Dave,

I look forward to your article about the air brushing. I hope you are going to give us a name, instead of the usual unnamed source. I also hope that you give us some detailed information, like where she worked, how long she worked, her boss, etc. The reason I say this is that I live in the heart of manned space flight here in Houston and I know many people, from grunts to big wigs who worked on Apollo. I'll see if her credentials check out.

I hate to say this but I tricked you on the Hasselblad question. Mainly to see if you know what you are doing. When someone states "did you do a thermal analysis of the camera," anyone who is a thermal person immediately knows what that means. That does not mean subjecting a piece of hardware to an arbitrary temperature range, it means determining the temperature range that a piece of hardware attains under various environmental conditions. As Jay has already pointed out, a black asphalt road is much hotter than its surroundings. On the moon, this asphalt surface would be much hotter because there is no convection to the air and conduction through the lunar soil is very low. The question that needs to be asked here is this "If you were going to test the asphalt what temperature would you use, the temperature of the surrounding air or the temperature that the asphalt reaches during a full sun condition?" The answer's quite obvious.

In space, the temperature of an object is determined by how much solar energy it absorbs, how much infrared energy it absorbs and how much infrared energy it emits to deep space. (For you purists, I made my comments simple and one could state that the geometric factors are already included in my statements.) So to keep an object cool (or make it hot) in space, all one needs to do is to coat it with the right materials.

Since you quote Jan Lundberg quite extensively he could probably give you the thermal analysis report for the Hassalblad camera. Then you would know exactly what temperature to use. There is one very telling statement in your own website, "Protective plates were added to the case and film magazine." From my viewpoint as a thermal person, that sounds like NASA wanted to added some protection to avoid excessive tempertures.

BTW, if I find a thermal analysis report on the Hasselblad camera, I be more than happy to send you a copy. You'd be amazed as the things I find here at garage sales.



<font size=-1>[ This Message was edited by: jrkeller on 2002-05-29 17:57 ]</font>