Re: [ATM] The Hubble mirror goof up.

[Michael Peck <mpeck1@ix.netcom.com>]

At 07:19 PM 3/7/2005, Mark Holm wrote:
>I remember there was a rather detailed and complete analysis of the error 
>presented in a Sky and Telescope article.  From reading that several years 
>ago, I do remember it seems the big screw up was not doing a sanity check 
>by another method.

My recollection is that both reflective and refractive Offner null tests 
were performed. The reflective null was supposed to be more accurate.


>error introduced by the bad spacing in the primary nuller.  Many have 
>said, I do not know if it is true, that the error could also have been 
>detected by a zonal Foucault test.
>

Well, maybe in theory. The actual error was about 1% in conic constant, 
which is way beyond the limits of most ATM's precision. It's a huge myth 
that the error could have been detected just by eyeballing knife edge shadows.

Mike Peck


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Michael Peck
mpeck1@ix.netcom.com

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