Self-sufficient human colonies beyond Earth are necessary for humanity to survive into the distant future. Building them will not be easy, as many scientific and technological challenges still remain. Here we will focus on what is needed to create an offworld society that is capable of surviving and thriving on its own. We’ll use Mars as an example since it’s the most likely candidate location for the first independent offworld colony.
Unlike Earth, Mars cannot provide the basic necessities of human life. To live there, we will need to use technology to acquire everything we need to survive. A successful Mars colony must have the hardware and skilled personnel needed to produce its own air, food, heat, and electricity – among other things. Colonists will need to be able to remove or reprocess their own waste on an ongoing basis. If a colony achieves all of this, they’ll have taken the first major step towards self-sufficiency: keeping colonists alive for weeks to months.
Living independently off-world for years to decades requires much more. Nothing lasts forever, including life support hardware and the technical experts who maintain it. At a minimum, a capable colony will need to be able to repair and replace the hardware that supports it. Similarly, it will need to be able to rear and educate people to have the expertise needed to survive and contribute.
But even that isn’t enough. An existentially independent colony must have the industry and size to not only replace capabilities as they are gradually lost; it must also be capable of robust growth. If the colony cannot grow each of its interlinked capabilities, it is at the mercy of the next accident or catastrophe. A colony that cannot grow will stagnate and eventually perish.
For humanity to survive the loss of Earth, offworld colonies would have to be capable of surviving and thriving if even their most important trade partner was gone. This includes the ability to produce new life-supporting and industrial production equipment. Mars may be host to the first independent colony (or colonies). Alternately, perhaps a network of colonies throughout the solar system may together become so capable that they would be able to survive the loss of Earth by working together.
Mars is a materially rich world, waiting for an intellectually mature species to make good use of it. If humanity is to survive in the long run, we need to spread to the stars. The first step on our journey is settling beyond the cradle of the Earth. We need colonies that are capable of growing their own industry and population. To achieve this, we’ll need to overcome specific technological and logistical challenges. We live in very exciting times as it seems likely that many of these challenges will be confronted during the next few decades.