This article is about colonization of celestial bodies. For the general definition, see here.
Colonization (or colonisation), sometimes also called space colonization and interstellar colonization, is an act of settling uninhabited, uncontested, unclaimed, or unoccupied celestial bodies with settlers in order to establish a population. In most civilizations which had reached the space age, colonization is the most common avenue for the expansion of such civilizations, aside from war and conquests. For humans, colonization have been done since the late 21st century with the discovery of warp travel, allowing a massive population boom from 10 billion to the hundreds of quadrillions of humans which now exist within the local cluster of galaxies. This article will focus mainly on the human colonization.
While humans had colonized significant portions of uninhabited regions in their own Solar System prior to the discovery of warp travel, the true rise of colonization was after the discovery of FTL travel. In the early days of colonization, pioneering groups of several individuals would have to land with meager equipment, establishing an outpost which will produce oxygen and water for themselves as they slowly constructed multiple similar empty outposts for future settlers. As the settlers arrived, some may bring the equipment necessary for some degree of food production and basic mining equipment, enabling simple construction with local materials and some degree of self-sustenance.
Eventually, such small settlements can grow to a population of up to 100 people, at which point it will qualify as an "colony". Normally, around this point some ore mining equipment will arrive (either sponsored by the government or the corporation, sometimes collectively owned by the colonists). Ores mined from the planet, or other resources (for example, harvested crops/animals in livable planets), will start to be ferried off the planet to nearby commodity markets in exchange for further food, equipment, and machinery (e.g. smelters). From hereon, the population growth heavily depends on the value of the produce of the planet - if the planet did not contain particularly valuable resources, the growth will be slow and the population might stall around 1,000-2,000 if the planet is not a naturally inhabited planet. For E-class planets, however, often even scarcely resourced planets will grow to sustain a human population in the tens of millions.
As time passes, colonization became increasingly important, and hence the technology and business surrounding it developed. Large corporations began to appear which specialize in large-scale colonization, often straight up buying rights to extract resources from entire planets and sending ships with a capacity of 10,000 colonists, who generally come from more crowded areas, to said planets. The planets will almost immediately begin industrial production of metals and such, and the profits from such endeavors fund even more colonization. In these, cases, the habitation can be large composite biodomes filled with gas (and heavily strengthened to prevent tear), or underground habitats dug into the soil. Another option for relatively well-off individuals is to establish their own self-sustaining outpost. This has grown in popularity throughout the second decamillenium, with a large number of people living in small flats and properties in Mars and other heavily urbanized planets selling their place in exchange for rights to a large portion of a small remote satellite several hundred or thousand light-years away in addition to a personal colony-ship. Upon arrival, they will tether the ship and quickly establish multiple inflatable domes (which are micrometeoroid-resistant, per regulations) along with water acquisition methods. With oxygen and water supply secured, they will be capable of sustaining themselves in the "nature". Sometimes smaller colonies grew from these as well, although having these colonies simply as vacation-homes is not uncommon practice among the rich.
If a D, S, I, or T-Class planet happened to become particularly dense in terms of population, the local populace will often gather funds for a terraforming process in order to increase habitation. For bodies in the frontier areas or regions of space perceived as vulnerable to piracy, a military garrison of varying size may be stationed on the colony. Sometimes, a colony is established on strategic positions by the military, with colonists being salaried staff to sustain the garrison or even actual military personnel executing civilian duties to sustain his/her comrades. Such colonies usually have more militants than civilians.
Alternatively, freelancers and miners may establish temporary locations in small asteroids, moons, and planets, staying in one spot for several weeks on average with some exceptions.
There is no dispute about the importance of colonization for the economic growth of any species. With the long spans of civilizations, it is crucial to continuously establish new sources of commodities to prevent and economic collapse.
While the amount of resources produced by a colony may initially be small, when a colony grows it will supply raw material that is needed to sustain manufacturing and heavy industries which are key to the large intergalactic economical system, even with all the modern industries. Without expansion in the capacity, the inevitable depletion of resources will result in a massive economical crisis. Even with the trillions and trillions of C-Units annually subsidizing millions of colonists, the Confederacy of Humanity have never reduced the colonization budget, save after the Civil War and Split of the Confederacy of Humanity. This has helped to move humans into billions of systems and over 10 billion celestial bodies, although there is still plenty of space available for the next 100,000+ years of colonization in Milky Way alone.
