Space Environments for Humans

Summary

Space environments for humans concern the potential development of habitats, spacecraft, and techniques that will allow humans to create and live in sustainable environments in space, such as space stations, or on planets and satellites like the Moon or Mars. Advances in space science, engineering, and technology since the mid-twentieth century resulted in plausible scenarios for human colonization of space, as well as means for harvesting and using extraplanetary resources for purposes of human settlement. Although no definitive off-Earth scenario that addresses how humans will live in space yet exists, it appears possible that human environments in space will remain a subject of concern for scientists, engineers, space agencies, and technologists into the future.

Definition and Basic Principles

Although human settlement in space has not become a scientific reality, three major space initiatives allowed scientists and technologists to realize the first stages of creating long-term human living environments in space. The first was a series of National Aeronautics and Space Administration (NASA) programs—Mercury, Gemini, and Apollo—culminating in a successful lunar landing in 1969 and subsequent return trips to the Moon. The second and third developments were the successful deployment of NASA’s space shuttle program and several Earth-orbiting space stations—including, most notably, Russia's Mir, China's Tiangong, and the International Space Station (ISS). The data collected from these projects broadened scientific understanding of the possibilities of long-term human survival in various space environments and opened up possibilities for continued ventures in space.

Areas of continuing research related to human environments in space include the effects of solar and other types of radiation on spacefaring humans and their spacecraft, the availability of extraplanetary resources that could sustain human life in space and power the spacecraft, the creation of materials to protect humans in space or on other planets, realistic colonization prospects for humans on other planets or satellites, funding and management of space projects related to human environments in space, and the determination of whether living in space is a realistic option for human beings.

Scientific research continues as scientists, space agencies, and technologists grapple with such questions. This is largely the result of scientific curiosity, and the knowledge gained from living and working in space adds to understanding how people interact with their home planet. However, because of environmental issues such as global warming and possible energy shortages, there are also major concerns about the continued sustainability of Earth and its resources for human habitation.

Background and History

A long-established subject for science-fiction and fantasy writers, the dream of living and traveling widely in space and on other planets precedes the scientific reality of being able to do so. Much of what has been discovered about the needs of humans in space environments was learned during the space race in the 1950s and 1960s when the Soviet Union and the United States competed to see who would be the first nation to put a man in space and return him safely to Earth. Also adding to knowledge of the effects of spaceflight on humans were the subsequent missions in NASA’s space shuttle program and the many space stations launched since the 1970s. By this time, scientists had recognized that space habitats for humans could become viable options for space programs.

In the years before space travel, however, many scientific visionaries considered the special needs of environments for humans in space. Russian scientist Konstantin Tsiolkovsky, for example, was a pioneer in theorizing about spaceflight. Among Tsiolkovsky’s numerous influential ideas were the space elevator (a contraption anchored to Earth that would allow travel high into Earth’s orbit without the use of rockets) and the notion of colonizing space as an answer to the potential dangers faced by humans on Earth, such as catastrophic impacts from solar bodies. Similar concerns are still used as justification by some parties in insisting that space colonization is an important next step for humankind.

In the twenty-first century, the idea of building space environments for humans is still alive and, more than ever before, has taken on an international tone. Numerous nations, including the United States, Russia, China, Japan, and India, have been considering flights to the Moon and Mars, and some have made plans for the creation of permanent or semipermanent lunar and Martian bases, as well as long-term journeys within the solar system.

In the early twenty-first century, commercial space travel companies started developing technology for space travel, exploration, and colonization. In 2002, entrepreneur, engineer, and investor Elon Musk founded Space Exploration Technologies, known as SpaceX, to design inexpensive rockets, launchers, and spacecraft. In 2016, Musk unveiled preliminary plans for colonizing Mars at the International Astronautical Congress. He further developed the plans and published them in 2018 in New Space. Musk's plans include the development of a fully reusable rocket booster and spaceship, called Starship, for missions to Mars. Starship became the most powerful and largest rocket flown at the time of its build and was successfully launched and tested throughout the 2020s.

How It Works

Because of the harsh conditions awaiting humans in off-Earth environments, special consideration must be given to the protective clothing worn by spacefarers, as well as the protective materials that will be used to build their stationary and floating habitats. Just as important is the design of habitats in which humans live and work, as well as the resources that will power their habitats and vehicles and possibly even feed entire colonies. Likewise, spacecraft engineering is vital for transportation to bases or colonies or for craft used as living quarters.

For space environments for humans to become feasible, further research and development must take place in three main areaslife-support systems and shielding, types of space-bound habitats, and resources to sustain habitat populations. Given the vast number of possibilities within these scenarios, there are many considerations that will take precedence over others as humankind progresses toward a more developed future in space. For example, the operating conditions, power resources needs, and amenities aboard a habitat built for long-term, near-Earth orbit will be very different from those for a round-trip to the Moon or Mars. Despite these differences, there are many other areas in which research and development could uncover certain universally applicable materials and techniques.

