Imagine living in a place where your survival depends upon living within your limits, not consuming more food and energy than you produce, creating enough fresh water and air to live on, reducing waste to a bare minimum, recycling everything that you can, and avoiding contaminating the environment around you. This is what astronauts must face, to an extent, on board the International Space Station , and what they would have to face to a greater extent in future settlements on the moon or Mars . But it's also how we have to live on Earth if we are to protect our environment, which is one of the themes of this year's World Space Week , running between Oct.
4 to Oct. 10. A space station, or a lunar base, is largely a closed-loop system.
What we mean by this is that it must produce its own resources and then recycle them, feeding them back into the system because they are limited. Consume too much, and astronauts might run out of air, food, water or energy, which could be fatal. Sure, there are occasional resupplies from Earth, however, so they are not 100% closed loop systems.
What is a completely closed loop, however, is Earth itself. Spaceship Earth Think about it. Our planet has a certain carrying capacity, or what the Club of Rome — a think-tank of academics, business leaders and politicians — called the " limits to growth " in their famous 1973 report.
They warned that Earth was beginning to reach its carrying capacity, and soon we would be generating too much energy, e.