From: utzoo!decvax!cca!David.Smith@CMU-10A@sri-unix Newsgroups: net.space Title: Specific impulse & chamber pressure Article-I.D.: sri-unix.1457 Posted: Thu May 13 22:02:22 1982 Received: Fri May 14 05:33:26 1982 From: David.Smith at CMU-10A (C410DS30) I have read a couple of times (AW&ST, not recently) that the SSMEs develop a chamber pressure of 300 bar (atmospheres). I have also read a couple of times (FLIGHT International) that the Ariane's first stage engines develop about 55 bar. Is such a difference credible? I would expect exhaust velocity and specific impulse to be directly related to the chamber pressure. Such a difference in specific impulse seems hard to swallow.