Published on September 22nd, 2018 | by Andy Miles0
Space Station Earth
September 22nd, 2018 by Andy Miles
The idea of “Spaceship Earth” has been around for a while, but I prefer the idea of “Space Station Earth.” After all, the Earth has no propulsion system, but like a space station that might orbit a planet, it passively orbits the Sun. Our concepts of a space station might be more like the one in the film 2001, with its centripetal equivalent of gravity and curved floors, but the only real space station we have is the International Space Station (ISS). That is quite small, but has survived in space as a working environment for over 7000 days, which is quite an achievement, and a continuing one.
Life Support System – ISS
The ISS requires a sophisticated life-support system which manages the on-board atmosphere and the recycling of water. Oxygen is created from waste water, and hydrogen is combined with CO2 to make more water and carbon residue. Water vapor, dust, and microbes are filtered from the atmosphere, where water vapor is collected as water and everything else collected as waste. The precise levels of oxygen, nitrogen, and carbon dioxide are constantly monitored, along with humidity and the presence of any undesirable gases such as methane or ammonia, which have to be removed. About 70% of water on the space station is recycled, even urine, where pure water is extracted, and the remaining mixture of water and salts further processed. A picture is worth 1000 words, so here are a couple of schematics which show, much more clearly than I can describe, the life-support system on the ISS.
Puncture Repair Kit
Obviously, the life-support system on the ISS is critical to the lives of the astronauts on board. It is a confined space, and can quickly become contaminated or otherwise made unsuitable for the support of life. The greatest of care is taken in the design, development, and construction of all the systems on board the ISS, because many human lives depend on their working perfectly at all times. There was just recently a loss of cabin pressure and cabin air. This was traced to a docked Soyuz module. Detective work revealed that, back on Earth, a technician had accidentally drilled a hole through the fuselage, and covered up his error using glue. This had worked for a time, but the pellet of glue had degraded and become loose, and was fired out into space by the cabin pressure like a pellet from an air-gun, causing a major emergency. Everyone creating, maintaining, and operating, systems on the ISS are highly skilled operatives, highly trained, and diligent. This was a very rare error, by one person, and will probably never occur again.
Meanwhile, on Space Station Earth, there are millions of untrained, careless people, knowing nothing of the intricate balances that maintain the life-support system, creating mayhem and destruction on a daily basis. We obviously need an intensive training program to make all personnel aware of the safety protocols, and to have some idea of how the life-support system on Space Station Earth operates. The problem is that some of the Senior Officers on board are as clueless as everyone else, and in some cases seem to be going around with an electric drill in their hand and a devilish gleam in their eye, intent on mayhem and destruction all of their own making. Perhaps they are in the pay of the Vogons, to clear the decks here on Earth in readiness for its demolition, to facilitate that intergalactic highway construction project for the hyperspace express route (according to Douglas Adams, anyway).
We could do with a life-support system manual, or a kind of “Life Support Systems for Dummies,” starting with, “don’t go drilling holes in the fuselage,” or what ever counts as the fuselage here on Space Station Earth. I can’t do that much, but might manage a few tips on best practice and things to avoid at all costs.
The ISS has its relatively thin envelope of metal to separate everything inside from the harsh environment of space. It is in constant peril from all of the space junk that orbits the Earth. A nut, or bolt, or a dropped spanner, whether we see it as stationary in space with the space station hurtling towards it, or the space station peacefully floating while the debris rushes towards it, makes no difference to the result of the impact, should it occur. People keep talking about clearing up the space junk, but just like the junk in the ocean and the junk in the atmosphere, people seem much more fond of talking than acting. In 2014, flight controllers had to raise the ISS’s altitude by half a mile in order to avoid part of an old European rocket traveling along its orbital path. The problem is so bad that the International Space Station has now installed a sensor to detect when it gets hit with smaller space junk. Not satisfied with carelessly polluting Earth, we now even turn the space around our planet into a garbage pile.
Space Station Earth has a much more sophisticated system. Earth has its protective blanket of atmosphere, which is well over 35 miles (56.5 kilometers) thick, but most of it is within 10 miles (16 km) of the surface. Air pressure decreases with altitude. At sea level, air pressure is about 14.7 pounds per square inch (1 kilogram per square centimeter). That is a huge pressure. If you imagine a 10″ square, that is 100 square inches, and so is beneath 1,470 lbs of air, which is well over 1/2 ton. Over your entire body you have about 20 tons of air pressing down on you.
