The selection of spacecraft and space suit atmospheres for future human space exploration missions will play an important, if not critical, role in the ultimate safety, productivity, and cost of such missions. Internal atmosphere pressure and composition (particularly oxygen concentration) influence many aspects of spacecraft and space suit design, operation, and technology development. Optimal atmosphere solutions must be determined by iterative process involving research, design, development, testing, and systems analysis. A necessary first step in this process is the establishment of working bounds on the atmosphere design space.Lange, Kevin E. and Perka, Alan T. and Duffield, Bruce E. and Jeng, Frank F.Johnson Space CenterSPACECRAFT DESIGN; SPACE SUITS; DESIGN ANALYSIS; ATMOSPHERIC PRESSURE; LIFE SUPPORT SYSTEMS; SYSTEMS ANALYSIS; SPACE EXPLORATION; PRODUCTIVITY; INTERNAL PRESSURE...