Re: Hubble good as dead

From: Herb Schaltegger (herb.schaltegger_at_gmail.com.invalid)
Date: 03/13/05 

Date: Sun, 13 Mar 2005 13:00:33 -0600

In article <ou%Yd.28036$5T6.11437@bignews4.bellsouth.net>,
 "Joe D." <joe@nospam.invalid> wrote:

> "Herb Schaltegger" <herb.schaltegger@gmail.com.invalid> wrote in message
> news:herb.schaltegger-AB813F.09575513032005@news.newsguy.com...
> >
> >> I'm not saying it's the most ideal location for HST, but I don't
> >> understand
> >> your total, unqualified statement that it's *absolutely* unworkable.
> >
> > Then you don't understand how messy the orbital environment of ISS
> > really is.
> >
>
> There have been various space-based telescopes physically attached to manned
> habitats. Salyut had a 1 meter diameter telescope. There are current
> plans to mount a 16 inch optical telescope on ISS:
>
> http://www.issat.org/Mission/index.htm

Plans by whom? If they're not NASA, ESA or Russian plans and fully
funded, it's just hand-waving.

And they REALLY don't understand how messy the ISS external
environment is.

> Original ISS plans included a large free flying space telescope. It was
> cancelled due to budget reasons, not because it was absolutely unworkable:
>
> http://www.astronautix.com/craft/issscope.htm

That was the MTFF - Man-Tended Free Flyer - and it was indeed
cancelled due to budgetary concerns. Part of the budgetary pressure
was how to make it close enough to be routinely "Man Tended" and still
deal effectively with contamination from its environment and such
visits. I was working on SSF when it was cancelled.
>
> I still maintain HST in the ISS orbit is workable, though not ideal. I
> assume NASA agrees, since they didn't reject the solar space tug servicing
> mission on that basis, rather on the space tug assembly difficulty.
> I would not describe HST in the ISS orbit as *absolutely* unworkable.

Any closer than many hundreds of kilometers ahead in the orbital path
will contaminate optics and solar arrays with hydrazine, water ice,
carbon dioxide ice and potentially ammonia, among many other trace
chemicals. That will play absolute hell with HST's primary mirror.
Period. No matter how *you* would choose to describe the situation. 

-- 
Herb Schaltegger, B.S., J.D., GPG Key ID: BBF6FC1C
"The loss of the American system of checks and balances is more of a security
danger than any terrorist risk." -- Bruce Schneier
<http://dischordia.blogspot.com>
<http://www.angryherb.net>

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