1. Introduction

Current planning for the first expedition to Mars envisions a mission duration of between two and three years and a crew of six or seven people (Kanas & Manzey, 2008). Being confined with the same individuals for such a long period of time millions of miles from Earth might create psychological and interpersonal stress for the crewmembers and affect their ability to carry out mission goals. People have been on-orbit for as long as 14 months with no apparent negative sequelae, but this duration was relatively brief compared to a Mars mission, the crew had real-time contact with mission control and family and friends on the ground, and the Earth was always in sight. Nevertheless, to fully appreciate the psychosocial and psychiatric issues affecting a Mars crew, it is important to begin by examining the on-orbit experience.

2. Near-Earth Space Missions: What Do We Know?

Kanas and his colleagues conducted two international NASA-funded studies of psychological and interpersonal issues affecting crewmembers and mission control personnel during on-orbit missions to the Mir and the International Space Stations (Kanas et al., 2000, 2001b, 2007; Boyd et al., 2009). Four areas were examined: possible changes in emotional state and group social climate over time, displacement of tension to personnel outside of the group, American and Russian cultural differences, and the task versus support roles of the leader. The Mir study sample involved American astronauts, 8 Russian cosmonauts, and 42 American and 16 Russian mission control personnel. The ISS study sample involved 8 American astronauts, 9 Russian cosmonauts, and 108 American and 20 Russian mission control personnel. Subjects completed a weekly study questionnaire that included items from the Profile of Mood States, the Group Environment Scale, the Work Environment Scale, and a Critical Incident Log.

The findings from the two studies were similar. There were no significant changes in levels of mood and group interpersonal climate over time, and no evidence for the so-called “3rd quarter phenomenon”, where mood and cohesion levels are thought to worsen after the halfway point of a mission involving isolated individuals (Kanas & Manzey, 2008). However, both studies found evidence for the displacement of negative emotions in the group to outsiders, with the effect being stronger for the isolated crewmembers than the mission control subjects. Crewmembers scored lower on a number of negative dysphoric mood subscales than ground personnel, but both of these groups scored lower than normative samples of people who worked in non-space related jobs on Earth. In both studies, the support role of the leader was positively related to group cohesion among crewmembers, and both the task and support roles of the leader were positively related to cohesion among mission control personnel. Crewmembers scored higher in cultural sophistication than mission control personnel, and Russians reported greater language flexibility than Americans. Americans scored higher on a measure of work pressure than Russians. For the crewmembers, the astronauts scored one standard deviation above published norms on this measure, whereas the cosmonauts scored below the norm. Both national and organizational factors were implicated in accounting for this difference (Boyd et al., 2009).

Other investigators have studied similar phenomena. Gushin et al. (1997, 2003) found that space crews and other isolated groups showed decreases in the scope and content of their communications and a tendency to filter what they said to outside personnel, which the research team called “psychological closing”. Crewmembers also interacted more with some individuals than others in mission control, which was felt to be due to a process of “autonomization”, where isolated crewmembers become more egocentric and perceive some outsiders as opponents. Tomi et al. (2007) surveyed 75 astronauts and cosmonauts and 106 mission control personnel in order to assess intercultural issues that could lead to conflict during space missions. Both crew and ground subjects rated coordination problems between space organizations involved with the missions as the biggest problem, followed by communication difficulties due to simple misunderstandings. Other difficulties related to differences in language and work management styles and communication problems between mission control personnel and their support teams. Nechaev et al. (2007) surveyed 11 cosmonauts in order to gain information on human factors issues during an expedition to Mars. Factors seen as potentially causing psychological problems included isolation and monotony, communication delays with the Earth due to the long distances involved, leadership issues, differences in management style among the involved space agencies, and cultural problems related to the international makeup of the crew. Finally, Sandal and Manzey (2009) conducted a survey of 576 employees of the European Space Agency in order to assess important cultural issues that could impact on performance. They found a link between cultural diversity and human interaction challenges that could interfere with efficiency. Especially important were factors related to leadership issues and decision-making processes.

