of building, launching and running your average new sattelite is going to be in the same ballpark as building, launching and running a repair and refuel spacecraft (which is a generous assumption) there are still two big arguments against it:

      1. Trying to dock with a defunct sattelite risks both the sattelite and the repair craft, and an accident produces huge clouds of debris which will endanger other spacecraft for many years to come.

      2. A new sattelite is likely to use significantly fancier technology than its n-year old predecessor, and will therefore be rather more useful.

      With that sort of risk/reward tradeoff, I don't see anyone running repair missions any time soon, not until we've managed another generation or two of ever cheaper launch vehicles at the very least.

    3. Lee Dowling Silver badge

      Re: recycle

      1) You can't capture a lot of this stuff. That's why we plan to de-orbit it before its even launched. The speeds involved don't bear thinking about (one screw in orbit can tear through the Mir Space Station like it was butter - how so you capture that?) You'll notice that it's incredibly rare that we ever dock with a satellite or other orbiting thing unless both are fully-working and we can use both their propulsions and PLAN IT METICULOUSLY. One wrong move and you kill yourself, de-orbit the satellite or add to the space junk ten-fold.

      2) There's no value in them. Their biggest cost is launch, yes, but the actual satellites would cost hundreds of times more to capture and even more to repair than just binning them an launching another. Again, this is why we just de-orbit things into the atmosphere and let them burn up.

      3) "Refuelling"? Seriously? Most of the "fuel" is either highly radioactive in the old ones, or solar in the new ones. The power isn't the problem. It's the cutouts, safeties, orientation to the Sun, etc. that kills off a satellites power, not it running out of juice. The Voyager spacecraft are still running at something like 50% power while on the outside the solar system 40 years after launch.

      4) Who owns that stuff? Who will fund you to repair that stuff (much cheaper to just launch newer kit)? What if you touch a Chinese satellite by mistake? You could seriously start a war by just touching someone else's satellite, even by mistake, or causing debris from your operation to interfere with their kit.

      5) Where would you repair it? In space? Via a spacewalk? The single-most-expensive venture that one man ever performs? You know the greatest risk while you're on a spacewalk? Getting hit by space junk that's so small and fast we can't track it. Are we repairing random bits of kit that were fabbed in semiconductor labs with the latest technology from inside an astronaut's spacesuit? Or would you take it to an in-orbit space station that would cost more to build and operate than it would ever cost to relaunch all those satellites put together? Or would you bring it back through our atmosphere at huge expense and risk only to be told that the technology was obsolete and that if they were going to have to launch it again, they'd rather do it with a new model or one that hadn't already broken once?

      There's a reason all that space junk is called junk. It effectively is, because of the content, accessibility, and cost of going near it. It's like saying that 80% of the world's gold is in the ocean. It is. It will be. Until we work out a cheap way to drain and search the entire ocean for less than the difference between the total price of all gold on land and the total price of all gold in the sea.

      The safest thing to do with space junk, even with politics and cost aside, is to push it into our atmosphere. But only to get it out of the way so the next launch doesn't hit it.

      1. Tom 13

        Re: recycle

        You forgot one: Either a government or private entity still owns it, and if you solve the technical problems of capturing it in orbit, and recovered it, you'd likely be told to turn it back over to the owner with no reimbursement for your troubles. Sort of like the guy who found that wreck a couple years back and then lost it all to Spain.

      2. dajames
        Boffin

        Re: recycle

        '3) "Refuelling"? Seriously? Most of the "fuel" is either highly radioactive in the old ones, or solar in the new ones.'

        Orbital satellites do indeed use solar panels to generate electricity -- and deep space probes use radioactive sources -- but that's not the sort of "fuel" being discussed. Orbital satellites occasionally need to be moved, or to have their orbits adjusted. For that they need good old-fashioned chemical rockets and a supply of rocket 'fuel' ... which is both an energy source and reaction mass.

