Space Issues: What Does Space Do To Human Body?

As a cradle for life, Earth possesses numerous qualities that we sometimes don’t fully grasp while residing within its protective embrace. Simply dispatching probes and rovers to the moon and Mars won’t suffice. Due to various motivations, such as the pursuit of adventure, preparedness for potential disasters, and economic interests, we are determined to extend our physical presence beyond our home planet. Several private enterprises have even unveiled intentions to establish space hotels soon. NASA plans to use 3-D printing to create lunar neighborhoods in the next few decades. While the prospect of creating and populating an outpost on Mars may require an extended timeline, we are actively engaged in preparatory efforts. A significant milestone in this endeavor occurred this past summer when four NASA crew members embarked on a 378-day mission, inhabiting a simulated Martian habitat at the Johnson Space Center in Houston, marking a substantial stride toward interplanetary exploration.

As you gaze upon the illustrations of these inviting abodes, it’s effortless to overlook the harshness of space for inhabitants from Earth. To reiterate, take a moment to contemplate the dire consequences of being in low Earth orbit, on Mars, or on the moon without the protective confines of a spacesuit. Within mere seconds, you would succumb to hypoxia, a state of oxygen deprivation, and shortly after that, your life would come to an end. During this brief interim, the gases contained within your body, including any remaining air in your lungs, would undergo expansion due to the absence of external pressure. This depressurization would also transform your internal fluids into a gaseous form. It’s important to note that an increase in temperature does not drive this process but rather represents a transition to their gaseous state.

Temperature wouldn’t pose a significant issue. Thermometers in low Earth orbit record temperatures ranging from minus 85 degrees to 257 degrees Fahrenheit, depending on whether they are in shadow or exposed to light. Being a near vacuum, space lacks sufficient mass for effective heat conduction toward or away from your body. Consequently, you wouldn’t experience immediate sensations of extreme heat or cold.

Hypoxia is a potential threat in a breach in your space vessel or extraterrestrial habitat. Still, it is a challenge that can be managed (provided you have yet to decide to take a daring leap out of your space capsule or off-world dwelling). However, there are two other significant challenges that our delicate bodies encounter when departing from Earth, and neither of these challenges has been completely overcome, even within indoor environments. These challenges are variable gravity and radiation.

Gravity is determined by the mass of objects and the distance separating them. Due to Earth’s substantial size, evading its gravitational pull for extended periods while on the planet’s surface is practically impossible. Consequently, we have limited knowledge of life without this ubiquitous force or under the influence of reduced gravity. On the moon and Mars, which are significantly smaller than Earth, the gravitational force is considerably weaker, measuring approximately one-sixth and one-third of Earth’s gravity, respectively.

In contrast, as you ascend in elevation, radiation exposure becomes more intense due to the reduced atmosphere above you, which provides less shielding. Suppose you venture beyond the protective shield of Earth’s ozone and magnetosphere, a magnetic field extending approximately 40,000 miles at its most compressed region. In that case, you will be exposed to significantly higher radiation levels. When considering Mars, which is at its closest, around 34 million miles away, the potential radiation exposure from solar and galactic sources could be as much as 700 times greater than what penetrates through our magnetic defenses on Earth. Space explorers venturing beyond low Earth orbit will also be exposed to high-energy atomic nuclei originating from supernovae and other exploding stars scattered throughout the galaxy. Typically, Earth’s magnetosphere deflects these particles, preventing them from reaching our planet’s surface. However, these particles, characterized by their substantial weight and rapid velocity, can penetrate spaceships, spacesuits, and even human skin. As they collide with other particles along their trajectory, they can cause damage to cells in various ways, a phenomenon that researchers are still in the early stages of comprehending.

Until now, most of our understanding regarding the impact of these hazards on the human body has been derived from astronauts stationed in low Earth orbit. Due to the paramount importance of safety, we have limited the number of astronauts sent to this region, and their stays have been relatively brief. Typically, missions to the International Space Station, located 250 miles above Earth’s surface, last approximately six months. A maximum of 300 individuals have embarked on this journey to the space station.

