The board concluded that astronauts would continue to breathe pure oxygen in their space suits before and during launch to reduce the risk of developing the bends or decompression sickness, since once in orbit the CM's environmental control system would gradually replace the mixed-gas atmosphere with pure oxygen and ...
Pure oxygen was used in the case of the Apollo I because the alternative of using mixed gases did not allow for a breathable atmosphere. In addition, the fire safety checks assumed that there would be no flammable hazards that could pose any threat to the astronauts.
The cabin was pressurized with 16.7 pounds per square inch (psi) of 100 percent oxygen, a pressure slightly greater than one atmosphere. With everything just as it would be on February 21, the crew went through a full simulation of countdown and launch.
Breathing only oxygen gets rid of all the nitrogen in an astronaut's body. If they didn't get rid of the nitrogen, the astronauts might get gas bubbles in their body when they walked in space.
The atmosphere in the Apollo spacecraft was 100% oxygen, at a pressure of five pounds per square inch. The oxygen system constantly added fresh oxygen to the cabin to replenish that breathed by the crew. Carbon dioxide exhaled by the astronauts was removed by canisters of lithium hydroxide, like this one.
On March 14, 1968, NASA announced that Apollo 7, the first manned Apollo mission planned for October 1968, would use a mixed-gas atmosphere of 60% oxygen and 40% nitrogen at a pressure of 16 psi during operations on the launch pad.
Because the cabin had been filled with a pure oxygen atmosphere at normal pressure for the test and there had been many hours for the oxygen to permeate all the material in the cabin, the fire spread rapidly and the astronauts had no chance to get the hatch open.
The high concentration of oxygen can help to provide enough oxygen for all of the organs in the body. Unfortunately, breathing 100% oxygen for long periods of time can cause changes in the lungs, which are potentially harmful.
Breathing air containing 21% oxygen risks acute oxygen toxicity at depths greater than 66 m; breathing 100% oxygen there is a risk of convulsion at only 6 m.
However, astronauts in the Gemini and Apollo programs breathed 100 percent oxygen at reduced pressure for up to two weeks with no problems. And you don't need to worry about ever breathing 100 percent oxygen except in rare cases.
The review board identified several major factors which combined to cause the fire and the astronauts' deaths: An ignition source most probably related to "vulnerable wiring carrying spacecraft power" and "vulnerable plumbing carrying a combustible and corrosive coolant"
Haste for space
Perhaps the Apollo 1 fire could have been prevented if the United States had not been caught up in a race to get to the moon. On the other hand, it's important to remember that NASA was attempting to do something that had never been done before, and that comes with an inherent risk, Chiao noted.
On Jan. 27, 1967, fire broke out at Cape Canaveral Air Force Station Launch Complex 34. Fueled by an exhaustive and fast-burning oxygen-rich atmosphere, the Apollo 1 command capsule ignited from the inside out.
A hundred feet above the surface of the Moon, Mission Control confirms they have 60 seconds of fuel left before Armstrong has to make the decision to abort. If they run out of fuel before they land, they will crash and most likely die as there is no possibility of a rescue mission.
Time was running out. The Apollo 11 lunar module was on its historic descent to the moon's crater-pocked surface on 20 July 1969 when a fuel light blinked on. Still 100ft (30 metres) above the ground, it was not what the astronauts needed. The Eagle's tank was nearly dry.
The TLI placed Apollo on a "free-return trajectory" - often illustrated as a figure of eight shape. This course would have harnessed the power of the Moon's gravity to propel the spacecraft back to Earth without the need for more rocket fuel.
To breathe pure oxygen at that level for any longer can have toxic results, including "shock lung," or adult respiratory distress syndrome. In infants, too much pure oxygen for too long a time can also lead to retinal problems as the blood vessels in their eyes won't develop properly.
If you take in more oxygen than your body needs, it can slow your breathing and heart rate to dangerous levels. Too much oxygen can lead to oxygen toxicity or oxygen poisoning. This can happen if you accidentally take in too much supplemental oxygen or use oxygen therapy when you don't need it.
Breathing air containing 6 to 10 percent oxygen results in nausea, vomiting, lethargic movements, and perhaps unconsciousness. Breathing air containing less than 6 percent oxygen produces convulsions, then apnea (cessation of breathing), followed by cardiac standstill.
Between the damage from the oxygen you breathe, the food you eat, ionizing radiation, plus the normal damage from cell division, all that can drive aging—not just by causing cancer but also through cellular degeneration.
Upon breathing pure oxygen from OXY99 oxygen cylinder, you will feel rejuvenated as if a wave of fabulous energy just dashed through your body. It releases energy inside your body immediately upon breathing oxygen.
If the concentration of nitrogen is too high (and oxygen too low), the body becomes oxygen deprived and asphyxiation occurs.
"Fire!" Then a garbled transmission, and then the final plea: "Get us out!"
On Jan. 27, 1967, a fire swept through the Apollo 1 Command Module during a launch rehearsal test, tragically killing the three astronauts trapped inside. Astronauts Gus Grissom (left), Ed White (middle), and Roger Chaffee (right), died on Jan.
U.S. Air Force pathologists conducted examinations, concluding that the astronauts died of asphyxia from carbon monoxide and other toxic gases resulting from the fire. The burns they received were likely survivable. at Arlington National Cemetery.