Henry Spencer wrote HS> No, most of it is a derivative of a commercial high-temperature insulating HS> foam, CPR-421, a "urethane modified isocyuranate foam". They'd originally HS> planned to use BX-250, the same commercial spray-on closed-cell HS> polyurethane foam used on the later S-IIs, but the heating environment got HS> too severe for it. The aft dome has a different formulation for higher HS> heat loads, and several other foams are used in various minor roles.
HS> Most of the foam is one inch thick; there is more in some areas. HS> (Caution: this is from a 1983 paper -- there may have been some change HS> along the way since.) Meanwhile I found the following: "The entire outer surface of the external tank is insulated with a half inch thick cork/epoxy layer covered with 1 to 2 inches of spray-on foam" (Damon, 1995, p. 134). Im trying to get a feeling of how damaging a chunk of isolation could be. But eventually one has to consider that most of the mass of a torn of piece of insulation could consist of frozen moisture. In the moment a piece of insulation gets loose it has the same velocity as the whole vehicle, how important would be the relative velocity at the moment it would impact on the orbiter? Hans Ulrich Ammann mailto:[EMAIL PROTECTED] http://www.spl.ch _______________________________________________ ERPS-list mailing list [EMAIL PROTECTED] http://lists.erps.org/mailman/listinfo/erps-list