Space Habitats. Since it was first understood that it is possible to live in an off-Earth environment, many designs have been proposed to accommodate humans in diverse space environments. The only living and working environments ever used by humans in space have been the capsules used to transport astronauts to and from the Moon and space shuttles and space stations launched into orbit from Earth. In the case of the lunar capsules, each was designed for a short voyage of less than a month’s duration. Similarly, space shuttles, while offering a wider range of movement than capsules and more storage capacity, were not designed for human habitation out of Earth’s atmosphere. Space stations, however, because of their size and the ability to add modules (modular compartments, designed for many purposes, whether personal, scientific, or operational), offer a glimpse into what orbiting habitats will probably be like during the initial stages if spacefaring becomes more common. They are also durable and can be built to the discreet specifications of the vessel sponsor.

Several types of habitats are needed for humans to live in space, such as housing, storage, and work areas. NASA and other space agencies have considered establishing base camps on the Moon and even Mars. One plan uses torus-shaped designs that can be inflated and connected together in a manner similar to inflated inner tubes connected to each other by portals. The tori would be constructed of highly durable protective fabric that is light enough to transport from Earth to the Moon. Other possible designs include the use of bunkers dug into the surface of the Moon. The advantage of this design is that, instead of being exposed to the extremely cold air on the Moon, the bunkers could be temperature-regulated and have a natural barrier—the surface regolith (soil)—against cosmic rays. Other proposed habitats include designs for mobile vehicles that can be joined together for periods of time to form base camps and separated for movement when appropriate.

Life-Support Systems and Shielding. The physiological effects of the weather and atmospherics awaiting astronauts in space and on extraplanetary bodies differ from those found on Earth. For example, long-term exposure to solar radiation can cause significant health problems for astronauts. In addition, continuous living and working in zero-gravity environments can lead to cardiovascular problems, loss of bone density, muscle atrophy, and many other issues that can lessen the productivity of astronauts and even cause life-threatening conditions. A further consideration is protection from meteoroids that can damage machinery and habitats. With these things in mind, designs for special protective suits and gear are being created that will lower exposure to solar particles and energy. The protective suits will also encourage efficient oxygen circulation and regulate temperature and air pressure, flexibility and mobility, and weight and comfort.

Life-Sustaining Space Resources. Because of the very high cost of supplying life-sustaining resources such as oxygen, water, food, and power from Earth, vessels and habitats will likely need to become self-reliant. Gathering, storing, and manufacturing these resources once initial launch supplies are depleted remains a significant issue. Although orbiting space vessels will remain reliant on terrestrial sources, lunar and Martian colonies may be able to extract some of these things from the available space resources. Scientists think that water and oxygen can be processed from lunar regolith, giving those settlements a nearly endless source of these resources. Power generation could easily be solved using solar units, but only during the lunar day, which lasts fourteen days. During the other fourteen days, lunar settlers would probably have to use a different power source, such as battery cells and possibly even power resources from satellites.

Applications and Products

Human-inhabited environments in space have many potential uses, and like many of humankind’s earliest journeys on Earth, they will be expensive and potentially hazardous. They may also be extremely rewarding and alter the course of human endeavor for centuries to come. However, as of the early twenty-first century, space programs were directed toward exploration rather than settlement.

Lunar and Martian Bases. The space shuttles and manned space stations traversing the sky are used for scientific research. Lunar or Martian bases would most likely be used similarly but could offer more data on various subjects. They would be constructed in environments that allow the study of such topics as the capabilities of natural resource development in space, the long-term effects of non-Earth atmospheres and conditions on humans (also plants and animals), the social and psychological effects of spacefaring, and the technological capabilities of the human race. These are very broad subjects but are essential to understanding the requirements of continuing to voyage into space.

Mining and Harvesting of Space Resources. Human settlements in space could help solve specific resource needs faced by humans on Earth, such as environmental and power needs. One proposed endeavor would be to use lunar regolith as a source of energy that could be beamed back to Earth through microwaves. Other possibilities include using the helium-3 found in the lunar soil as a fusion-power source to fuel rockets. Helium-3 could also be used for Earth’s power needs if proper transport was arranged. Perhaps the most important use for resources found in space would be to sustain human settlements and help them become self-sufficient.

Space Tourism. Since 2001, a handful of wealthy, private individuals have traveled into space as tourists aboard Russian spacecraft. Willing to pay tens of millions of dollars, these so-called space tourists are the first clients of a potentially lucrative—although hazardous—international space tourism industry that may someday offer trips to low-Earth-orbit hotels, space stations, and lunar or Martian bases. The cost of such trips is likely to decrease over time until, for example, short-term trips into orbit cost tens of thousands of dollars. Before space tourism becomes common, this industry will likely be heavily regulated.

Several commercial space travel companies offer flights to private space tourists, including SpaceX, Virgin Galactic, and Blue Origin. In May 2020, NASA astronauts were sent to the ISS using SpaceX Crew Dragon spacecraft, making it the first private firm to transport governmental astronauts.