Although the knowledge gained from this collective experience has provided valuable insights into how the human body adapts to reduced gravity, it’s important to note that the International Space Station (I.S.S.) continues to benefit from the protection of Earth’s magnetosphere. Additionally, only the 24 astronauts who participated in the Apollo program have ventured beyond this protective shield. (The moon, on average, orbits at a distance exceeding 238,000 miles from Earth.) Even though these 24 astronauts spent relatively brief periods without the protective shield of Earth’s magnetosphere, their mortality rate due to cardiovascular disease is four to five times higher than that of their counterparts who remained in low Earth orbit or never ventured into space. This disparity hints at the possibility that exposure to cosmic radiation could have harmed their arteries, veins, and capillaries.

Ensuring the survival of individuals traveling to Mars or living on the moon is a prerequisite before such missions can be undertaken. However, the progress of space-based medical research aimed at achieving this goal has been impeded by the limited size of the study groups, which are not representative of the broader population. Notably, all Apollo astronauts were white men born between 1928 and 1936. Nevertheless, the emerging field of space tourism holds the promise of enabling the study of radiation and low-gravity effects on a much more diverse demographic than what has historically been referred to as “highly selected superhuman individuals,” a term used by Dorit Donoviel, the director of the Translational Research Institute for Space Health (T.R.I.S.H.) at Baylor College of Medicine. Dorit Donoviel, the director of the Translational Research Institute for Space Health (T.R.I.S.H.) at Baylor College of Medicine, emphasized the importance of studying a diverse range of individuals, including those of varying ages and with pre-existing health conditions, as this will build a knowledge base crucial for both NASA and the future of space exploration. According to Donoviel, understanding how our bodies adapt to hostile environments requires insights from studying individuals facing health challenges. Through the experiences of those who become ill, we gain a deeper understanding of the mechanisms of illness and how to prevent it.

Epidemiologists encounter a similar challenge on Earth: They must wait for a sufficient number of people to be affected by a particular issue before they can identify its causes and develop protective measures. With the relaxation of strict medical screening for space tourists, the likelihood of individuals experiencing injuries or health emergencies in space rises considerably. Aerospace medicine is among the three specialties recognized by the American Board of Preventive Medicine. This is because doctors preparing for a space mission must focus on ensuring the well-being of their patients and preventing potential crises before the journey begins. Consequently, like any venture into uncharted territory, there will come a time when courageous or determined individuals will have to leap into space to gain firsthand experience.

In the past, scientists had predicted that human life would be unsustainable without the presence of Earth’s gravity. The absence of this force, which we still don’t fully comprehend, raised questions about our basic bodily functions. How would we be able to swallow? Wouldn’t our tongues fall back into our throats, potentially leading to choking on our saliva? Moreover, it was theorized that increasing pressure within our skulls might prove fatal after about a week in such conditions. However, Yuri Gagarin’s return from his historic 108-minute orbit around the Earth in 1961, marking humanity’s first foray beyond the mesosphere, provided concrete evidence to the contrary. He demonstrated that our internal musculature can maintain our essential functions even in a weightless environment. During his mission, Gagarin could eat and drink without difficulty, dispelling the earlier concerns. From a technical perspective, Yuri Gagarin had yet to break free from Earth’s gravitational influence completely. Instead, he was in a state known as microgravity, which involves constantly falling toward the Earth without ever making contact with it. In this condition, he described the sensation as feeling like he was suspended horizontally by belts, somewhat akin to the experience one might have on a roller coaster or when leaping off a diving board. Gagarin mentioned that he eventually became accustomed to this feeling, remarking that no negative sensations were associated with it.