A number of psychiatric problems have been reported from on-orbit space missions (Kanas & Manzey, 2008). Most common are adjustment reactions to the novelty of space, which present with emotional symptoms like anxiety or depression. For example, one astronaut beginning an on-orbit space mission became depressed due to the isolation he felt and his separation from his wife and family. These symptoms resolved as he adjusted to his new environment. Psychosomatic reactions also have been reported from space, which consist of physical symptoms that suggest the presence of a medical condition but which are not fully explained by a real physical problem. For example, an on-orbit cosmonaut wrote in his diary that he experienced tooth pain following some anxious dreams he had of a tooth infection and his concern that nothing could be done about such an infection should it occur in space.

Problems related to major mood and thought disorders (e.g., manic-depression, schizophrenia), which have genetic or familial determinants, have not been reported during space missions, probably because potential space travelers are screened psychiatrically for predispositions to these psychotic conditions. However, these syndromes have been reported in astronaut applicants, as well as up to 5% of people working in space analog environments, such as submarines and Antarctic bases (Kanas & Manzey, 2008). Due to their potential for causing major individual and crew disruptions, as well as the inability to evacuate a psychotic or suicidal person who is millions of miles away from the Earth, careful attention needs to be given to the prevention and treatment of these serious mental illnesses during a long-distance space mission.

Post-mission personality changes and psychiatric problems have affected returning space travelers and have included depression, anxiety, alcohol abuse, and marital readjustment problems that have necessitated psychotherapy and psychoactive medications. Both peer-led support groups and professional interventions have been offered to family members of astronauts engaged in space missions. On a long and highly visible expeditionary mission, such as a trip to Mars, even more attention needs to be given to affected families as well as to the returning space travelers.

Asthenia is another important condition that afflicts people in space (Kanas & Manzey, 2008; Kanas et al., 2001a). The symptoms of this syndrome may include fatigue, irritability, emotional lability, attention and concentration difficulties, restlessness, heightened perceptual sensitivity, heart palpitations and blood pressure instability, and sleep and appetite problems. Russian psychologists and flight surgeons have viewed asthenia as a major adaptation issue that affects most cosmonauts participating in long-duration space missions. Consequently, a number of countermeasures have been developed to deal with it, such as increasing the frequency of communication between space travelers and family members on Earth and sending up surprise presents and favorite foods on resupply ships to improve morale. Although there is some evidence that asthenia is a culturally-specific syndrome (Ritsher et al., 2007), more research needs to be done evaluating its clinical characteristics and its frequency during space missions.

Isolated and confined environments can also be positive as well as negative. Ihle et al. (2006) conducted a study involving 39 astronauts and cosmonauts who had participated in at least one space mission and completed a Positive Effects of Being in Space questionnaire. All of the respondents reported at least some positive change as a result of flying in space. The items studied clustered into eight subscale categories: Perceptions of Earth, Perceptions of Space, New Possibilities, Appreciation of Life, Personal Strength, Changes in Daily Life, Relating to Others, and Spiritual Change. Of these, only one was significantly different from the others: Perceptions of Earth. One of the items in this subscale, “I gained a stronger appreciation of the Earth’s beauty”, had the highest mean change score, suggesting that it resulted in a “great degree” of positive change in the space travelers. Respondents clustered into two groups based on the intensity of their reported changes, possibly reflecting differences in personality or cognitive styles (e.g., reactivity versus relative insensitivity to experiences or differences in emotional expressiveness). Extending pioneering work begun in the early 1990s on the salutogenic (i.e., growth-enhancing) aspects of space travel, Suedfeld and his colleagues (2010) conducted a thematic content analysis on the published memoirs of 125 space travelers. They found that after returning from space, their subjects scored higher in Universalism (i.e., greater appreciation for other people and nature), Spirituality, and Power (especially social recognition). Russian cosmonauts scored significantly higher in Achievement and Universalism and lower in Enjoyment than U.S. astronauts. Taken together, the Ihle and Suedfeld studies suggest that traveling in space can be salutogenic for many of its participants and that personality or cultural factors may play a role in how this is manifested.

