Future Humans: Will Our Bodies Become Multiplanetary?

On a Friday afternoon at SpaceX headquarters in Hawthorne, California, I wait for my brother Karl, an aerospace engineer for the company in a lobby. A security guard checks my ID card and informs me that I am not allowed to take pictures inside the compound. When Karl arrives, he leads me into a large, open warehouse where welders and engineers work. First, he shows me mission control, a room enclosed by glass windows where engineers manage rocket launches and space flights. Further along, he points out an area where engineers construct the Dragon, a spacecraft designed to deliver both people and supplies to the international space station and then return to Earth, bringing down the cost of space missions by making the rocket reusable. Workers mill around and stop at the company café for free coffee and frozen yogurt. They wear shirts that say “Occupy Mars,” and play the Star Wars and Star Trek soundtracks while they work. After the tour we return to the lobby, where I notice a poster bearing the image of a green planet with no oceans. Karl explains that the image is a terraformed Mars, transformed to resemble Earth and become a suitable habitat for humans. 

According to the company website, “SpaceX designs, manufactures and launches advanced rockets and spacecraft. The company was founded in 2002 to revolutionize space technology, with the ultimate goal of enabling people to live on other planets.” I often dream of space travel, imagining what extraterrestrial life would look, sound, and feel like. How would the human body transform in the microgravity environment of Mars? Would humans born on Mars have different anatomical features than humans born on Earth? Pondering the effects of gravity reminds us that humans are not independent, or bounded entities. Rather, we are part of landscapes, physical forces, and non-human objects. We are literally formed by everyday conditions on Earth, such as gravity, temperature, and humidity. Indeed, the body’s appearance and shape are not intrinsic.

The Body in Space

Rachel Ellman is one of SpaceX’s crew medical engineers. She compiles medical kits for astronauts, and she works on making life systems, space suits, humidity levels, and food supplies optimal for astronaut wellbeing and comfort. Ellman comes to SpaceX from MIT, where her dissertation research documented the effects of simulated partial gravity on rodent bodies (Ellman 2014). On a second tour of SpaceX, my brother and I asked her questions about human bodies in microgravity environments, testing details found in the Red Mars science fiction series, which tells the story of human colonies on the planet. The characters in the series terraform Mars to resemble Earth, and they create extreme sports games supported by the planet’s microgravity environment. In the story, humans born on Mars are taller and more graceful than humans from Earth, but they also have osteoporosis.

Ellman says that undoubtedly, people who spend significant time in space or on Mars would suffer from osteoporosis.“Any animal that has evolved to in a 1G environment is not equipped to live in zero gravity or microgravity,” Ellman says. The effects of space on human bones are especially pronounced. Astronauts become osteoporotic and are prone to hip fractures upon returning to Earth if they spend several weeks on the international space station. They exercise to maintain bone density, but this only works to some extent. Any human born on Mars would not likely be able to survive on Earth due to their decreased bone density, although we do not know this for sure. Martians may also be longer and leaner than humans on Earth due to less gravity. However, reduced weight load would change the shape of the bones, but how the bone shape would develop is unknown. Zero gravity has been studied, but partial gravity is impossible to research, Ellman says. We can simulate it, but we are unable to truly study it since humans and animals have not yet visited to Mars. She speculates that partial gravity may be similar to zero gravity, although probably less marked.

The human body experiences other difficulties in the zero gravity environment of space. The cardio-vascular system shrinks because the heart muscle does not have to work as hard to pump blood as it does on Earth. Astronauts report that they urinate blood, and they eventually lose 50% of their blood volume, since they do not tolerate liquid in the body while in space. Astronauts return to Earth dehydrated and prone fainting. They lose calluses on their feet since they spend long periods of time without walking, and their feet become sensitive. Astronauts have trouble urinating in space and catheters are always included in astronaut first-aid kits. Further, the human vestibular system is used to sensing 1G. Without gravity, astronauts feel motion sickness. “Everyone throws up for the first two days. And then they return to Earth, they puke again while they are adjusting to gravity,” Ellman says. Karl and I decide that space tourism sounds like a terrible idea, and we briefly feel pity for those who would pay Virgin Galactic $250,000 US dollars, only to vomit for three days. Additionally, astronauts are at risk of developing cataracts due to exposure to ultraviolet and Gamma rays in space.