Either Gagarin was not entirely truthful, or he possessed a robust stomach. In the beginning, many space travelers experience nausea, motion sickness, or what is known as space-adaptation syndrome (S.A.S.), characterized by symptoms like headache and vomiting when outside Earth’s atmosphere. Jan Stepanek, the director of the aerospace-medicine program at the Mayo Clinic in Scottsdale, Arizona, explains it as a sensation similar to the one you might have had as a child when reading something with your head down in the back of a car. It results from a disparity between what your eyes perceive and the signals your inner ear sends to your brain. In this situation, the discord between perceptions arises because the organs and hair cells of the vestibular system are deprived of their typical gravitational cues. However, with time, individuals do adapt to this condition. Interestingly, it was only in the 1970s that researchers became aware of the prevalence of S.A.S. symptoms when they overheard Skylab astronauts discussing them over an open microphone. Astronauts are not ideal candidates for medical research because they are exceptionally resilient and hesitant to report any symptoms that might prevent them from going on missions.

On Earth, your body regulates blood pressure to ensure that your organs receive an adequate oxygen supply and that waste products are efficiently removed. A major oxygen consumer, your brain, is typically located above your heart while awake. However, in microgravity, the force that usually pulls blood downward into your legs, like when you lie down or enter a pool, ceases to operate, and this effect is even more pronounced. This causes blood to accumulate in the upper part of your body, activating pressure sensors in your heart and the carotid vessels in your neck. These sensors then send signals to increase urine production and reduce blood production. (This is similar to the sensation of urinating after lying down or immersing oneself in water.) On Earth, this process typically helps lower blood pressure and restore equilibrium in your body.

In a microgravity environment, the blood volume in the upper part of your body is likely to remain too high, at least temporarily. This can impact the eyes and optic nerves, potentially leading to permanent vision issues for astronauts spending extended periods in space. This condition is known as spaceflight-associated neuro-ocular syndrome. This condition also leads to fluid buildup in the surrounding tissues, resulting in facial puffiness and sinus congestion. Similar to the effects of a severe cold, this process dulls the nerve endings in the nasal passages, reducing the ability to smell or taste effectively. (The nose significantly contributes to the sense of taste.) As a result, the galley on the International Space Station (I.S.S.) often includes items like wasabi and hot sauce to enhance the dining experience.

These sensory impairments can serve a purpose in specific ways, given that the International Space Station (I.S.S.) often has unpleasant odors like body odor or flatulence. Due to the lack of showers and the effects of microgravity, digestive gases can’t quickly rise out of the mixture of bodily fluids in your stomach and intestines, making it challenging to burp without the risk of vomiting. Since the gas needs to exit the body somehow, flatulence’s frequency and intensity (measured in volume and noise level) tend to rise.

Other metabolic processes are also disrupted. Urine doesn’t accumulate at the base of the bladder as it typically does, where the increasing liquid pressure above the urethra typically signals when the bladder is two-thirds full. Consequently, the bladder can reach its maximum capacity before any urge to urinate is sensed, potentially leading to sudden and spontaneous urination, as stated in “A Review of Challenges & Opportunities: Variable and Partial Gravity for Human Habitats in L.E.O.,” which refers to low Earth orbit. This report, authored by Ronke Olabisi, an associate professor of biomedical engineering at the University of California, Irvine, and Mae Jemison, a retired NASA astronaut, was published last year. Occasionally, the bladder fills but fails to empty, requiring astronauts to perform self-catheterization.

The longer astronauts spend in microgravity, the more their bodies change. Without the need to support any weight, their bones and muscles start to deteriorate, which happens much more rapidly than the natural aging process on Earth. In space, bone density in areas like the hips and spine can decrease by 1 to 2 percent each month, whereas elderly individuals on Earth experience a decrease of 0.5 to 1 percent yearly. The calcium released from the bones is excreted in urine, which raises the likelihood of kidney stone formation. Additionally, muscle mass diminishes over time. Astronauts must exercise for over two hours daily to maintain a reasonable fitness level. During these workouts, they must frequently wipe their skin with a towel to prevent sweat from forming droplets that might float into their colleagues or equipment. Additionally, the discs between their spinal vertebrae widen, causing astronauts to grow taller and leading to lower back discomfort. The body’s mechanisms that, on Earth, increase our blood pressure when we transition from lying to standing up to prevent us from fainting gradually deteriorate in the absence of regular use. This decline, coupled with the loss of muscle mass, is why astronauts must be assisted when exiting their capsules upon returning to solid ground following an extended mission.

