Space missions planned in the coming decades to the Moon and Mars and possibly asteroids are becoming increasingly distant and long. When these missions are manned, it is logical to expect an increase in the already-known psychophysiological problems of astronauts and the possible emergence of new ones. Therefore, the topic of adaptation to the conditions of a long stay in outer space is being seriously studied by experts. For example, these issues are covered in the 2023 paper Human behavior and performance in deep space exploration: next challenges and research gaps.
Studies have shown that there is a link between psychological problems caused by different lengths of time in space and physiological problems that may arise as a result. Conversely, physiological problems or lack of physical activity can cause emotional imbalance, depression, and other psychological problems. Therefore, it is better to consider them in combination.
Is staying on the ISS a “rehearsal” for interplanetary flights?
Many factors can lead to psychological discomfort and, over time, to more serious sleep problems, anxiety, and even depression. These include a closed room of limited size, lack of sunlight, a small team of permanent employees, and monotony in work and leisure. Let’s not forget about the tension due to possible threats from outer space (micrometeorites, solar flares, sudden increase in radiation background, etc.) and emergencies at the station itself. A long flight can lead to feelings of boredom, insecurity, loneliness in outer space, and the realization that you cannot get help from the outside in case of a critical situation.
Of course, before flights, crew members are necessarily prepared for such tests, but during a space mission, the effects of stress factors only accumulate. And the first thing astronauts go through is getting used to an alien environment. According to post-psychiatric examinations, astronauts often show anxiety or depression in the process of adapting to the new conditions of existence in space, although there are no severe psychological consequences.
To assess the possible psychological consequences of a long flight (at least several months in a row), we can refer to the experience of astronauts from different countries on the International Space Station, analyzing the body’s reactions to certain restrictions and unusual conditions. The ISS orbits the Earth at a distance of about 400 km above the surface, making 15.5 revolutions per day, lasting 92 minutes, meaning that astronauts watch the sunrise and sunset 16 times “a day”. This is hardly easy to get used to. In this limited space, about 73 m long and 109 m wide, several people live together for some time – resting, conducting various studies, astronomical observations, station maintenance, etc.
Staying on the ISS can already be seen as preparation for a long interplanetary flight: it includes teamwork in a small team, spacewalks for repair work, and gaining experience in managing and maintaining the station. All of this increases professionalism, self-confidence, and the success of the mission and creates a positive attitude among astronauts. Working in the greenhouse on board the orbital complex allows them not only to conduct biological experiments in microgravity, growing crops for their consumption, but also to enjoy communicating with plants, relieve psychological stress, and improve their general condition.
Psychological problems should be complemented by physiological ones, as certain processes in the organisms of living beings in zero gravity occur differently than on the Earth’s surface. Sleep has the best effect on a person’s general condition, mood, and performance. In orbit, however, sleep can be a problem. Due to the frequent alternation of sunrises and sunsets, the astronauts’ circadian rhythm is lost, and the station’s equipment operates around the clock, creating a constant noise background. In general, it is difficult to get used to sleeping in zero gravity when you have to fasten yourself to the bed with belts, so crew members have to take sleeping pills.
And if we’re talking about future long-duration flights, for example, to Mars (at least seven months one way), we need to take into account the impact of solar radiation on the human body. This impact is quite significant even during periods of minimum solar activity. Radiation and extreme gravitational conditions are the main hazards during space travel. The consequences of exposure to a constant radiation background can include damage to immune function, cellular aging, and cognitive impairment. The effect of microgravity inside the spacecraft and zero gravity in outer space is physiologically unfavorable for internal organs (lungs, kidneys), cardiovascular system, and sensory organs. Microgravity alters the circulation of body fluids, kidney excretion, blood pressure, and lung capacity and increases the frequency of cardiac arrhythmias. It also causes a rather rapid aging of the immune system.
According to the results of medical research on the effects suffered by astronauts, the most serious are problems with bones and muscles, vision, and blood vessels. For example, the vessels leading to the brain become stiffer under the influence of microgravity. That’s why, as you know, astronauts cannot get out of their capsules on their own after returning to Earth – they need help. The same will happen on Mars after landing, but there will be no one to help.
From theory to experiments: how do they prepare for Martian conditions?
Staying in space for any length of time requires astronauts to have not only high professional qualities but also good physical and psychological training, communication skills, and knowledge of human behavior in an isolated team. That is why people are trained in advance on the ground to take into account all possible mistakes and avoid repeating them during a long flight or upon arrival at their destination.
In particular, potential astronauts for future missions to Mars are trained in desert conditions (or people are tested for the possibility of becoming them), as they are as close as possible to the conditions on the surface of the Red Planet. These can be short-term training sessions of 3-4 weeks. They can also last up to a year to study the effects of long-term isolation.
In 2021, an experiment was conducted in the Ramon Crater in southern Israel with a team of specialists from different countries – five men and one woman. For three weeks in a row, people stayed in a 120 m2 residential module, simulating living inside an analog of a future Martian research station. The participants of the experiment were constantly under video surveillance, and their condition was monitored.
Source: AFP via Getty Images
The Martian Research Station in the San Rafael Desert (Utah, USA) is headed by Ukrainian engineer Serhii Yakymov. The station has been operating since the early 2000s and hosts groups of enthusiasts from all over the world. Their main tasks are simulations of expeditions on the surface of Mars, social, biological, and geological research, and testing of engineering equipment. The research teams stay there for several weeks, live in special modules, work in greenhouses, and go outside only in spacesuits.
There is still much research to be done until the technical level of future spacecraft allows the first space mission to be safely sent into long-distance flight. The experience of people in space during and after missions should continue to be studied, which will help to understand the psychological consequences of a much longer space journey. It is also necessary to develop, test, and improve adaptation methods and all possible measures to preserve people’s mental and physical health.
For those who are deeply interested in the topic of the article, we recommend the book Psychology of Space Exploration, edited by Douglas A. Vakoch (The NASA History Series 2011), which contains many references to publications by other authors on this topic.
Author: Yuliana Kuznietsova, researcher at the Main Astronomical Observatory of the National Academy of Sciences of Ukraine
This article was published in Universe Space Tech magazine #1 (190) 2024. You can buy this issue in electronic or paper versions in our store.
