Word: oxygenate
(lookup in dictionary)
(lookup stats)
Dates: all
Sort By: most recent first
(reverse)
...other hand, an oxygen-nitrogen system has serious drawbacks for space flights. The additional storage tanks, valves, tubing and instruments necessary to blend and monitor a two-gas atmosphere would add an estimated 500 lbs. to a spacecraft the size of the Apollo...
Unlike a pure-oxygen system, which requires a cabin pressure of only 5 lbs. per sq. in., a two-gas system would have to approximate the sea-level pressure on earth-14.7 lbs. per sq. in.-to ensure that enough oxygen reached the astronauts' lungs. If a small meteorite should puncture the skin of a ship containing a nitrogen and oxygen atmosphere and cause rapid decompression, the astronauts on board would develop a painful and perhaps fatal attack of the "bends"; nitrogen dissolved in their bodies would come out of solution, forming gas bubbles in tissues...
...been less concerned about weight; they have employed a two-gas system from the beginning of their manned-space program. It has proved awkward in at least one of their space missions. Before Cosmonaut Aleksei Leonov could leave Voskhod II for his space walk, he had to breathe pure oxygen (to rid his body of dissolved nitrogen and avoid the possibility of bends). He then entered an air lock, sealed his suit, gradually lowered its pressure to about 3 lbs. per sq. in. (so that it would be less inflated and more flexible) and only then was able to open...
Having considered all of these possibilities, NASA decided in the late 1950s that a space-mission failure was more likely to occur because of the added complexity and weight of a two-gas system than because of the fire hazard of a pure-oxygen system. Designers spared no efforts to fireproof the Mercury, Gemini and Apollo spacecraft. All electrical wiring was coated with noncombustible materials. Devices capable of sending out sparks were placed in sealed boxes. Space suits, seats, instruments and cabin walls were all designed to avoid the generation of static electricity...
...more than seven years, during 1,024 hours of successful space flight and thousands of ground tests in pure-oxygen atmospheres, NASA's reasoning seemed sound. There was no apparent need for conversion to a two-gas system-a conversion that would require the complete redesign of the spacecraft and could set the Apollo program back two years. But in 14 terrible seconds at Cape Kennedy, NASA's carefully considered decision has been thrown open to question...