The body readjusts to its normal state over time. However, extended periods in microgravity, such as the current record of 437 days set by Russian astronaut Valeri Polyakov in 1995, result in challenging and painful recoveries. Following his 340-day stay in space, NASA veteran Scott Kelly, who had previously undertaken three shorter missions, described the period immediately after his return as more challenging than his earlier trips. In his 2017 memoir “Endurance,” he noted, “All of my joints and all of my muscles are protesting the crushing pressure of gravity.” (Legend has it that Valeri Polyakov, after his lengthy mission, calmly walked out of his capsule, asked a friend for a cigarette, and started smoking.) In any case, “recovery” in this context always involves readjusting to Earth’s gravitational pull. However, what if you never return and, instead, opt to spend the remainder of your life in orbit on the moon or Mars?

When you spin a bucket of water around your head at a sufficient speed, the water stays inside without spilling. This same principle serves as the foundation for most concepts aimed at creating what is commonly referred to as artificial gravity. In these scenarios, astronauts become akin to the water in the bucket. However, the challenge is that the rotational speed must increase as they approach the axis. You have two options: a large spacecraft with slow rotation or a small one with a rapid cycle. So far, government agencies still need to prioritize the engineering and transportation of such a device into low Earth orbit. Providing astronauts with tools to manage weightlessness is much simpler and more cost-effective.

However, the fact that NASA still needs to employ rotating spacecraft to create gravity simulations doesn’t rule out the possibility, according to Rhonda Stevenson, the C.E.O. of Above Space. Her company intends to launch a small luxury hotel into orbit within the next five years and establish a larger facility within another decade once it secures the required funding. These accommodations resemble large gear structures with rooms within their cogs in conceptual designs. “People often underestimate our current technological capabilities and where we stand today,” she explained.

Stevenson’s goals and those of fellow space tourism providers prioritize enjoyment and comfort over endurance and scientific pursuits. While astronauts typically refrain from voicing complaints, paying guests are more inclined to express dissatisfaction, mainly when investing millions for a weekend getaway. Consequently, it is essential to provide modern amenities, including flush toilets, which have evolved with consideration for the effects of gravity. As Stevenson points out, “No one desires to journey into space only to feel isolated, consume algae-based food, and dine on crickets. That doesn’t sound like an appealing experience.”

In due course, affluent tourists seek destinations and amenities for their space vacations, such as space malls or miniature golf courses. They will also desire a diverse selection of culinary options. Stevenson and her contemporaries anticipate the development of commercial parks, factories, and farms in space to cater to the needs and desires of these travelers.

The space industry is one of many sectors with ambitions related to space. Chemistry and drug discovery stand to benefit, as crystals, including those used in pharmaceuticals, tend to grow larger and more symmetrically in microgravity. There are plans to extract rare metals from the moon. Solar energy production could thrive without the interference of weather conditions. Additionally, astrobotany, which is crucial for providing fresh food to space settlements, could lead to the growth of crops that could even be sent back to Earth. In one experiment, wheat plants exhibited 10 percent greater height growth in microgravity.

When that time arrives, whether you’re in space for work or leisure, fine-tuning your gravity experience could become as routine as adjusting your thermostat. Your workday might involve microgravity, followed by a jog or relaxation in a 1 g environment. As you age and experience joint discomfort, you could opt for rooms set at 0.75 g, providing just the right amount of gravity to rejuvenate your mobility. Imagine seniors living – in space!