    4. Yet Another Anonymous coward Silver badge

      Re: recycle

      But if you put the recycled satellite in the wrong blue box the galactic space council can get very nasty.

      1. Glen 1
        Alien

        Re: recycle

        the owner of said blue box might not be best pleased either...

        Alien because the Doctor is one.

  2. Anonymous Coward
    Anonymous Coward

    Last of its kind

    Envisat was a difficult beast to get launched and the sort of monolithic mission that ESA now tries to avoid -- lose the satellite, lose a _lot_ of measurements.

    Recent missions, e.g. SMOS etc, are much more focused and generally cheaper and easier to get into operation. However this has hit the demand for Ariane V launches because its target market is Envisat-sized spacecraft.

  3. laird cummings

    Golden BB..?

    Surprised not to see speculation on the possiblity of a debris strike among the list of possible culprits.

    1. Steve Evans

      Re: Golden BB..?

      Maybe the regulator was hit by an escaped super-fast neutrino from Cern?

      Is that better?

      1. laird cummings
        Trollface

        Re: Golden BB..?

        "Is that better?"

        Much, thank you.

  4. Remy Redert
    Stop

    @Lee Dowling

    Let me correct you on a few points, since you seem to have failed physics and/or orbital mechanics.

    1) Capturing junk satellites and other debris is relatively easy. Yes, it's moving around at many kilometers per second but SO ARE YOU. Match orbits and you can just grab the debris while it's at nearly 0 relative velocity. If you know where the debris is and have the delta V to reach it, retrieval is trivially easy.

    3) Fuel in this case is the wrong word. The one you're actually looking for is 'reaction mass'. You see, many of these satellites have to expend small amounts of reaction mass from time to time, for station keeping and avoiding collisions with one another. If you can refill that reaction mass you can significantly extend the useful life of a satellite. Of course satellites aren't designed to be refillable so... Good luck with that.

  5. Gareth Jones 2
    Coat

    "after the satellite went silent"

    Actually, it's been screaming for a month - just nobody can hear it...

    ... OK, I'm going

  6. ForthIsNotDead
    Joke

    Maybe it's a sleeping satellite?

    You know, Tasmin Archer style?

    Did we fly to the moon too soon?

    Did we squander the chance? In the rush of the race

    The reason we chase is lost in romance

    And still we try to justify the waste

    For a taste of man's greatest adventure

    I blame you for the moonlit sky

    And the dream that died with the Eagle's flight

    I blame you for the moonlit nights

    When I wonder why are the seas still dry?

    Don't blame this sleeping satellite

    (I'll get me coat)

  7. Brezhnev's Shadow
    Alien

    You Izz Optional

    Who is this Dicky Power that you speak of, puny Earthling?

    1. itzman
      Black Helicopters

      Re: You Izz Optional

      A close relative of Austin.

      Anyway we know it was sabotaged by the renewable lobby when its data set looked like it was proving there was no global warming and indeed never had been.

  8. Stevie

    Bah!

    If only there were someone nearby who could give the bloody thing a tap with a Brummie screwdriver and get it going again.

    People in space, robots in car factories. A recipe for progress.

  9. Chemist

    I think you'll find that..

    it was hit by a meteoroid in just the part of its structure where the impact detection equipment was located ( or something similar)

    Cheers Douglas

  10. Anonymous Coward
    Anonymous Coward

    European space agency

    It turns out it may have been a mistake to rely on a common power supply.

    1. laird cummings

      Re: European space agency

      Be fair - it's lasted twice the warranty period. You don't normally get service like that, these days.

  11. Simon2
    Boffin

    Maybe the reason it died was because of bad capacitors in the power supply circuit which in turn resulted in fried semiconductor(s). http://www.badcaps.net/pages.php?vid=4 Just my 3p.

  12. phuzz Silver badge
    Thumb Up

    All these comments, and no-one pointing out what a clever little satellite it was for 'living' twice it's allotted lifespan.

    Who's a brave likkle satellite eh?

    (also: http://xkcd.com/695/)

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