A Standard Atmosphere is a type of atmosphere known for possessing a pressure, temperature, constituent gases, and other factors all within tolerable limits of sophonts that are conventional lifeforms
- Standard atmospheres are suited to Aslan, Droyne, Hivers, Humans, K'kree, and Vargr.
- The entire atmospheric designation system is sophonticentric to these Major Races.
An atmosphere rated as Standard has a mean surface pressure ranging from 0.71 atm to 1.49 atm.
Surface Pressure & Water Properties
Surface Pressure & Water Properties Surface
0.7 atm 90°C 1.0 atm 100°C 1.5 atm 111°C
History & Background (Dossier)
On Earth, sophonts have little experience of differing atmospheric pressures, and so many underestimate how much of an impact this factor may have on everyday life. Terran inhabitants are actually living near the bottom of an ocean of air. At sea level, the weight of the air presses down on its inhabitants with a pressure of 1.0 kg per squared centimeter. At higher altitudes, less air means less weight and less pressure. The pressure and density of air decreases with increasing elevation.
Standard pressure is what a Terran at sea level regularly breaths. The IISS Atmosphere Core Manual tells us that a Standard Atmosphere has a pressure between 0.71 and 1.49 times that of Earth. Things change at lower pressures and those sophonts who live or work in mountainous regions can attest to those changes. 
References & contributors (Sources)
- Marc Miller. Worlds and Adventures (Game Designers Workshop, 1977), 5.
- J. Andrew Keith. Exotic Atmospheres (Game Designers Workshop, 1983), 1-16. (Special Supplement 2 from the periodical Journal of the Travellers' Aid Society 17)
- Marc Miller. Referee's Manual (Game Designers Workshop, 1987), 22.
- Joe Fugate, J. Andrew Keith, Gary L. Thomas. World Builder's Handbook (Digest Group Publications, 1989), 64-68.
- Terrance McInnes, Dave Nilsen. World Tamer's Handbook (Game Designers Workshop, 1994), 11-17.
- Jon F. Zeigler. First In (Steve Jackson Games, 1999), 70,72.
- Paul Drye, Loren Wiseman, Jon F. Zeigler. Interstellar Wars (Steve Jackson Games, 2006), 125-6.
- Gareth Hanrahan. Mongoose Traveller Main Rulebook (Mongoose Publishing, 2008), TBD.
- Marc Miller. T5 Core Rules (Far Future Enterprises, 2013), 409.
- Paul Elliott. The Universal World Profile (Zozer Games, 2016), TBD.
- Author & Contributor: Lord (Marquis) and Master of Sophontology Maksim-Smelchak of the Ministry of Science