Well, after much thought I went to this website. Boy was it bad. Some thoughts on the "extreme thermal cycling"

I don't know if I would agree with Jay when he states "The case for such cycling is based on a very naive thermal model." I think he's being too nice. To achieve the results that Brad Guth claims his thermal model would need to have no mass, no conduction to (or from) anything, no thermal radiation to (or from) anything, absorb the same amount of solar energy as the lunar surface and emit the same amount of infrared energy as the lunar surface. I wouldn't even call these poor assumptions. This is, I need an answer, so I'll make assumptions which will give me the answer I need. One might as well just use a print statement.

On to thermal control systems. I would say that Jay is correct in stating that the landings occurred during the day at least in large part for thermal control system considerations. Once the sun stops shinning the temperature of the surface drops off quickly to -155°C (-247°F) and stays that way for the entire lunar night. At least during the lunar day, the temperature increases slowly and predictably. In the early 1990's NASA did some lunar base studies and we found that at least for the thermal control system, the night side presented more problems than the daylight. Add the fact that power from solar energy isn't available during the 14 day nights for things like heaters made for some interesting conceptual designs.





<font size=-1>[ This Message was edited by: jrkeller on 2002-06-18 23:01 ]</font>