All this pressure is caused by gravity, which is another sophistication where Space Station Earth scores over the ISS. It is the centripetal force of gravity that prevents you flying off as you spin around at 1000 mph, and makes life on Earth much more convenient than on the ISS. It is gravity that captured and retains our atmosphere, and gravity that stops the ISS from traveling in a straight line so that it will continue orbiting the Earth, rather than heading off into deep space. The ISS is constantly falling towards the Earth under the influence of gravity, just like anything else would do, but its straight line trajectory is moving it away from the Earth at the same rate at which it is falling, so it retains its orbit.
Theoretically, the ISS, being about 250 miles from Earth, is traveling within the Earth’s atmosphere. Further out from the Earth’s surface, the gas gets very rarefied, and so it is difficult to detect when the atmosphere stops and space starts. It probably extends out as very rarefied gas to as much as 10,000 kilometers. When we say very rarefied, we mean the molecules are about a 100 kilometers apart, so barely detectable as any different from empty space.
The composition of the atmosphere is around 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.04% carbon dioxide, and small amounts of other gases. Air also contains a variable amount of water vapor, on average around 1% at sea level and 0.4% over the entire atmosphere.
The atmosphere is in a number of classified layers. The only life-friendly layer is the Troposphere, which is next to the Earth, and which extends for about 12 km, or 7.5 miles, or in aircraft terms 39,000 feet. The Troposphere is where plants and animals constantly exchange oxygen and carbon dioxide. It is here that we have our clouds and weather, so also most water vapor, and of course man-made pollution. It is actually thicker at the equator than at the poles. That is due to the centrifugal force from the spinning of the Earth. Ocean waters and people are affected in the same way, and you will weigh slightly less on the equator than you would standing on either of the poles. If it wasn’t for the Earth’s gravitational attraction, anything standing anywhere other than at the poles would be thrown out into space by the centrifugal force, or to put it more accurately, instead of traveling in a circle at about 1000 mph, as you do now, you would begin traveling in a straight tangential line from the Earth’s surface. That would be because of the ending of a force, and not the presence of a force, so what we call “centrifugal force” is not really a force at all. The only real force is the centripetal force, of gravity in this case, forcing you to follow a curved trajectory on the face of the Earth when your natural inclination is to travel in a straight line (in accordance with Newton’s first law of motion).
After the Troposphere comes the Stratosphere, which extends to about 55 km, or 34 miles. Here, the pressure is only one thousandth of the pressure at sea level, and the air is very still. It contains the ozone layer, a very important part of our life support system, which protects us from lethal ultraviolet radiation. Above that are the Mesosphere, Thermosphere, and Exosphere, which takes us out to 85 km, 1000 km, and 10,000 km respectively. In the Thermosphere, the gas is so rarefied that molecules can be a kilometer apart. The ISS orbits within the Thermosphere at a height between 350, and 420 km, which is between 220 and 260 miles.
That blanket of air is a very versatile part of our life support system. It regulates temperature and gaseous exchanges to keep air breathable, transports water to keep the land wet, and gives us drinking water, and finally, protects us from meteoroids large and small, which burn up from friction as gravity accelerates them towards the Earth at high speeds. Harmless dust will often make it down to the surface because it is not traveling fast enough to burn up. Anything up to about an inch in diameter will tend to burn up completely as it is heated to 1600 C, making the bright meteor trails. About 95% are burned out this way. Anything bigger than that will tend to break up into smaller parts that make it to the ground sometimes as meteorites. So, mainly we are protected. A man-made space station with a thin metal skin is, by comparison, like a tin can in a shooting alley.
Large objects, classified as asteroids, we are not protected from, but visits from these are few and far between. With these larger objects, the pieces of rock falling from the sky are not even the greatest concern. What causes the most damage is the shock wave produced by the meteor when it breaks apart in Earth’s atmosphere. For example, the Chelyabinsk meteor — an asteroid the size of a six-story building that entered Earth’s atmosphere in February 2013 over Russia — broke apart 15 miles (24 km) above the ground, and generated a shock wave equivalent to a 500-kiloton explosion, injuring 1,600 people. These events are rare, so for the most part, our “shield” does its job all day, every day.
A bombardment of objects is not the only thing we need protection from. There is a fierce “solar wind” emitting from the Sun constantly, which is a stream of high energy particles. Ordinarily this would crash into our atmosphere, and over a period, quite literally blow it away. This brings us to a hugely important element of our life-support systems, the Magnetosphere: this is the magnetic field around Space Station Earth, thought to originate from the very high temperature iron core at its center. The temperature at the center of the Earth is reckoned to be about equal to that at the surface of the Sun.