While supplying gravity as envisioned might prove challenging, experiencing weightlessness would generally be inconvenient for a few hours to reach low Earth orbit or a few days during a flight to the moon. However, the journey to Mars and back will likely involve living in microgravity for over a year, raising physical concerns. Questions arise about whether these astronauts can stand upon arrival, the risk of passing out, potential bone fractures, and the healing process of fractures in a microgravity environment compared to Earth.

Researchers have limited understanding regarding astronauts’ neurological conditions and whether cognitive functions are influenced by the pressure exerted on the brain due to fluid shifts towards the head in microgravity. According to Donoviel, very few NASA astronauts are willing to volunteer for experiments involving the insertion of needles into their brains or eyes to measure pressure while in space due to the associated risks. There is a concern that such experiments might reveal medical issues that could disqualify them from future flights. This experiment has been planned for a while but has yet to be carried out.

Researchers are optimistic that individuals traveling on commercial spaceflights may be more willing to participate in experiments, such as undergoing a surgical procedure to implant a novel pressure transducer into their skulls several months before their space journey. If the device performs as anticipated, it could provide valuable insights into the effects of microgravity on the brain. Additionally, this research may offer potential benefits in treating infants with hydrocephalus, a neurological condition resulting from the accumulation of cerebrospinal fluid in the brain’s deep ventricles, benefiting both parents and healthcare professionals.

Shortly, it may be possible to conduct similar experiments using stem cells derived from an astronaut’s blood to cultivate mini organs. These mini-organs can then be subjected to elevated levels of radiation or microgravity in space, providing insights into how the astronaut’s real organs would respond to the conditions of living off-world. Gordana Vunjak-Novakovic, a professor of biomedical engineering and medical sciences at Columbia University, explained that the concept revolves around each astronaut contributing a small volume of blood, which would be used to create a personalized research platform for individual astronauts.

Scott Kelly’s time in space has resulted in subtle yet potentially significant physiological changes. He suffered a minor amount of D.N.A. damage, believed to be a result of radiation exposure. (Astronauts’ radiation exposure levels are closely monitored over their lifetimes, and if these levels become too high, they may be disqualified from future space missions.) Additionally, he underwent epigenetic modifications, which alter how genes are expressed and can be inherited. This mechanism allows humans and other organisms to preserve advantageous adaptations without relying solely on the slow process of natural evolution. These changes, which mostly returned to their baseline state following Kelly’s return to Earth, provided researchers with insights into which genes might be most affected by prolonged stays in space.

One of the most perplexing observations made by researchers was the alteration in Scott Kelly’s gut microbiome, which refers to the community of bacteria, fungi, and viruses residing in the digestive tract. While the bacterial species remained the same, their proportions relative to each other underwent significant shifts, likely due in part to differences in Kelly’s diet while in space. These changes among the microorganisms raise concerns, as they play crucial roles in digestion, metabolism, and immunity. Shifts in their composition have been linked to various neurological and physiological conditions. In the space environment, reduced immunity is particularly problematic, as microgravity appears to cause bacterial cell membranes to thicken, rendering bacteria more resistant to antibiotics and increasing their likelihood of causing severe diseases.

Indeed, there will be unexpected discoveries in space, some of which may be rather unpleasant. From the Mayo Clinic, Jan Stepanek highlights a previous assumption in which scientists believed that blood clots were highly improbable without Earth’s gravity. However, a surprising case emerged that challenged this notion. In a 2019 study, an international team of researchers revealed that the blood flow in the jugular veins of six out of 11 International Space Station (I.S.S.) crew members they observed had, by approximately Day 50 in space, either slowed significantly or reversed direction. One of the six individuals even developed a potentially life-threatening thrombosis without displaying any symptoms. Fortunately, physicians had already stocked the I.S.S. with a 40-day emergency supply of anticoagulants and other medications as a precautionary measure.