3. Expedition to Mars: Impact on the Human Psyche

Although the above findings have relevance for future on-orbit and lunar missions, caution must be used in extrapolating them to missions beyond the Earth’s neighborhood, such as an expedition to Mars. Unprecedented factors will affect such a mission. A Mars crew will be tens of millions of miles away from home, engaged in a mission that will last around 21/2 years. Crew members will experience a severe sense of isolation and separation from the Earth, which will appear as a receding bluish-green dot in the heavens. From the surface of Mars, there will be 2-way communication delays with the Earth of up to 44 minutes, depending on where the two planets are located in their respective orbits, and the crew will be relatively autonomous from mission control.

These stressors have a number of psychological, interpersonal, and psychiatric implications (see Table 1). Not everyone in the astronaut corps will want to be away from family and friends back home, isolated with the same individuals for such a long period of time. This may have ramifications for the selection process. What kind of people would be selected for the crew, and how compatible will they be? Also, the psychological (and physical) impact of long-term microgravity and high radiation in deep space, plus the 38%-Earth gravity on Mars, has not been studied previously. On current near-Earth space missions, a number of interventions can be implemented to support crewmember psychological well-being, including real-time family conferences and consultations with mission control, and the sending of morale-enhancing gifts and favorite foods on resupply ships. Such actions to counter the effects of isolation will not be available to a crew on Mars. The unprecedented autonomy experienced by the crew will make them highly dependent upon local resources, such as on-board computers and chemical facilities that will provide basic life-support and ability to produce food, water, and fuel from the Martian atmosphere. There will be limited social contact and interpersonal novelty during the course of the mission. There also will be a great deal of leisure time (especially during the outbound and return flight phases of the mission), and occupying it meaningfully and with enough flexibility to accommodate changing tastes may be difficult. There will be an increased risk of medical and psychiatric illness during such a long mission, as well as an increased chance of accidents while exploring the surface of Mars. The crew will need to have ample training and resources to deal with potentially life-threatening situations since there will be no way to evacuate an ill individual back home. Finally, no human being has ever seen the Earth as an insignificant dot in the vast heavens. As mentioned above, gazing at the Earth has been rated as the major positive factor of being in space (Ihle et al., 2006), and the experience of this “Earth-out-of-view “ phenomenon on crewmember psychology may result in increased feelings of isolation, homesickness, dysphoria, or even suicidal or psychotic thinking.

4. Coping with a Mars Expedition

Based on current knowledge, there are several countermeasures that can be implemented to help ameliorate the impact of the above issues on the crew of a Mars expedition. Crewmembers can be selected to include people who are psychologically-minded and are equally comfortable working alone on a project when necessary as well as interacting with their teammates and valuing teamwork in general. Commanders should be selected who have a history of using both task and support leadership characteristics in accordance with the needs of their team. They also should be sensitive to the impact of psychological and cultural factors on individual and crew behavior.

Pre-launch, crewmembers and mission control personnel should receive psychosocial education training aimed at recognizing and dealing with important psychological and interpersonal issues. Some of this training needs to be done conjointly with the crew and key members of the mission control staff. Important topic areas include ways to work and interact productively under isolated and confined conditions, recognizing and dealing with potential intrapsychic and interpersonal problems, and coping with increased autonomy and dependence on local resources.

During the mission itself, crewmembers and mission control personnel should receive computer-based psychosocial education training refresher courses to remind them of key issues discussed prior to launch. Crews should plan time for “bull sessions” to discuss personal and interpersonal issues and stresses before they fester and become problematic. Strategies need to be developed to allow crewmembers to communicate efficiently with people on Earth during time-delayed conditions (e.g., writing e-mail messages that include suggested responses at the end to which the recipient may reply without the need for repeated back-and-forth communications). An on-board telescope with which to see the Earth in real time may help the crewmembers deal with feelings around separation from their home planet.

Families at home need to be supported during the mission, using both informal (peer-led groups) and formal (counseling with a therapist) activities. Post-return readaptation debriefings and supportive activities need to be employed to help both the returning astronauts and their families to readjust to life on Earth together and to deal with the fame and glory resulting from a highly-visible space expedition. The first mission to Mars will be a major human accomplishment, with important psychological ramifications for everyone involved, including the general public.

Acknowledgment:

The research described in this paper was supported by National Aeronautics and Space Administration contracts #NAS9-98093 and #NCC-0161.