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NASA Space Science

NASA To Cryogenically Freeze Satellite Mirrors 47

coondoggie writes "NASA said it will soon move some of the larger (46 lb) mirror segments of its future James Webb Space Telescope into a cryogenic test facility that will freeze the mirrors to -414 degrees Fahrenheit (~25 K). Specifically, NASA will freeze six of the 18 Webb telescope mirror segments at the X-ray and Cryogenic Facility, or XRCF, at NASA's Marshall Space Flight Center in Huntsville, Alabama, in a test to ensure the critical mirrors can withstand the extreme space environments. All 18 segments will eventually be tested at the site. The test chamber takes approximately five days to cool a mirror segment to cryogenic temperatures."
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NASA To Cryogenically Freeze Satellite Mirrors

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  • by Anonymous Coward on Saturday January 09, 2010 @11:52AM (#30707566)

    Physics is one of many fields where the more you study the closer you come to reality: you use more primitive models when you begin your study and each year after that you learn that the model you learned last is an approximation of something else. Perhaps it's a fitting way to learn, given that it's how the field develops, or perhaps it isn't, but please don't tell people to STFU because they're wrong; what they know may be a far better approximation of the truth than what most people know, and we want people with a less thorough background to feel comfortable talking in their communities about what they've learned, even if it's a model a professor short-on-time gave them to understand a concept. A pound of honey, as they say--if we insult everyone who doesn't know everything about physics but decides to talk about it, soon almost nobody will talk about physics. And not many people talk about it today.

  • Re:Cryo! (Score:5, Insightful)

    by TapeCutter ( 624760 ) * on Sunday January 10, 2010 @02:03AM (#30712884) Journal
    "Are you saying that it isn't just to formally revenge the victim?"

    The answer depends on how you define [wikipedia.org] Justice [wikipedia.org], I would define the implementation of justice as an act that restores, or adequately compensates for, what the victim has lost. Some deeds simply can't be undone or justly compensated for. Other than the poetic kind (and using my #def) there is no possible justice for the murder victim, although blood money may compensate the relatives for the loss of the victims material input, it does nothing for the victim.

    The overused Gahndi quote sums it up best "an eye for an eye makes the whole world blind". The victim and the murderer are both dead and (unless you believe in hell), are no longer suffering. The outcome for those still alive after the execution is a doubling of the number of families that are suffering a loss.

    Since murder can't be undone the question then becomes one of can we do anything to the murderer to deter other would-be murderers, such as publicly hang, draw and quater him [wikipedia.org] followed by prominently displaying the butchered corpse at various public places? It's a logical idea that appeals to our base emotions but real world experience says it doesn't work as a deterent even for less passionate crimes such as drug smuggling.

    "Of course given that the real murderer is executed, that he got a fair trial, that the murder wasn't an accident etc"

    In the same manner that you can defeat terrorists without using their methods, you can punish murderers without killing them. Personally I think the state should set the example of - we only kill in self defence or defence of the innocent in mortal danger, but it's "you're country - you're rules".

    None of the above means I think that murders don't deserve a bullet to the head but what we are given is the track record of the state/church/lynch-mob, It says that there is a very significant risk of inadvertently commiting the irreversible act you're trying to deter. IMHO and the opinion of the clear majority of nation states [amnesty.org], it's an unacceptable risk.

    I don't see the US joining the rest of the world in this "enlightened" view of capital punishment any time soon. A poll of SCOTUS a few years ago found that a majority of the SC Judges thought that shooting an unarmed fleeing thief was justifyable.

"How many teamsters does it take to screw in a light bulb?" "FIFTEEN!! YOU GOT A PROBLEM WITH THAT?"