Human Bodies and the Alive-ness of non-Humans

Gravity is a lot like infrastructure. It rules our earthly lives, but we are not conscious of it most of the time. Starr, who argues that it is necessary to study infrastructure, or the “boring” and “mundane,” argues that one only notices infrastructure when it fails. “The normally invisible quality of working infrastructure becomes visible when it breaks: the server is down, the bridge washes out, there is a power blackout,” she asserts (1999: 382).  Similarly, one may only notice gravity and its deep relationship to human bodies when it is absent. If SpaceX succeeds in its mission to make human life multiplanetary, we may indeed see and feel visible changes to the body in its absence.

Studying the body in space reminds us that human bodies are intimately related to their surrounding environments and that non-human forces act on, and ultimately shape, them. Our bodies are is in a constant process of becoming. Robbins argues that we “typically think of objects and things in the world as discrete” (2012: 94). When looking at a tree, we do not often think of its actions of drawing nutrients from the soil, pushing through concrete, or of its status as “momentary, differentiated and becoming.” In reality, however, the tree “becomes the way it is through a constant remaking of other things” (ibid).  Similarly, we tend to think of the human body as discrete, and its components shaped by genetics. A human femur is a human femur, generally with a similar shape and density to other human femurs. We rarely consider that the femur as constantly subject to the pull of gravity and other outside sources.

Several scholars argue that human bodies are connected to, and continuously shaped by, their environments. Kosek, for example, describes in a seamless way that bodies are in a continuum with their environments and part of the landscapes they inhabit. In the opening of his ethnography on conflicts over land use in northern in New Mexico, he argues that human bodies are literally part of a drug trade highway. “The history of production, distribution, and consumption of heroin across nations and borders, into the streets and arroyos of Chimayo and through the veins of Chicano bodies has had profound effects on the region,” he argues (2006: xiv).  Later, he describes landscapes as an “embodiment, an internal part of, or appendage, to a social body” of humans (ibid: 107).  “To be Hispano,” he writes, “is to have a special relationship with the forest, one that relies on that attachments of bodies to landscapes through idioms of nature” (ibid: 107).  In interviews, Hispanos spoke of forests and trees like fingers on hands, and of their bodies and personal and family histories as possessing roots like trees. Later, he discusses radiation from Los Alamos in New Mexico as a ghostly presence that deteriorates Hispano bodies (ibid: 231).  Radiation, though invisible, acts on the human body, sickening it until it becomes unsustainable.

Similarly, Jane Bennett asserts that landscapes and non-human objects and entities act upon, and disrupt human bodies and activities. She argues that non-humans possess “vital materiality,” or aliveness. “Vital materiality,” she writes,

captures an ‘alien’ quality of our own flesh, and in doing so, reminds humans of the very radical character of the fractious kinship between the human and the nonhuman.  My ‘own’ body is material, and yet this vital materiality is not fully or exclusively human.  My flesh is populated and constituted by different warms of foreigners (2010: 112).  

Further, Bennett argues that agency is not exclusive to humans: “Non-humans --trash, bacteria, stem cells, food, metal, technologies, weather—are actants more than objects” (ibid: 115). She borrows the term “actant” from Latour, who defines it as “something that acts or to which activity is granted by others. It implies no special motivation of human individual actors, or of humans in general” (in Bennett, 2010: 9). 

