Re: [ATM] The Hubble mirror goof up.

[Jim Burrows <burrjaw@earthlink.net>]

At 2005-03-07 20:19 -0500, Mark Holm wrote:

>The second nuller might not have been as precise, but it surely would have 
>shown the gross 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.

According to Bob Goff, Perkin Elmer ran three final tests on the Hubble 
primary:  reflective null, refractive null, and good ol' Foucault (the 
military had a big enough flat for an end-to-end test, but it wasn't 
available in time).  It was 2 to 1 that it wasn't done: refractive and 
Foucault vs. reflective.  The managers said the reflective null tester was 
more than twice as accurate as the other two, so chuck it up into orbit for 
the final star test <g>.  Bob said all the guys that knew anything had quit 
or retired because Congress' chintzy funding had dragged the program on too 
long.

         -- Jim Burrows
         -- mailto://burrjaw@earthlink.net
         -- http://home.earthlink.net/~burrjaw
         -- Seattle N47.4723 W122.3662 (WGS84) 

_______________________________________________
ATM mailing list http://www.atmlist.net/