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Astronauts Begin Final Spacewalk To Repair Hubble

Posted by CmdrTaco on from the wave-while-you're-up-there dept.

An anonymous reader writes "Astronauts John Grunsfield and Andrew Feustel began the fifth and final spacewalk of their Hubble Space Telescope repair mission this morning at 8:20AM. During their spacewalk the two will install the second battery group replacement in an equipment bay above the Wide Field Camera 2 and next to the compartment where the first battery set was installed on the second spacewalk. Each of the battery module weighs 460 pounds and contains three batteries. The batteries provide electrical power to support Hubble's operations during the night when there's no sun to power the solar arrays."

13 of 94 comments (clear)

  1. The batteries weigh what? by Sockatume · · Score: 5, Interesting

    I'm willing to bet that the batteries don't weigh anything right now. ;) Of course using "mass" as a verb is just taking the piss, so I won't do that. I'm sure someone will.

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    No kidding!!! What do you say at this point?
    1. Re:The batteries weigh what? by Jamamala · · Score: 5, Informative

      According to my back-of-an-envelope calculations, I get their true weight to be 1729N.

      F=GMmr^-2
      =G * Mass of earth * mass of box * (Earth's radius + Hubble orbit height)^-2
      =(6.67x10^-11 * 5.9742x10^24 * 208.7) * ((6378 + 559)x10^3)^-2
      =1729.20 N

    2. Re:The batteries weigh what? by blueg3 · · Score: 4, Informative

      Pound-mass or slug, your choice.

    3. Re:The batteries weigh what? by vlm · · Score: 4, Informative

      Um, it's the pound. Doesn't everyone know that? 2.2 lbs to the kilo.

      While weight certainly means the force created between two masses due to gravity, it is almost always used interchangeably with mass in practice.

      Still messed up. Trying to compare a metric unit of mass to a imperial unit of weight using a conversion factor that only works at roughly sea level on earth.

      Metric unit of weight - Newton N
      Metric unit of mass - Gram g

      Imperial unit of weight - Pound lb (you know, like Pound Sterling being a pound of silver?)
      Imperial unit of mass - Slugs

      --
      "Science flies us to the moon. Religion flies us into buildings." - Victor Stenger
    4. Re:The batteries weigh what? by Maddog+Batty · · Score: 4, Insightful

      Only true if the HST + shuttle were stationary and balanced on a very tall table rather than being in orbit. As they are actually in free fall, effective gravity is zero and hence the weight is zero too.

      (Yes I do understand that gravity is acting on the HST + shuttle to keep it in orbit but there is no force required to support them which is the definition of weight)

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      wot no sig
    5. Re:The batteries weigh what? by jmn2519 · · Score: 4, Funny

      African or European?

  2. Watch it live by Audiophyle · · Score: 5, Informative

    Check it out on NASA TV if you haven't had the chance yet. Viewing Hubble the way the astronauts see it is a neat experience.

  3. Not above the WFC2 by Zpin · · Score: 5, Informative

    It's actually Wide Field Camera 3 now. It has been exchanged in the first spacewalk.

  4. Astronaut helmet cams by 192939495969798999 · · Score: 4, Insightful

    Let me just say, thanks NASA for the astronaut helmet cams! That footage lets me live out my astronaut fantasies without all the space-induced nausea and military training.

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    stuff |
    1. Re:Astronaut helmet cams by Paperweight · · Score: 5, Funny

      That's the only thing holding you back?

  5. First tweets from space by alen · · Score: 4, Informative

    http://twitter.com/Astro_Mike

    one of the astronauts is live blogging on twitter from the shuttle

  6. Comment removed by account_deleted · · Score: 5, Funny

    Comment removed based on user account deletion

  7. Re:Proof... by Maddog+Batty · · Score: 4, Informative

    Technically the batteries have the same mass while on Earth as they do while orbiting it. The weight in orbit is zero. (which is the point the above are making)

    See here: http://en.wikipedia.org/wiki/Mass_versus_weight

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    wot no sig