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NASA Space Science

New Spacecraft Set For Dangerous Jupiter Trip 159

Posted by kdawson
from the by-jove dept.
solaGratia passes along word of the equipping of Juno, the most heavily armored craft ever to be launched to another planet. The launch is scheduled for a year from now. "In a specially filtered cleanroom in Denver, where Juno is being assembled, engineers recently added a unique protective shield around its sensitive electronics. ... 'For the 15 months Juno orbits Jupiter, the spacecraft will have to withstand the equivalent of more than 100 million dental X-rays,' said... Juno's radiation control manager... [The] titanium box — about the size of an SUV's trunk — encloses Juno's command and data handling box..., power and data distribution unit..., and about 20 other electronic assemblies. The whole vault weighs about 200 kilograms (500 pounds)."
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New Spacecraft Set For Dangerous Jupiter Trip

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  • SUV's trunk... (Score:5, Insightful)

    by Wyatt Earp (1029) on Sunday August 08, 2010 @02:16AM (#33178512)

    An SUV doesn't have a trunk.

  • SUV trunks? (Score:4, Insightful)

    by Mr. Freeman (933986) on Sunday August 08, 2010 @02:44AM (#33178604)
    Has the US population degraded to the point that we can't figure out what a square meter is? Do we need to measure volume in terms of SUV trunks?

    I'll forgive people for not being familiar for units of radiation exposure because it's not something that 99% of the population will ever deal with, but how the hell does a dental x-ray put it in perspective? It's not like you can feel an X-ray. (If you can feel radiation then it's way more than enough to kill you, below insta-death levels you're not going to feel a damn thing).

    At least with the size of the thing they gave dimensions in addition to their bullshit comparison, they didn't even bother to mention with real units how much radiation this thing will have to withstand. This serves to do nothing but perpetuate the idiocy growing more and more common in the US today.
  • Dangerous to whom? (Score:2, Insightful)

    by davidwr (791652) on Sunday August 08, 2010 @02:57AM (#33178640) Homepage Journal

    I'd say any manned mission has a higher risk of fatalities than this one.

  • by St.Creed (853824) on Sunday August 08, 2010 @05:47AM (#33179104)

    Beat me to it :)

    But on a more serious note: a dental x-ray can vary between 5 and 170 micro Sievert (source: http://hps.org/hpspublications/articles/dentaldoses.html [hps.org]),
    so this could be between 500 and 17000 Sievert. A rather large uncertainty in such a statement. Not that it wouldn't be lethal, since anything over 6 Sievert (acute dosis) is considered lethal (and even 1 Sievert acute will get you radiation poisoning - see Wikipedia).

    What's with scaring people about dental X-rays, though? While I appreciate the need for an analogy, couldn't they have come up with a better analogy for this one? Like "equivalent to standing inside Chernobyl starting on the first day of the accident, for 15 months in a row"? (*)

    That'd make the picture much clearer, I'd say.

    (*) using 20 Sv for Chernobyl first day exposure (max value) and the average value for the potential exposure with the 100 million dental x-rays, which gives 8750 Sievert total exposure.

  • by kurokame (1764228) on Sunday August 08, 2010 @07:17AM (#33179308)

    Deep space is considerably lower in radiative flux than it is when you're near a star for obvious reasons involving decay times and 1/r^2 laws. If it worked like you're saying, the universe would be extremely bright and extremely hot everywhere. In real life, most of it is just empty.

    Also, there's an old trick which pops up in hard SF every now and then. Bury your interstellar ship inside layers of rock or water or both. Get it thick enough and it will shield out damn near anything which you're likely to encounter regardless of where you are or how fast you're going. Of course there are still places you're likely to want to avoid...stellar nurseries are probably not a nice place to be, nor do you want to get too far on the inside of the habitable zone of a star. Stuff like that. But the fun thing about radiation is that you can stop any conceivable level of radiative flux simply by putting enough matter between it and you. So much for "no way" eh?

    As for something as simple as sending a probe to Mars - yes, you have to account for radiation in the design. But it's hardly insurmountable. If somehow it mysteriously happens that nothing else works, you can always fall back to covering the hull in water tanks. Higher fuel cost, but certainly possible.

  • by loufoque (1400831) on Sunday August 08, 2010 @07:53AM (#33179458)

    Humans beyond LEO? Don't make me laugh! This is the Achille's Heel of any Mars mission. There is no existing technology that can fix this either.

    Just make a massive ship; its sheer mass would provide enough shielding.

    Obviously, it would have to be built in space. But to make a good enough space or moon base, you'd have to bring fairly massive amounts of material as well. And the only cost-effective ways to do that are propulsion based on nuclear explosions or a space elevator.
    One technology people are afraid of, the other is not ready.

  • by imsabbel (611519) on Sunday August 08, 2010 @10:42AM (#33180162)

    Its a meassurement with 1 significant digit. Thats a more correct way than the typicel " about 1 inch (2.54cm)" type conversion that implies a higher accuracy in one type of unit

  • Cost effective. (Score:1, Insightful)

    by Anonymous Coward on Sunday August 08, 2010 @11:51AM (#33180592)

    I think he meant that there is no COST EFFECTIVE way. There is a way to do most things (but not all) but for many things, the cost is prohibitive.

  • by Anonymous Coward on Sunday August 08, 2010 @03:21PM (#33182364)

    Humans beyond LEO?

    well shit, I bet you're the type who thinks the various moon missions were fake as well.

    The moon is beyond LEO.

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