In thinking about this amazing journey astronauts take, we had one very important question. How do astronauts breathe while they are living on the International Space Station? Actually, astronauts get the oxygen that they breathe from water. As you have learned in science classes, water is made up of 2 hydrogens and 1 oxygen molecule.
Scientists have found a way to break down that water into its basic molecules through a process called electrolysis. While the equipment used on the International Space Station is very complex, the process is something you can easily try at home.
During their four-month stay, the crew will rely on the Station's hardware to provide breathable air. Each molecule of water contains two hydrogen atoms and one oxygen atom. Running a current through water causes these atoms to separate and recombine as gaseous hydrogen H 2 and oxygen O 2. The oxygen that people breathe on Earth also comes from the splitting of water, but it's not a mechanical process.
Plants, algae, cyanobacteria and phytoplankton all split water molecules as part of photosynthesis -- the process that converts sunlight, carbon dioxide and water into sugars for food.
The hydrogen is used for making sugars, and the oxygen is released into the atmosphere. However, "the chemical-mechanical systems are much more compact, less labor intensive, and more reliable than a plant-based system," Perry noted. Hydrogen that's leftover from splitting water will be vented into space, at least at first. NASA engineers have left room in the ECLSS hardware racks for a machine that combines the hydrogen with excess carbon dioxide from the air in a chemical reaction that produces water and methane.
The water would help replace the water used to make oxygen, and the methane would be vented to space. Right: The oxygen that humans and animals breathe on Earth is produced by plants and other photosynthetic organisms such as algae. Various uses for the methane are being considered, including expelling it to help provide the thrust necessary to maintain the Space Station's orbit. At present, "all of the venting that goes overboard is designed to be non-propulsive," Perry said.
The ISS will also have large tanks of compressed oxygen mounted on the outside of the airlock module. These tanks will be the primary supply of oxygen for the U. After that, the tanks will serve as a backup oxygen supply. Once the reaction starts, it continues to burn until it's all used.
That's why you have to give it a tug to begin the flow of oxygen. At present, carbon dioxide is removed from the air by a machine on the Zvezda Service Module based on a material called "zeolite," which acts as a molecular sieve, according to Jim Knox, a carbon dioxide control specialist at MSFC.
Oxygen in the rest of your body will also expand. You'll balloon up to twice your normal size, but you won't explode. Your skin is elastic enough to hold you together. Any exposed liquid on your body will begin to vaporize.
So the surfaces of your tongue and eyes will boil. Without air in your lungs, blood will stop sending oxygen to your brain. You'll pass out after about 15 seconds. It's also very cold in space. You'll eventually freeze solid. Depending on where you are in space, this will take hours, but if you're close to a star, you'll be burnt to a crisp instead.
0コメント