Russell McMahon wrote, in part:
>[About using phase change for heat storage]
>The original nightstores used wax as an energy storage medium. This did
>have
>a phase change (the wax melted during heating) so had very good capacity.

Another example of the same principle was the cooling system used
on the Apollo Lunar Rover's communication relay electronics. Wax
was allowed to melt during operation on EVAs, thus absorbing heat.
Between EVAs (while the crew rested in the LM), mirrors were used
to provide shade, and the wax would radiate its heat and resolidify.
This worked well over the course of three missions (Apollos 15, 16,
and 17), with three seven-hour EVAs each.

To bring this posting just a little closer to topic, imagine how
PICs could be used on a modern lunar mission. The Apollo command
module and lunar module computers were considerably less powerful
than a 16F877, I think (I haven't done a point-by-point comparison,
but if I do I'll report back).

Michael V

Thank you for reading my little posting.


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