Living and Traveling in Space. Each new space venture helps determine whether people can live in orbit or on other planetary bodies. Once the feasibility is determined, it will open the door for many considerations that have remained merely speculation. Questions and areas for research include whether it will be possible to create environments that can grow into self-sufficient human settlements, perhaps with farms and industry as a source of income; space law; whether human settlements need governance in the same way colonies once did; and whether space colonies might seek independence from or become hostile to governments on Earth.

Careers and Course Work

Many career paths are available in the area of space environments for humans. For those interested in creating and designing these habitats, focus should be given to space biology, space engineering, computer science, robotics and embedded systems, nanotechnology, and aeronautics because space environments will draw on the knowledge of workers from all these areas. To become involved in the use of these environments, some of these same areas of focus will be needed, but the quickest path to doing so is to become an astronaut. To be a NASA astronaut, one needs to meet basic science and math requirements and hold a bachelor’s degree or higher in an area of biological or life science, engineering, or math. Professional experience in the military and aviation could be of use to students seeking a career in piloting spacecraft. Universities such as Harvard University in Massachusetts and Princeton University in New Jersey offer courses in space science.

Although relatively small, the industry that has grown around the needs related to space environments for humans is a highly technical field. There are many very specialized areas of focus for technicians, project managers, and other workers, many of whom will have to acquire advanced degrees in their fields of study to be considered for even entry-level jobs. Some careers, such as robotics and embedded systems engineers, require degrees in computer science, while others, such as environment designers, need a degree in engineering or physics. Aspirants can work as space science web developers and space system engineers.

Social Context and Future Prospects

Humans may someday use environments in space as regularly as they use terrestrial spaces. Space environments may be used as private living spaces for entire families and public spaces for commerce. Of course, these are merely dreams, but by identifying what humans need to survive in space—whether it is clothing, habitats, or means of transportation—and by building these things, humans will move one step closer to making those dreams a reality.

The first phases of learning about the needs of humankind in space have come and gone. The days of the first space race between the United States and the Soviet Union taught space scientists and astronauts the fundamentals of taking humans into space and returning them safely to Earth. However, research is allowing people to envision far more than short-term journeys. For example, the space suits designed for NASA’s Constellation program (CxP) are made for a variety of purposes and time frames. Similarly, the types of habitats that have been envisioned appear to be small-scale versions of what could someday become cities in space (either floating or stationary). In short, scientists no longer worry about whether humans can survive in space environments but instead about which designs will be used first and for what purposes.

NASA stated that the atmosphere inside the spacecraft is critical to an astronaut's life, as microorganisms could change in space and easily transfer in closed environments. In addition, due to adverse conditions, stress hormones can affect the immune system and lead to certain illnesses. However, NASA consistently takes care of such situations. For example, it used thermal control systems technology to monitor the air quality of space stations to ensure the environment's safety, breathability, and sound composition.

However, humankind is not yet living in space. Unlike science-fiction stories in which entire civilizations are packed into starships and shipped out across the galaxy and beyond, plausible plans for living in space are limited to the concerns of the small groups of astronauts involved in these plans' initial test runs. Growth in the space science and exploration industry is likely due to national and international interests, corporate concerns, and people’s desire to take the next steps toward human-friendly space environments.

Bibliography

Criscuolo, François, et al. “Human Adaptation to Deep Space Environment: An Evolutionary Perspective of the Foreseen Interplanetary Exploration.” Frontiers in Public Health, vol. 8, no. 119, 24 Apr. 2020. doi:10.3389/fpubh.2020.00119.

Harris, Philip. Space Enterprise: Living and Working Offworld in the Twenty-First Century. Scholars Portal, 2019.

Henion, Leigh Ann. “Space Tourism Will Surely Be a Blast, But Can It Also Improve Life on Earth?” The Washington Post, 30 Nov. 2017, www.washingtonpost.com/lifestyle/magazine/space-tourism-will-surely-be-a-blast-but-can-it-also-improve-life-on-earth/2017/11/28/c9abfa40-c3f2-11e7-aae0-cb18a8c29c65‗story.html. Accessed 28 Mar. 2018.

Howe, A. Scott, and Brent Sherwood, eds. Out of This World: The New Field of Space Architecture. American Inst. of Aeronautics and Astronautics, 2009.

Moon, Walt K. Rockets and Space Travel. BrightPoint Press, 2023.

Musk, Elon. “Making Life Multi-Planetary.” New Space, vol. 6, no. 1, 1 Mar. 2018. doi:10.1089/space.2018.29013.emu. Accessed 28 Mar. 2018.

Tironi, Martín, et al. Design for More-than-Human Futures: Towards Post-Anthropocentric Worlding. Routledge, 2024.

Seedhouse, Erik. Tourists in Space: A Practical Guide. 2nd ed., Springer, 2014.

"The Human Body in Space." National Aeronautics and Space Administration, 16 Apr. 2024, www.nasa.gov/hrp/bodyinspace. Accessed 27 June 2024.

Thirsk, Robert, et al. “The Space Flight Environment: The International Space Station and Beyond.” Canadian Medical Association Journal, vol. 180, no. 12, 2009, pp. 1216–1220.