Space medicine experts are skilled at envisioning challenging scenarios. Natacha Chough, an emergency medical physician and professor of aerospace medicine at the University of Texas Medical Branch, raises an example: “Consider the possibility of someone developing appendicitis,” she suggests. “If we’re on a journey to Mars, there’s no turning back. So, do you dispatch a surgeon? But what if the surgeon is the one who develops appendicitis?” To illustrate the importance of such preparedness, she references the remarkable case of Leonid Rogozov, a 27-year-old Soviet doctor in 1961, who had to perform an appendectomy on himself at an Antarctic base he and a team of 11 others had established. Rogozov conducted the surgery relying on his sense of touch, as he found the inverted images in a mirror disorienting. Remarkably, he successfully removed the infected organ and sutured himself within two hours, with a helpful colleague taking photographs for posterity.

The University of Texas Medical Branch (U.T.M.B.) frequently sends trainees in aerospace medicine to gain experience at a research station in Antarctica. This harsh environment may require doctors to perform medical procedures they last practiced in years ago, often with limited supplies. Ronak Shah, the director of aerospace medicine at U.T.M.B., frames the challenge by asking, “Do you have the necessary tools and support staff to carry out those procedures?” He then alludes to the popular T.V. show “Star Trek” and the character Dr. McCoy, saying, “People often imagine having a surgical suite like Dr. McCoy’s.” Every item that goes on a spacecraft must justify its presence in space, considering the high cost of transporting payloads into orbit, which can exceed $10,000 per pound. While the International Space Station (I.S.S.) does have specific medical equipment like a defibrillator and a portable ultrasound, it lacks more advanced devices like C.T. scanners or M.R.I. machines.

Performing major surgery in space is a complex endeavor as it carries the risk of the patient’s internal organs floating out due to microgravity. Even administering injections in space necessitates careful planning. In contrast, Leonid Rogozov had the advantage of being able to give himself Novocain during his self-appendectomy. Dr. Natacha Chough, the flight surgeon for NASA astronauts aboard the International Space Station (I.S.S.), faced a challenging decision when the coronavirus vaccine became available. She had to determine whether to send the vaccine on a routine resupply mission. This decision required considering the astronauts’ protection upon their return to Earth, the logistical challenges of handling liquid vaccines in space, potential side effects that could render astronauts incapable of fulfilling their duties, maintaining the vaccine’s temperature requirements, and ensuring precise dosing without any wastage. It was a challenging ethical dilemma, mainly when vaccine supplies were limited on Earth. Ultimately, Chough postponed the vaccination until the astronauts returned to Earth.

It’s a common human tendency that when we encounter new and challenging environments, such as a mountaintop or an airplane bathroom, curiosity often leads us to explore the possibilities of engaging in intimate activities there. Predictably, when the first billionaires check into space hotels, they may contemplate joining the exclusive “250-Mile-High Club.” However, this poses a significant issue: guidelines for conducting medical experiments in space that address the behavior of tourists need to be established. Dorit Donoviel emphasizes that if someone wishes to engage in intimate activities or even attempt childbirth in space, there is no regulatory framework to provide appropriate guidelines. She stresses the importance of ensuring that commercial spaceflight offers opportunities for valuable scientific research. The objective is to prevent space travel from descending into chaos, where irresponsible actions could jeopardize people’s safety, generate adverse publicity, and erode public support for space exploration—an outcome that would harm the entire industry.

Should individuals traveling in space abstain from intimate activities until an official entity deems space sex to be safe? Is it conceivable that this threshold has already been crossed? With fewer than 700 individuals having journeyed to space thus far and many readily identifiable in research publications, there may be a reluctance to share information that could interest behaviorists. To put it briefly, according to Simon Dubé, a postdoctoral research fellow at the Kinsey Institute at Indiana University, “Our understanding of astronauts’ intimacy and sexuality is quite limited.

However, we do have some fundamental knowledge. According to Dubé, “There are strong indications that erection and lubrication are not hindered in space.” Furthermore, microgravity does not seem to introduce extra side effects to contraceptives.

“If we bring Earth with us, will we disrupt the course of evolution?”

