Re: Apollo 1/204 Service Module RCS quad access panels Was: Pyro Relays vs. Isolation Valves

From: rk (stellare_at_NOSPAMPLEASE.erols.com)
Date: 07/05/04 

Date: 05 Jul 2004 11:24:45 GMT

Charleston wrote:

> <hpywife927@yahoo.com> wrote:

           [ Snip Discussion of panels with picture references ]

It is interesting [and to work in a bit of actual space history and
engineering] to note that the mechanical design of the panels implemented
lessons learned from previous manned missions.

   The quad concept employed on the SM is an advanced stage of
   modularization and has simplified manufacturing, checkout, and
   servicing as well as the replacement of components. In Project
   Mercury, it was difficult to replace even a single valve on the
   RCS. On the SM, the entire panel is removed and replaced with a
   spare panel. The panel requiring replacement of a component is
   returned to the factory for repair. With this approach, the SM
   RCS can be completely manufactured and check out independently
   of the other subsystems.

   Source:

   "Apollo Reaction Control Systems"
   Chester A. Vaughan, Manned Spacecraft Center, Houston Texas
   Paper No. 68-566
   AIAA 4th Propulsion Joint Specialist Conference
   Cleveland, Ohio

                   [ snip ]

> scroll down to witness statements, select your
> favorite format, and search on "quad".
>
> WILLIAM J. SCHNEIDER
>
> "At this time, I saw the fire; and there was fire inside the Service
> Module or it appeared to be inside the Service Module. I could see it
> through the open doors - the open quad doors. Someone at this time
> hollered that we had to get the fire out or else the LES would go; and
> another man and myself, Space-craft inspector, got a fire extinguisher
> and started playing it inside the door of the Service Module. When this
> fire extinguisher ran out, I left Level 7, took the stairs down to Level
> 6 and got another fire extinguisher on Level 6, came back up to Level 7
> and by this time, the fire seemed to be in pretty good control on Level
> 7."

Note that the Project Manager for Skylab was William C. Schneider; this is
William J.

>> There are a lot of factors
>> involved in where a fire will travel once lit.
>> HOWEVER, there is more than one witness statement that talks about a
>> cable being on fire--remember, Daniel?
>
> *if you were inside the Command Module at
> the time of the fire when the pressure vessel failed,
> it would be roughly equivalent to being inside
> an automobile tire blowout as far as air pressure
> changes go. This would not be good for small and delicate
> blood vessels in your lungs. Nor would it be nice for family
> members to hear about pulmonary compression,
> rapid pulmonary decompression, pulmonary hemorrhagic
> edema, cyanide gas at fatal levels, all on top of the fact
> that your loved one suffered through a horrible toxic fire.
>
> Daniel
> Thank God I am off work today.

It is, of course, not nice for anyone to hear and on this weekend (USA
context) it's a good reminder [better word?] to treat the death of those who
sacrificied, and their survivors, with proper respect. 

-- 
rk, Just an OldEngineer
"Dealing properly with very rare events is one of the attributes that 
distinguishes a design that is fit for safety-critical systems from one that 
is not."  -- John Rushby in "A Comparison of Bus Architectures for Safety-
Critical Embedded Systems," March 2003

Relevant Pages

  • Re: Need for pool
    ... system as being appropriate for fire alarm until it received the UL listing. ... I recommend System Sensor smokes for all Honeywell panels. ... Until the PANEL MANUFACTURER does, there's no way anyone in their right mind would accept the installation. ...
    (alt.security.alarms)
  • Re: FCI 7100
    ... > Insist they replace the fire alarm control panel. ... >> system installed by a reputable fire alarm contractor. ...
    (alt.security.alarms)
  • Re: Notifier AFB-200
    ... >>> how to return the PASSWORDS to default on the panel. ... >>> you think it's necessary to yell FIRE when discussing the panel? ... > fire alarm systems you would have known that. ...
    (alt.security.alarms)
  • Re: FCI 7100
    ... Your fire panel should be testing BOTH telco lines at least every 24 hours. ... If one of them fails it should display a comm fail or trouble - it's ... > system installed by a reputable fire alarm contractor. ...
    (alt.security.alarms)
  • Re: Apollo 1/204 Service Module RCS quad access panels Was: Pyro Relays vs. Isolation Valves
    ... >> the sector door was open! ... > I did not design the Service Module. ... > SM RCS quad assembly access panel including the ... > the fire would have gone from the simulators to the ...
    (sci.space.history)