[R-390] TUBES

Fri, 22 Feb 2002 09:15:20 -0800

Fellows,

I was whining about the paint job on some panels at an old
Aircraft Plant in Fullerton California. I meet the guy that put the
paint job on a moon buggy. The kids under him still could not
get a paint job on a rack panel with out runs. Blamed it on
Cal OSHA paint.

Any way the old Hughes story is that in the mirror grinding process,
the boys when to far. The solution was to shim up one corner of the
mirror and polish that down to spec. As opposed to scraping the
whole thing.

You can not just use any thing for a shim. You needed an exact
shim and you needed a engineering drawing note to get the
exact shim installed in the correct corner.

The shim was made (selected). The engineering note was make.
The shim was installed and the polish was completed.
Then the whole thing went into storage for a long time.
(awaiting a launch ride)

So when they got the Hubbell out of storage to go for the ride,
Some one thought that it needed an inspection. Never mine
we will never look through the telescope to see if it works,
but we will jiggle all the bolts nuts and screws.

Some one took the shim out. Why is this corner different?
Some one lost the shim.
Some one found out.
Some one pointed to the drawing and said put it back.
Some one could not find the shim
Some one said make another one just like it.
Some one got close oops.
They installed it.
Never looked through the scope
It was not as expected.
Some decided it would be easier for a guy in a space suit
to change almost every thing except the shim to fix the problem.
Some said lets bring it home and look at it.
The bean counting insurance fellows said no way in hell
will we do any thing that may inflict liability on any one.

Now, did the guys mess up the mirror and then mess up
the shim fix. Or did some thing else get assembled wrong?

Roger.

                    [email protected]                                                                                  
                    e.vt.us (Todd            To:     Ed Zeranski <[email protected]>                               
                    Bigelow - PS)            cc:     mikea <[email protected]>, [email protected]                 
                    Sent by:                 Subject:     Re: [R-390] TUBES                                            
                    r-390-admin@mailm                                                                                  
                    an.qth.net                                                                                         

                    02/22/2002 07:32                                                                                   
                    AM                                                                                                 
                    Please respond to                                                                                  
                    tbigelow                                                                                           

I had heard that the calculation involved was one that did not take into
account
just how the mirror would sit once it was outside of earth's gravity.
Someone
should've made a scale model and taken it for a test ride in the
VomitComet...

Boomer

Ed Zeranski wrote:

> >The Hubble bobble had nothing to do with miscalculation, though:
> >it was caused by a tech at (IIRC) Perkin-Elmer putting a gauge
> >stick in bass-ackwards, so that the mirror's focal length was
> >off.
>
> Not a normal miss calq of numbers, you are right, but still a miscalq of
> risk. Have you read the after event stuff by Richard Fineman?  The old
gnome
> got dismissed as 'just a CALTECH physicist' when he said the board wasn't
> even asking the right questions. :^)
>
> Can't troubleshoot if you won't admit there is a problem.

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