However, reproductive concerns need to be addressed if humanity is to establish permanent colonies beyond Earth. For the most part, scientists have primarily studied various aspects of reproduction in space using animals such as fruit flies, frogs, newts, geckos, aquatic crustaceans, quails, rats, mice, and even rams. While it is possible to produce and develop healthy embryos in space, it is evident that this process carries significant risks. Radiation exposure can harm D.N.A. and potentially lead to infertility and sterility in adults. Furthermore, embryos and fetuses that are exposed to radiation have a higher likelihood of experiencing growth and cognitive delays, birth defects, and increased rates of mortality among newborns.

Dubé is primarily concerned about the psychological implications of engaging in sexual activity (or the absence of it) in space. He emphasizes the challenge of experiencing the complexities of human sexuality within the confines of a small, remote, and isolated environment, with limited partners who are also colleagues crucial for your mission’s success. Drawing parallels to analogous situations, such as military basic training, past experiences have shown that such conditions can have negative consequences, particularly for women. Dubé is more concerned about the aftermath, significantly how sexual activity might impact the dynamics within the crew the following day, rather than whether individuals will be capable of having sex or engaging in self-pleasure in the space station.

The negative health consequences of solitude and seclusion in space have received limited research attention, but these effects are expected to become increasingly significant with longer mission durations. Space travel can be likened to the pandemic lockdowns experienced by many individuals in 2020, albeit with the added challenge that there’s no opportunity to open a window or go for a walk outdoors. Moreover, as astronauts venture farther from Earth, the communication delay between sending a message and its receipt by loved ones back home becomes progressively longer, potentially reaching up to 20 minutes on Mars.

In 2014, NASA released a report titled “Assessing Psychological Well-being and Performance in Isolated, Confined, and Extreme Environments.” This report drew upon data from various environments like submarines, underground bunkers, and polar expeditions. It also documented how factors such as career competition differences in personality, values, culture, and language disrupted a 105-day life simulation on the International Space Station (I.S.S.) in 1999. During this simulation, the crew resided in interconnected hyperbaric chambers, and the report described the challenges faced: “A physical altercation occurred between two crew members, a case of sexual harassment was reported, and one crew member withdrew from the study in protest,” the authors of the report noted. They further predicted that in spaceflight, where individual escape or mission termination is seldom possible, such events would pose significant risks to individual psychosocial well-being, performance, and overall mission success.

Thankfully, polar expedition teams had a somewhat more positive experience, particularly those spending the winter in Antarctica. They found several benefits in their isolation from mainstream society, including “excitement stemming from the exploration of the unfamiliar, ample free time for personal development, physical exercise, and contemplation, as well as the chance to distance themselves from the daily nuisances and negative aspects of life on Earth.”

Will those who depart from Earth feel a sense of longing for their home planet, and if they do, will they be able to return? The fact that, over billions of years, the conditions on our planet allowed simple organisms to evolve into human beings seems like a miracle. However, as Jennifer Fogarty, the Chief Scientific Officer at Baylor’s space-health institute, pointed out, we are essentially “a series of sophisticated sensors.” Our bodies are focused on conserving the energy needed for survival and quickly discarding any unused features and abilities without a second thought.

Jennifer Fogarty raises an intriguing question: “If we consider the possibility of long-term colonization, could the bodies of those who live there for extended periods evolve in a way that makes them less compatible with Earth?” This scenario might not necessarily be negative; it would indicate that they have adapted well to the moon or Mars. However, adaptation comes at a cost. Fogarty continues, “The concern would be if some of those capabilities are lost over generations. Do we bring Earth with us? Create artificial gravity? If we take Earth with us, are we going to stall evolution? Or do we let people start with an adaptive response, and maybe it’s hard for people multiple generations later to return?”

To put it differently, are we inherently bound to our Earthly origins, unable to completely shed the biological traits our home planet has bestowed upon us? Or is it conceivable that we might transform into the extraterrestrial beings we’ve often imagined? It appears that, in one manner or another, we are determined to explore this question.