Structure of the magnetosphereAn artist’s rendering of the structure of the magnetosphere: 1) Bow shock. 2) Magnetosheath. 3) Magnetopause. 4) Magnetosphere. 5) Northern tail lobe. 6) Southern tail lobe. 7) Plasmasphere
On the dayside of Earth, the magnetic field is significantly compressed by the solar wind to a distance of approximately 65,000 kilometers (40,000 mi). Earth’s bow shock is about 17 kilometers (11 mi) thick and located about 90,000 kilometers (56,000 mi) from Earth. This is way beyond the 10,000 kilometers of the outer atmosphere, so this keeps the solar wind well away. On Earth’s nightside, the magnetic field extends in the magnetotail, which lengthwise exceeds 6,300,000 kilometers (3,900,000 mi). Earth’s magnetotail is the primary source of the polar aurora.
Balance of Gases
So, the magnetosphere is that part of our life support system which protects the main life-support system of our atmosphere. We have not discussed in any detail exactly how that part of the life-support system operates. It is said a person can survive for 3 weeks without food, 3 days without water, but only 3 mins without air. The part of the air that we need is that 20% oxygen, and we need it to remain at 20%. If we had too little oxygen, we would be gasping for breath. If we had too much carbon dioxide, we would feel sleepy and lethargic, and eventually lose consciousness. The balance has to be just right. The balance is maintained by our symbiotic relationship with plants, where plants expire oxygen during the process of photosynthesis, in which they use sunlight to combine carbon dioxide with water to create hydrocarbon molecules. We breathe in oxygen, oxidize hydrocarbon molecules, and expire carbon dioxide. So the plants on earth are actually part of our life-support system. We obtain 50% of our oxygen from land-based plants, and the other 50% from ocean-based plants. On land, we have forest giants, but in the ocean, the plants we depend on for our life are microscopic life-forms, called phytoplankton. Phytoplankton exist at the surface of the water, which is rich in carbon dioxide and nutrients. However, an excess of carbon dioxide is slowly making the oceans more acidic, man-made pollution such as micro-plastics are poisoning the water, and temperatures are rising above the optimal range for phytoplankton to live. If we lose the phytoplankton, then we lose half of our oxygen supply. When that occurs, then perhaps those who think that their life depends on how much money they have in the bank will realize that we cannot breathe money. So, it is vital that we protect the integrity of the oceans and protect all life within them.
In the UK, where I live, it has been estimated that we would need to plant a forest the size of Yorkshire (one of the largest Northern counties in England) to absorb sufficient carbon dioxide to meet our Paris agreement obligations. Network Rail, the organization responsible for maintaining the railway network, has chosen to cut down millions of healthy trees at the side of railway lines in order to save the bother and expense of managing them. So, the reality is, we have fewer trees rather than the more that we need.
In other parts of the world, people are cutting down huge areas of rainforest to make temporary plantations for palm oil, which we don’t really even need. Huge amounts of carbon dioxide are absorbed — and oxygen created — by the world’s rainforests and huge forests in the cooler north, but all of these forests are endangered by human activity. If we lost all of these forests, that would be most of the other 50% of oxygen production, gone. It is essential therefore, that all the world’s forests must be protected and nurtured, to ensure they continue to perform their vital function for our life-support system.
Some actions have hidden consequences. For example, the warming of the Atlantic Ocean has increased rainfall in the Brazilian rainforest by 10% above normal. All of our ecosystems are so very sensitive, and interconnected, and a substantial increase in rainfall could have serious but unpredictable consequences. We really need to learn to be very very careful and cautious in everything we do, and to show the utmost respect for our life-support system here on Space Station Earth.
Currently, we are so irresponsible and careless that it is highly unlikely that our life-support system will survive our own foolish actions. Greenhouse gases are actually part of our life support system, because they keep the average temperature of our planet at around 14°C. Without them, Space Station Earth would be very cold and inhospitable. The control of temperature is a combination of the level of greenhouse gases, the level of solar activity, and our precise orbit around the sun. Climate scientists are able to plot the cycles of change in all of these. They are able to predict cycles of warming and cooling. In the past there have been both very warm periods and ice age periods, when everywhere was very cold. Right now, we should be moving into a cooling period, and yet the planet is warming rapidly. Since the beginning of the industrial revolution we have been pumping endless quantities of greenhouse gases into the atmosphere.
