The top of the sky
Stories from Physics
for 11-14
14-16
The Armstrong limit is defined as the altitude at which atmospheric pressure is such that water will boil at body temperature. On Earth, the Armstrong limit is between 18 and 19 km above sea level. Above the limit, the human body cannot survive in an unpressurised environment and exposed bodily fluids, such as saliva and tears, will boil away. Unprotected bodies suddenly exposed to altitudes above the Armstrong limit risk explosive decompression which may cause tearing to the lungs, due to the pressure difference between the inside and outside of the body.
References
The top of the sky
M. von Ehrenfried, Stratonauts: Pioneers Venturing into the Stratosphere, Chichester, Praxis Publishing, 2014, p. 6
E. Seedhouse, Suborbital: Industry at the Edge of Space, Chichester, Praxis Publishing, 2014, pp. 71-72
House of Commons, Transport Committee, Flight time limitations: first report of session 2012-13, London, The Stationary Office, 2012, p. 49