Gravity, zero gravity, and microgravity are actants. They are like appendages to the human body, as they allow and/or restrict human growth and movement. The human body is in process, and it is continually shaped by gravitational force on Earth (or the lack of gravity in space in the case of astronaut bodies). Gravity shapes human bones, circulatory systems, vestibular systems, and feet. A human born on any other planet besides Earth would likely have a bone density, bone shape, and blood distribution distinct from bone density on Earth.  Similarly, if Earth had a stronger gravitational pull, our bones would be denser and our heart muscles would be stronger due to its need to work harder to pump blood. The lack of gravitational force in space shows in a very literal and small-scale way that human bodies are in a constant dialectic with non-human forces, which contribute to the continuous creation of humans. 

The Future

The unknowns of how the human body will survive in space long-term may ultimately limit efforts to terraform Mars. According to Ellman, the human body is always surprising. “We do not know exactly how it will react on Mars.” One cannot predict how and if humans will survive in environments outside of the planet where we evolved.

Space exploration is often presented as Earths “Plan B.” Elon Musk, the founder of SpaceX argues that no life form can survive if it is confined to a single planet. In an interview, he describes Mars colonization as “extinction insurance”:

I think there is a strong humanitarian argument for making life multi-planetary in order to safeguard the existence of humanity in the event that something catastrophic were to happen, in which case being poor or having a disease would be irrelevant, because humanity would be extinct. It would be like, ‘Good news, the problems of poverty and disease have been solved, but the bad news is there aren’t any humans left (Anderson 2014).

Besides the ethics of saving humanity, Musk asserts that space exploration and making life multi-planetary is the next stage in human evolution, on par with significant stages of species development such as biodiversity and consciousness. Karl, echoing Musk, argues that space exploration must start now in order to save humanity in the long term. We must start to think about traveling to other worlds as soon as possible if we as a species are to escape the problem of the sun becoming a red giant in five billion years. 

Karl and Ellman both agree, however, that Earth is the ideal habitat for humans and that it must be protected and preserved. Mars should not be a Plan B. Ellman especially emphasizes the unknowns of long-term human settlements in partial gravity on the body. Many puzzles and problems must be solved before any kind of long-term space habitation can technologically and ethically happen. We are products of the conditions on Planet Earth. Who and what will we be when those conditions are eliminated?

Before I leave the company compound, Karl and I eat frozen yogurt and drink coffee at the SpaceX café. I ask him what he would say to those who argue that government money devoted to space exploration would be better spent on social programs. He argues that space exploration may not have any kind of immediate social impact, but it is a creative endeavor, akin to music and dance. Arguing to eliminate space exploration would also eliminate anything non-utilitarian, such as art museums and concerts. Exploring the unknown and building rockets, cars, ships, computers, pottery, and musical instruments is somehow an inevitable aspect of being human, he says. All creative endeavors must be supported as much as possible, as they support our human-ness. 

Works Cited:

Andersen, Ross. 2015. “Elon Musk Puts His Case for a Multi-Planet Civilisation” Aeon Essays. Accessed November 21. https://aeon.co/essays/elon-musk-puts-his-case-for-a-multi-planet-civilisation.

Bennett, Jane. 2010. Vibrant Matter: A Political Ecology of Things. Durham and London: Duke University Press.

“Company | SpaceX.” 2016. Accessed April 18. http://www.spacex.com/about.

Ellman, Rachel. 2014. “Skeletal Adaptation to Reduced Mechanical Loading.” Dissertation, Cambridge, MA: Massachusetts Institute of Technology.

———. 2015. Personal Interview. Hawthorne, CA. November 15, 2015.

Kosek, Jake. 2006. Understories: The Political Life of Forests in Northern New Mexico. Durham and London: Duke University Press.

Robbins, Paul. 2012. Political Ecology. 2nd ed. Chichester, UK: John Wiley and Song, Ltd.

Robinson, Kim Stanley. 1993. Red Mars. New York: Bantam Books.

———. 1994. Green Mars. New York: Bantam Books.

———. 1997. Blue Mars. New York: Bantam Books.

Starr, Susan Leigh. 1999. “The Ethnography of Infrastructure.” American Behavioral Scientist 43 (3): 377–91.