Politically, the position of colonies can be quite vital in securing popular support. In democratic entities, it is generally expected from a government to support colonists in their efforts, due to the public image and financial links of many colonists with their families back home. Most megacorporations, with few notable exceptions, also tend to lobby governments to increase colonization. These corporations can either be directly involved (e.g. colonial corporations) or benefited in some way (manufacturers, service providers, etc.)
However, this viewpoint on colonists, and by extension the bodies they colonize, can lead into friction between the powers in the universe. It is a widespread mindset that the first group to settle on a planet establishes a claim on said planet, regardless of the size of the planet and the group. While factually it is perfectly possible for a planet to be settled by multiple of these groups without any contact, often this will lead to a diplomatic dispute between the two home states. In extraordinary cases, this can lead to conflict, the largest of which triggered a gigantic chain reaction and kicked off the War of the Decamillenial Transition. Normally, however, such disputes will be settled diplomatically, with either one side withdrawing from the planet or a division given over it.
Below are the excerpts from the journal of BGen. Arsenio Hare Attilio (7430-7701), a CoH officer who had arrived on the small I-Class satellite Ertha-941C on 7452 (then a Corporal) with a pioneer group of 32 (4 of which were him and 3 soldiers under his command). He stayed on the colony for nine years, being promoted thrice in the time period.
March 11, 7452
Apparently I've been assigned to an icy moon 1000 km wide straight after my promotion. Ertha-941C, Major told me the name. Pretty surprised they gave a name to an average system in backwater areas. A cargo company or something wants to establish a transshipment hub in the same system and asked for security in their water-mining outposts. Better than nothing, I suppose. The Major arranged for my team to leave in three days, shouldn't be that long a journey.
March 19, 7452
0.02% the mass and one-tenth as wide, but I guess I'll have to alter my perception of "home" for the time being. At least we got lucky with the 22-hour solar day.
We entered orbit for a while to establish a global map of the satellite, and landed an hour or so after the bright white moon left the shadow of its parent. They picked a plain area near the walls of a 50 km-wide crater in the leading hemisphere. So we landed, and then woke up the captain. The wonders of autopilot, huh?
One thing they didn't tell us was that apparently this thing wasn't explored on the ground before, just a drone doing a system scan. The leader of the colonists assured me, saying that with 0.015 g you can't really go wrong.
...I kicked a small pebble halfway into orbit moments later. I should make sure Lazar doesn't pull off his stupid tricks, or we might find ourselves on the other side of this thing.
Unpacking took half a day, then another three hours to wait for our turn after the colonists finished expanding and tethering their bio-habitats. Another hour to move the furnitures in and fix them to the floor. Decided to bring down the water-harvesters tomorrow, since the shadow of the parent Ice Giant was closing in.
March 20, 7452
We setup the harvester in the "morning", and soon we're pumping out a mind-blowing two-and-a-half liters a minute. Not bad for a miniature setup twenty centimeters wide, and that works well to fill in our reduced O2 supply. More than enough for everyone, unless someone decides they want to have a dip in a hot tub. We spent the rest of the day setting up plastic algae vats along with unloading batteries, fuel, food, and other supplies. When we're done, the captain didn't feel like staying another day and left with the ship. We've still got contact with base and the home planet, but everyone seems to catch on the deserted island mood fast.
Not like there's any sea within hundreds of millions of miles, anyway.
April 2, 7452
We harvested the algae today. Apparently they don't mind the fact that the light they got is manmade considering we have just around 1/6th of the standard illumination here, so long as we put enough solar panels all over the ground. After reseeding, we had enough algae for about a month or so.
Fortunately, one of the colonists who scouted around discovered a mineral spring nearby, or we might get a case or two of food boredom-induced suicide within a week from running out of the packed meals. To prevent it later on, they spared some of the algae we harvested as feedstock for edible mushrooms.
May 15, 7452
The second wave of settlers arrived today, in a group similar to ours but with only a couple boys from the base. They've got some light machinery, so we can start manufacturing some basic construction material and plastics. Not much though.
(First journal ends here)
Later in time, the colony grew to a population of about 3,000 across the icy moon, spread in two small settlements on different areas of the planet.