Hubble Servicing Mission #4 |
Hubble Servicing Mission #4 |
Jun 13 2008, 06:47 AM
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The Poet Dude Group: Moderator Posts: 5551 Joined: 15-March 04 From: Kendal, Cumbria, UK Member No.: 60 |
You HAVE to go look at this new video... the hairs on your neck will literally stand up.
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Jul 14 2008, 06:33 AM
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Member Group: Members Posts: 191 Joined: 20-November 06 From: Saint Louis Member No.: 1376 |
I doubt any part of Hubble will survive re-entry. Maybe some small charred bits here and there, but Hubble's re-entry will be targeted over ocean, so those tiny bits will surely be lost to the sea. There's a vast difference between a Mercury capsule and Hubble.
Thinking about all this did remind me of the biggest constraint towards any shuttle mission to Hubble. In fact, it's the one thing that has made this current mission so difficult; the lack of "safe haven" on the ISS if there was any significant damage to the shuttle during launch. STS-125 is essentially a two-shuttle mission. Atlantis will launch to Hubble, and meanwhile Endeavour will be poised on the other pad just in case a rescue mission is needed. So any Hubble mission needs two tanks, four boosters and two fully processed shuttles to pull it off. Though it's sad not to have the telescope itself on the ground, the photographic and scientific catalogue Hubble has compiled will last for many many generations. So even without the telescope physically present, its legacy will long be remembered. (We still have many more years of observations to make with Hubble, so let's not get ahead of ourselves. ) -------------------- - Matt
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Jul 14 2008, 07:34 AM
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#3
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Director of Galilean Photography Group: Members Posts: 896 Joined: 15-July 04 From: Austin, TX Member No.: 93 |
There's a vast difference between a Mercury capsule and Hubble. Of course! I don't expect a shiny, pristine 2.4m mirror to be scooped off the bottom of the ocean by Alvin, but I'm optimistic considering the large chunks of skylab (that was forced into a tumbling reentry) found after its demise. Considering Hubble weighs 24,500 lbs, most of which is behind the mirror (1,800 lbs itself), chances have got to be high that significant pieces survive. Piece of the mirror, or just part of a fuel tank, if somebody does recover part of Hubble, I would pay to see it. Just on a lark, I tried calculating a rough estimate of the mirror's density: 2.4m^2*3.14159-.6m^2*3.14159 = 16.9m^2 area The thickness I get from http://www.scienceclarified.com/scitech/Te...pes/Hubble.html as 12" or .305m So a volume of 5.15m^3 for the mirror. Plugging in the weight of 828kg gives a density of 160kg/m^3, or about 15% of (pure) water's density! A 100% intact mirror could bouy 5,000+kg on its own. That, or my math is totally broken. Can anyone spot the mistake? I'm assuming the mirror's honeycomb cells are sealed based on the above reference that states 1.5" of solid glass plate were sealed to the front and back, and abraded to 1". -------------------- Space Enthusiast Richard Hendricks
-- "The engineers, as usual, made a tremendous fuss. Again as usual, they did the job in half the time they had dismissed as being absolutely impossible." --Rescue Party, Arthur C Clarke Mother Nature is the final inspector of all quality. |
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