Space colonization

Space colonization is a largely theoretical topic and refers to the future establishment of permanent off-Earth human settlements, whether on space stations or bases on other planets, moons, or asteroids. Factors such as climate change, resource depletion, overpopulation, pollution, and wide-scale disasters could one day render Earth uninhabitable, leading many top scientific experts to conclude that space colonization will be necessary for the survival of the human race. In addition, the anticipated development of space-oriented private industries, such as mining, power generation, and sub-orbital and orbital space tourism, may necessitate the development of artificial human habitats in space.

Taking an extremely long-term view, astronomical modeling predicts that the Sun's outer layers will expand and swallow up Earth in approximately 7.6 billion years. Space colonization will be an absolute necessity if humanity is to subsist beyond this inevitable event.

Background

One of the earliest realistic conceptions of space colonization dates back to the 1920s, when visionary European scientist Herman Potočnik forwarded an idea about the future development of a round spacecraft that rotates on its own axis, creating internal gravity while using a system of concave mirrors to harvest sunlight and turn it into energy. While Potočnik's contemporaries largely dismissed the concept as a flight of fancy, it was later taken up by world-renowned physicist Gerard O'Neill during the 1970s. The British Interplanetary Society, a space research consortium, also endorsed Potočnik's model, which was noteworthy given the fact that the society had accurately anticipated that humans would visit the Moon some thirty years before American astronauts reached it—a time when such an achievement seemed impossible.

Sending human astronauts to Mars is one of the primary and most immediate goals of space exploration programs. Beyond the potential for groundbreaking study of the Martian environment, such an initiative would lay the theoretical groundwork for possible future human habitation of Mars. Despite the popular appeal of this idea, the National Aeronautics and Space Administration (NASA) stresses that the first human settlements in space are far more likely to be based on orbiting space stations than foreign celestial bodies such as Mars or the Moon. According to NASA, orbiting space colonies offer many inherent advantages over basing settlements on other satellites or planets in the solar system.

NASA cites several factors in support of this hypothesis. It would be far easier to create Earth-like gravity in an orbiting space station than it would be in a colony based on the Moon, Mars, or any other celestial body with gravity levels that deviate significantly from those found on Earth. Orbiting colonies would be easier for resupply missions to reach and could efficiently harvest solar power from the Sun. The zero-gravity nature of interplanetary space would make it possible to build larger colonies, as structures suspended in space would be virtually weightless and therefore very easy to place. Additionally, locating space colonies as close to Earth as possible would make more economic sense. They would be easier to reach, thus facilitating more efficient trade and commerce.

Overview

The aforementioned NASA space colonization theory assumes that human technology will continue to advance along predictable lines and precludes the possibility of exotic technological developments that could overcome the limitations associated with colonizing other planets or satellites. Thus, it takes what is widely considered a realistic view of space colonization, at least in terms of the relatively near future. Experts generally agree that the first space colonies would likely be based in artificial structures that orbit Earth. Regardless of the form they might eventually take, all human space colonies will require a common set of specific features and capabilities, no matter where they are located.

Space colonies will have to offer a level of gravity that is very similar, or identical, to that found on the surface of Earth. The axial rotation model first proposed by Potočnik would likely align very closely with the reality of the first human space colonies. Space colonies will require self-sustaining biospheres, protection from incoming solar radiation, communication technologies, and energy sources. Again, Potočnik's original idea of capturing sunlight and harvesting its energy provides a pragmatic path forward. Colonists will need stable, comfortable internal temperatures, sources of food and water, the ability to generate oxygen, and the ability to recycle oxygen, waste, and water.

At present, technological limitations make building such a space colony unfeasible. It currently costs thousands of dollars per pound of weight to complete a launch from the surface of Earth into near-Earth orbit. The systems that would provide oxygen, water, the recycling of materials, and protection from solar radiation are far from refined. World-famous theoretical physicist Stephen Hawking predicted in 2016 that it would be at least one hundred years before humans were able to create a self-sustaining, permanent space colony.

However, in the early twenty-first century, technology was advancing at a rate never before seen in history. Private companies such as SpaceX joined public agencies such as NASA in the quest to advance the capabilities of space exploration, and some of the most optimistic predictions suggested humans could visit Mars by the 2030s. Space is also being investigated as a possible site of human economic expansion, with space tourism, space-based solar power generation, and the mining of minerals, precious metals, and other space resources from satellites and asteroids all inching toward feasibility.