These greenhouse gases are comprised of:
- Carbon dioxide through burning fossil fuels
- Methane from fossil fuel extraction and leakage, and also from farm animals and the decomposition of waste material
- Nitrous oxides from diesel exhausts, other combustion processes, and from soil bacteria fed by artificial nitrogen fertilizers
- Hydrofluorocarbons (HFCs) from refrigerants (we used to use chlorofluorocarbons (CFCs), but they were eliminated as a pollutant because they damaged the ozone layer)
- Increased water vapor arising from the warming we have already caused (This will make it warmer as it becomes warmer, in a never ending loop)
Careless Folks Cost Lives
This massive increase is causing rapid temperature rises. Just like any other life-support system, the mechanism has to be carefully balanced, but we are being totally irresponsible and reckless. The warming we have caused is causing other changes which themselves contribute to further warming, so creating a feedback loop which will become self sustaining and possibly unstoppable. We are like the small boys on the hill-side, finding it easy to rock the boulder to get it moving but powerless to halt its trail of destruction once it is under way.
So, we really need to be super-careful about removing anything that absorbs carbon dioxide, and how much carbon dioxide we put into the atmosphere, because there is no thermostat on Space Station Earth, and careful control of greenhouse gases is the only way we can control the temperature.
On the ISS, systems are largely separate. There is some interconnection but not much. On Earth all the systems are very interconnected. As air gets warmer it is able to hold more water vapor, so temperature and water are interconnected. When air is warmed it moves up, but because the Earth is spinning, the rising air begins to circulate in what is called a cyclone, like a whirlpool. There are all kinds of circulations and currents at different levels. The winds mix up the air, which keeps it fresh and breathable and transports water vapor. Warm low-lying air over the oceans picks up lots of water, and then when it rises and cools or meets cold air, some of that water vapor starts to fall as rain drops. All our water on land depends on that constant circulation of winds bringing rain. But too much warming makes the rains heavier and the winds stronger, and makes dry spells longer and hotter, so that weather becomes more extreme. Messing up the temperature messes up the winds and the rain and everything.
Disruption of Agriculture
Messing up the climate like that has an impact on a further important part of our life-support system, which is agriculture. Space Station Earth has no supply ships like the ISS. Our current agriculture depends on our current climate where it rains at particular times and yet is dry at others, and where the amount of rainfall is just right for the crops that we are growing. Too much rain can cause root crops to rot in the field. Heavy rain at the wrong time can batter down grain crops, making them hard to harvest. Wet grain cannot be stored, and has to be dried at great expense of money and energy. Agriculture is invisible to many modern people. Many children think that food comes from the supermarket, and have to be educated to understand how it is produced. Many adults take the fully stocked supermarket shelves for granted. One of the most likely impacts of climate change to have significant effect early on will not be rising seas, or people dying of heatstroke, but serious disruption to agriculture. When the supermarket shelves are empty, think how long it will take for civilization to break down.
Despite all of these dire consequences of our actions, and the interconnected nature of all of the elements of the life-support systems on Space Station Earth, its inhabitants continue to carelessly destroy and disrupt those systems. Never could the old saying, “sawing off the branch on which we sit” be more applicable.
Ten Survival Rules for all Space Station Earth Personnel
Here is a list of things to add to “not drilling holes in the fuselage” to ensure your survival on Space Station Earth:
- Do not burn, or cause to be burnt, any fossil fuels of any kind including coal, gas, oil, and fuels refined from oil (in fact, avoid burning anything that produces pollution).
- Do not buy, produce, or cause to be produced, anything which cannot easily be recycled, and ensure that all waste you produce is fully recycled.
- Do not buy, produce, or cause to be produced, any “product” which cannot be fully processed and eliminated from the end product of the waste water purification system.
- Do not introduce chemicals, plastics, fats, oils, or other unsuitable items into the wastewater system. Everything introduced there has to be properly and fully processed and only pure water returned to the main holding tank, otherwise known as the ocean. For the avoidance of any doubt, “chemicals” includes all manner of products on supermarket shelves for cleaning your self and your home.
- Do not buy, use, or cause to be used, noxious chemicals and artificial fertilizers in your garden or agricultural fields. These kill pollinators and render the soil infertile. Use only organic farming and gardening methods.
- Take full responsibility for all you acquire, including any packaging, to ensure it is responsibly disposed of at the end of its life.
- Do not use more energy than is necessary. In total we must not use more than the amount that renewable energy sources can supply. Thankfully, this is increasing.
- Do not use more water than is necessary. Water is currently in increasingly short supply — do not waste it.
- Do not eat bovine meat or dairy produce, because bovines produce 100 billion liters of methane every day. Animal rearing also uses precious water resources, is the most inefficient way to produce food, and produces mountains and lakes of waste material.
- Do plant trees and wildflower meadows where there is room for them, and do not destroy forests or buy products arising from their destruction, e.g. palm oil.