> Afaik gas pressurized fuel feed for rockets was abandoned > since the 1950's. No ? What do you mean by pressurized fuel feed? The Ariane 5 rocket uses helium to pressurise the oxygen and hydrogen tanks during flight, to maintain the feed pressure out of the tank as the fuel is used AIUI. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist