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Old 13-02-2020, 04:53 PM
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multiweb (Marc)
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Join Date: Oct 2007
Location: Sydney
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Quote:
Originally Posted by gary View Post
Each mirror has 36 hexagonal segments and the surface shape of
a segment depends on its distance from the center. It turns out that there
are six different surface shapes.
Oh wow. Is the whole telescope design a Ritchey Chrétien or other? Must be a manufacturing nightmare. How do they independantly test segments that have those "exotic" asymetric shapes I imagine yet focus each area of light to the same point? Do they use some kind of scafold in the factory with the elements in their respective position from the optical axis for figuring and testing?

Quote:
Originally Posted by gary View Post
So they carry spares which they can swap-out during re-aluminizing.
Each segment is 1.8m across and as you mentioned it is a lot easier to
handle something of that size compared to the logistics of each time they
re-aluminize the 3.8m AAT.
1.8m? Those trolleys didn't look that big in your photo, it was hard to have a sense of scale but they're massive on their own.
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