Earth’s atmosphere has a mass of about 5.15 X 1018 kg. The oceans total about 1.335 X 109 cubic kilometers. Earth’s land area is about 1.5 X 108 square kilometers. Because of this vastness for almost all of our history, we have polluted our oceans and air, cleared forests, and engaged in destructive farming practices with little adverse effect. Historically because of small numbers and lack of mechanized ability human impact on the Earth was largely inconsequential. Not so today. We have drastically increased population numbers and industrial-scale destruction and pollution. That is not to say we as citizens of this planet have not taken action. However, many of our solutions will be practical only here on Earth.

Living in Space is our only option if future human civilizations continue to expand. Whether humans settle in detached orbiting colonies or on the surface of the Moon or Mars they will live encapsulated in relatively small spaces. For life to succeed with any permanence the settlements will need to be self-sustaining. At a minimum, they will require fully functional ecosystems capable of maintaining an optimal atmosphere, clean water, adequate food supply, and a system of maintaining Earth-equivalent gravity. I believe they will also need to provide diversity in plants and animals in a way that mimics specific local habitats on Earth.

Producing Earth gravity in space can only be done using centripetal force. Materials science has yet to create strong enough to counter a centripetal force of 1G. However, there are indications carbon microfiber materials could be developed that would be strong enough. Biological systems are the real challenge. Maintenance of a safe atmosphere would require a complete absence of polluting emissions. Food preparation would be centralized in special kitchens that could control volatiles and recycle all food waste.

Even open composting of organic waste would not be safe in closed-space environments. On Earth, many commercial composting systems have no effective mechanism to control what goes into compost collection bins. Therefore, unknown toxins might be returned to the soil or enter the groundwater and the food chain. The fermentation process in open composting releases large quantities of carbon dioxide and methane and perhaps other noxious gases into the atmosphere. Currently, monitoring finished compost for toxins is often done by a method similar to the ‘canary in the coal mine test’. If the canary died in its cage deep underground the miners hopefully were evacuated before they suffocated. The ‘canary test’ is done on finished compost by determining how well it supports plant growth.

A company in Watsonville California plants cucumber seeds in the compost and does a rate of a germination test. While this passes the compost in a practical way it does not identify any pesticides, herbicides, or other toxins that may be present. To reduce CO2 and CH4 emissions compost piles are frequently aerated from the bottom to allow the growth of some oxidative organisms. Again, because of the very large volume of Earth’s atmosphere and seas, the net effect of open composting is more beneficial than detrimental. This system will not work in space habitats.

The relatively small enclosures in future space settlements will require a perfectly balanced ecology. I have heard the term ‘ecotopia’ used to describe such an ecology. This ecotopia would need continuous monitoring and interventions as evolution and the dynamics of species interactions are never static. As a result, there will be a need for environmental scientists, ecologists, molecular biologists, botanists, and environmental engineers to converge their knowledge in support of these environments. The scientists as a collective would be granted complete control of the space habitat’s life support environments.

Fungicides and pesticides are part of much of modern farming. Those chemicals increase the rate of soil death and would not be tolerated in a space colony environment. Fungicides play a major role in this process. Killing microbes (bacteria and fungi) in the soil reduces plant growth and speeds up the process of desertification as the soil becomes lifeless dirt. Pesticides are a significant cause of pollinator colony collapse. The use of these poisons as well as aerobic tilling practices has been a standard of agribusiness, especially in First World countries.

In Part 2 of Ecotopia in Space Begins on Earth(linked) of this blog post, I will reveal the current work progressing here on Earth to create partial ecotopian systems. There is a very promising technology that may soon scale to an effective commercial operation.