Re: The RCS: Voice Transcript

From: rk (stellare_at_NOSPAMPLEASE.erols.com)
Date: 06/14/04 

Date: 14 Jun 2004 11:45:30 GMT

Charleston wrote:

> "LaDonna Wyss" <hpywife927@yahoo.com> wrote:

> If I can provide a "verifiable reference" to my assertion that indeed the
> Spacecraft was hooked up to simulators for both the Command and Service
> Module's, Reaction Control Systems for the "Plugs Out" test would you
> reconsider your entire explanation as to how the Apollo 1 fire really
> started? Please?
>
> http://www.challengerdisaster.info/Apollo%201%20GSE%20Config%20Drawing%20T
> -10%20Hold.jpg
>
> and then read this again.
>
> http://www.challengerdisaster.info/Apollo%201-204%20Accident%20Report%20pa
> ges%201132-1151.doc
>
> and there is more. I never would have posted the "Hill report" on my
> website if I had not read a whole lot of the Apollo 204 House Report
> first.

LaDonna:

And I shall continue to ask for the drawings, currents, voltages,
temperatures, etc.

"Apollo 1 GSE Config Drawing T-10 Hold.jpeg" shows the connections calling out
S/C boxes, part numbers, cable numbers, connector reference designators, etc.
All of the standard type of material that you would expect in such a document.
It also includes a cartoon drawing of the inside of the simulator, without
component part numbers or values for the CM simulation -- see detail 2. For
the SM simulation, see detail 3, it's similar (-21 instead of a -11), and
since you are the expert you can explain the difference.

The drawing that Daniel provided constitutes a verifiable reference, I can go
to the library and get it, the document is signed by the authors, and for
additional detail I can pull cable drawings, simulator drawings, flight
hardware drawings, etc. Also, for the documented state of the spacecraft, the
QA and test logs can be reviewed as typically the mating of connectors will be
a specific step in a procedure and be witnessed and verified by QA, who should
have a spot to sign, initial, and/or put their stamp on the document. There
also may be photos of the installation. I would expect there to be, I have
not searched for it yet. There may be pre-fire pictures as often photographic
records are taken to document configuration. I would expect to find
photographic records post-fire as part of the investigation. Since you are
the investigator here, you should be able to find photographic records
documenting what you feel is the configuration of the spacecraft.

Now you previously claimed:

     Back to the SM thrusters: we have pinpointed the source of the fire
     to the wiring in the heater of one of the thrusters. It is not
     necessary for the pin of the thruster to actually move in order to
     keep the heater hot until it burns; all that is necessary is sustained
     electrical power to the thermo switch,

I would like you to produce the following:

   * Exactly what wires. Identify the cable and the connector/pin number.
   * Show how the signals were sent to the thrusters by wiring diagram
     and configuration (see above). Daniel has shown some good drawings.
     If you think that "the wire" went through some other connector that
     is not shown on this diagram then by providing the circuits (which
     has been asked for) this can be reviewed.
   * List of elements in the circuit, currents, voltages (then we can
     compute power in the element). This should be the nominal expected
     currents and voltages and those from telemetry, since if things were
     heating up as you expect changes to the nominal values should be
     observable.
   * Complete source of power to this circuit including impedances such as
     the cable and power source along with a description of where current
     and voltage monitoring was performed in these circuits and telemetry
     values.
   * Description of where all temperature sensors are located and their
     values from telemetry.
   * The results of tests on the mockups of these circuits, circuit
     simulations, and/or analysis. I would expect for an investigation of
     this sort that all three would be readily available.

These are rather basic questions. Then we'll get into the details.

I still do not concur with your assertion that a "hard short" at the S11
switch will have zero impedance and that potentially infinite current can flow
through it. What is the wire gauge, type, and insultion for that wire and
what are the worst-case currents that could flow through it, assuming a "dead
short?" 

-- 
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

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