2What is Galactic Colonization? Galactic colonization is the concept that humans, or any intelligence, can spread their individuals throughout the universe by establishing “colonies” in outer space and on various celestial bodies.Colonization, much as it was for the European colonizers of centuries ago, would be partly for survival , partly for curiosity and partly for profit.
3Why Colonize?The sun has ~2 billion years before it uses up its lifespan. This will not be a survivable situation for life on Earth whatsoever.There are over 530,000 known asteroids and possibly trillions of comets in our solar system alone. These have devastated Earth before.The Milky Way is ~4 billion years from colliding with the Andromeda galaxy.The galaxy is rich in natural resources that are rare or not found on Earth. These can be mined and put to use on Earth and beyond. The moon, for example, has a relative abundance of Helium-3, which is rare on Earth, that could be used in fusion reactors to power the entire globe for centuries.
4Why Colonize?“for example, the smallest Earth-crossing asteroid 3554 Amun (see orbit) is a mile-wide (2,000-meter) lump of iron, nickel, cobalt, platinum, and other metals; it contains 30 times as much metal as Humans have mined throughout history, although it is only the smallest of dozens of known metallic asteroids and worth perhaps US$ 20 trillion if mined slowly to meet demand at 2001 market prices”
5Why Not?Space travel isn’t entirely practical. Current costs for each kilogram launched into space range from $4,000 to $40,000. To build infrastructure to mine and colonize extraterrestrial bodies would take an unprecedented initial investment.Some argue that humans should not export their wars and waste to other places in the galaxy.
6How to Colonize: Overcoming the Challenges Most of the expense of space travel comes from building, maintaining, and launching complex launch vehicles from the Earth’s surface. Each space shuttle orbiter cost ~$1.7 billion to build; each mission cost an average of $450 million.Earth based launch vehicles use most of their weight on fuel. The Space Shuttle weighed ~4.5 million pounds at liftoff. ~4.2 million pounds of this weight was from fuel, fuel tanks, and boosters.The further a mission goes, the more fuel and money it takes to launch from earth. The shuttle flew at a relatively low orbit.
7How to Colonize: Overcoming the Challenges The answer to cost and fuel problems is to assemble and fuel vehicles in space.Large vehicles can be assembled piece by piece in space, fuelled, and sent outward to other planets, comets, and asteroids.Once infrastructure is built up, these vehicles can even be formed from elements mined in space, avoiding escaping Earth’s atmosphere and gravity altogether.
8How to Colonize: Overcoming the Challenges The nearest star to the Earth (other than the sun) is Proxima Centauri. It is 4.5 light years away. The fastest proven technology could take a spacecraft there is ~19,000 years.Nuclear pulse drives, though purely theoretical, would still take ~85 years to transport humans to Proxima Centauri.Objects at the most optimistic speeds would face serious risk of hitting micrometeoroids. They would also need a way to decelerate.
9How to Colonize: Overcoming the Challenges The proposed Alcubierre drive would greatly diminish time required for interstellar travel, allowing for faster than light travel within the constraints of Einstein’s equation.An Alcubierre drive would contract space in front of it and expand space behind it, thus travelling faster than light without exceeding the speed of light in its frame of reference.By simply “bending the road,” we can reach destinations faster without increasing our speed.This concept works in theory, but needs better technology to be applied to reality.
10How to Colonize: Overcoming the Challenges Long term space travel has a negative effect on health.Muscle atrophy, bone density loss, and macular degeneration are all linked to long space voyages.Psychological effects also exist. Space travel has always been, and will likely continue to be, done by isolated individuals or small groups. The most people ever in space at one time was thirteen. This could create adverse psychological reactions.No emergencies can be immediately treated, even in the relatively close orbit that the ISS occupies. Medical care is entirely dependent on the crew.Radiation is also incredibly high beyond low-Earth orbit.A round trip to Mars would, using current technology, take eighteen months. This is far longer than anyone has ever stayed in space.
11How to Colonize: Overcoming the Challenges Research on adverse health effects is ongoing onboard the ISS.Centrifugal force can replicate gravity. A habitable wheel structure spinning at sufficient speed would simulate gravity for its inhabitants. This would negate almost every negative heath effect of space travel.Radiation can be negated with adequate shielding.Robots are increasingly able to do almost anything a human can. Not only that, but artificial intelligence can provide companionship in isolation.
12Making New WorldsIf we can reach other planets and establish enough infrastructure, theorists suggest that we could mold or “terraform” these worlds to be more like our own.Mars, Venus, Europa, and even the moon are all candidates for terraforming.Terraforming would take centuries at least, and would consist of slowly changing the atmospheres of celestial bodies to resemble our own.This would eliminate the need for spacesuits or contained environments on the planets that undergo it.
13Are There Other Colonizers? If extra-terrestrial civilizations exist and have advanced far enough, then it is entirely likely they are already colonizing and may have been doing so for millennia or more.They may have already executed their own versions of terraforming throughout the galaxy.One day, such colonization could lead to contact… or conflict.We must assume that any other colonizers face many of the same challenges as us.We simply don’t know for sure yet.
14In Conclusion:People have only been in space for 51 years. We can only assume that we are just beginning to realize the possibilities of spaceflight.There is many benefits to reap from large-scale colonization, but it would require an expensive global effort unlike anything humans have ever done.If there are other civilizations out there, they may be in the act of colonizing, and this could one day lead us to interact with them.