Sounds dangerous.
2007-01-23 11:00:02 · 3 answers · asked by nowyermessingwithasonofabitch 4 in Science & Mathematics ➔ Astronomy & Space
who are they?
2007-01-23 11:09:36 · answer #1 · answered by Todd C 4 · 0⤊ 2⤋
If you pressurize a space capsule with air, you need to pressurize it to about 10 pounds per square inch in order to keep the human inside happy.
If you pressurize with pure oxygen, you only need to pressurize it to about 3 pounds per square inch to keep the human happy.
The human only really cares about the "partial pressure" of oxygen, and need that to be around 3 psi, regardless of the total pressure.
The capsule wall, however, cares a great deal about the difference between 3 psi and 10 psi. Basically, the wall thickness (and the total weight of the capsule, which drives the whole weight of the rocket) is proportional to the internal pressure it must contain.
As far as dangerousness is concerned, the fire hazard is approximately the same for a given partial pressure of oxygen. In other words, the fire is like the human, caring only about the total amount of oxygen in the capsule, and not (much) about the other, non-reactive gasses. So a pure oxygen atmosphere at 3 psi is not much more dangerous than air at 10 psi.
2007-01-23 19:09:40 · answer #2 · answered by cosmo 7 · 6⤊ 0⤋
Believe it or not, to reduce weight. Not the weight of nitrogen gas, but the pressurized bottles of it.
Addendum: Cosmo's answer is great, but Apollo 204 had 100% pure oxgyen at 16.7 psi. Normal atmospheric pressure is 14.7 psi. Read excerpt of CASS's report of the Apollo 204 disaster. Cabin pressure of the Mercury capsule was 5.5 psi, 100% oxygen.
2007-01-23 19:08:03 · answer #3 · answered by Scythian1950 7 · 0⤊ 0⤋