Re: ISS vs Skylab

From: Derek Lyons (fairwater_at_gmail.com)
Date: 12/10/04 

Date: Fri, 10 Dec 2004 00:07:51 GMT

Herb Schaltegger <herb.schaltegger@gmail.com.invalid> wrote:

>In article <41beaa9d.4576451@supernews.seanet.com>,
> fairwater@gmail.com (Derek Lyons) wrote:
>
>> Though how much of the systems were properly built for maintenance
>> is a question.
>
>In the U.S. side of things, all of it, to some degree. All
>mission-critical and module-critical electrical, electronic and
>mechanical hardware (including individual valves, connectors and
>couplings) were/are specified to allow for on-orbit replacement, even
>inside standoffs and endcones.

Pardon me if that doesn't give me a warm fuzzy. [1] 'Being able to
maintain' and 'designing to be maintained' are two somewhat different
statements. Much of the equipment onboard the boat could be
maintained without a shipyard, yet still required removing
interference [2] before the component could be moved for maintenance
(preventative or corrective) to be performed. Some voyage repairs we
were theoretically capable of performing simply couldn't be done
practically without tender assistance.

Designing for maintenance means being able to get at things, and move
them about. It means providing for isolation and bypasses. It means
proper spares, tools, stowage, etc..

The Navy is now building it's fourth generation of submarine actually
designed for maintenance, and the I get the feeling from folks I've
talked to that they're just now starting to get it right after thirty
years of trying and extensive field experience. [3]

>NASA-STD-3000 was the Bible.

I'd be interested in seeing a copy, or at least a good description of
the contents and general standards.

D.

[1] No insult meant, intended, etc. I've dealt with these issues in
the field, and what an engineer thinks or a specification says and how
things actually work can be somewhat divergent I've found through
bitter experience. How much my experience can fruitfully be compared
to ISS is a matter open to question and large grains of salt.

[2] Removing piping, cabling, etc... that belongs to other
systems/components, as opposed to breaking the interfaces to the
component being maintained.

[3] One of the best moves they made was getting the lower level
enlisted involved in the current generation... The guys who actually
do the work, as opposed to the enlisted managers that characterized
the earlier efforts.

D. 

-- 
Touch-twice life. Eat. Drink. Laugh.
-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL

Relevant Pages

  • Re: ISS vs Skylab
    ... Herb Schaltegger wrote: ... >> Though how much of the systems were properly built for maintenance is ... NASA has repeatedly made the mistake of assuming that certain subsystems ...
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  • Re: ISS vs Skylab
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