If humans were to attempt to establish permanent settlements on other celestial bodies within the solar system, several possible sites have been suggested. Mars and the Moon are leading candidates, given their relative proximity to Earth and the well-developed scientific understanding of their topographies, geologies, surface conditions, and climates. The moist, mild cloud-tops surrounding Venus have been proposed as a possible colonization site, as have the larger members of the asteroid belt and some of the rocky moons orbiting Jupiter and Saturn. Advancing beyond the solar system might become possible in the distant future, creating the possibility of eventually relocating human life to an Earth-like exoplanet.

Some scientists suggest that colonization of other celestial bodies may be pursued through terraforming, in which the entire environment of the planet, moon, or asteroid in question is transformed to better suit humans. If successful, such a process would greatly reduce the amount of technological infrastructure a colony would need to be self-sufficient. In particular, Mars has been proposed as a candidate for terraforming due to its similarities to Earth and the presence of water. However, other scientists suggest the enormous energy input and complex engineering required for hypothetical terraforming make such a process unrealistic. In 2023, the US Defense Department initiated a study to determine the infrastructure and capabilities needed to establish a moon-based economy over the next decade.

If an extraterrestrial environment cannot be altered to match humans' biological needs, the challenge of colonization becomes far greater. Scientists have found that living with non-Earth atmospheric and gravitational conditions causes many physical and mental problems, which would need to be dealt with for colonists to survive. While technological solutions may exist, some futurists suggest space colonists could use genetic engineering to adapt to space environments, potentially even leading to evolution away from standard human biology.

Bibliography

Burgess, Matt. "Hawking: Space Colonies Won't Exist for at Least 100 Years." Wired, 19 Jan. 2016, www.wired.co.uk/article/stephen-hawking-black-holes-space-colonies. Accessed 31 July 2024.

"Catalyzing an Integrated Lunar Economy: Initial Results of the LunA-10 Capability Study." DARPA, 10 May 2024, www.darpa.mil/news-events/2024-05-10. Accessed 31 July 2024.

"The Colonization of Space." The Week, 26 Nov. 2018, theweek.com/articles/808840/colonization-space. Accessed 31 July 2024.

Cozby, Warren R. Nuts and Bolts of Space Colonization: A Practical Plan for the Colonization of the Solar System. Davis Brothers Printing, 2010.

Creighton Jones. "Understanding the Biological Significance of Cosmic Radiation and Electromagnetic Factors for Human Space Colonization", AIAA SPACE 2013 Conference and Exposition, AIAA SPACE Forum, (AIAA 2013-5347). dx.doi.org/10.2514/6.2013-5347. Accessed 31 July 2024.

Dirks, Nicholas. "The Ethics of Sending Humans to Mars." Scientific American, 10 Aug. 2021, www.scientificamerican.com/article/the-ethics-of-sending-humans-to-mars/. Accessed 31 July 2024.

"NASA's Journey to Mars." NASA, 1 Dec. 2014, www.nasa.gov/content/nasas-journey-to-mars. Accessed 31 July 2024.

Robson, David. "The Expert Guide to Space Colonies." BBC Future, 2 Oct. 2014, www.bbc.com/future/story/20141002-time-to-plan-a-space-colony. Accessed 31 July 2024.

Schwartz, James S. J., and Tony Milligan. The Ethics of Space Exploration. Springer Publishing, 2016.

Smith, Cameron, and Evan T. Davies. Emigrating Beyond Earth: Human Adaptation and Space Colonization. Springer Science & Business Media, 2012.

"Space Colonization." NASA HQ Library, www.nasa.gov/headquarters/library/find/bibliographies/space-colonization/. Accessed 31 July 2024.

"Space Settlement Basics." NASA, 2004, nss.org/settlement/nasa/Basics/wwwwh.html. Accessed 31 July 2024.

Williams, Matt. "The Future of Space Colonization—Terraforming or Space Habitats?" Phys.org, 10 Mar. 2017, phys.org/news/2017-03-future-space-colonization-terraforming-habitats.html. Accessed 31 July 2024.