by Acad. Anatoly GRIGORYEV, RAS Vice-President, research head of the RAS Institute of Medico-Biological Problems; Boris MORUKOV, Dr. Sc. (Med.), RF pilot-cosmonaut, deputy director for science of the same research institute

An auspicious experiment was completed in November of 2011 at the Research Institute of Medico-Biological Problems: it simulated a flight to Mars. Six volunteers from China, France, Italy and Russia cooped within a ground complex spent as many as 520 days and nights in complete isolation. A bounty of data was obtained, it has to be yet studied and analyzed, for it will be important for long interplanetary missions of the future. The experiment allowed to make good headway in getting to understand many aspects of their medico-biological support. What with the complexity of the task, more of the goal-oriented research is needed.

ONE STEP ALONG THE LONG PATH TO THE "RED PLANET"

Research scientists still should have it out: how deep space acts upon the human organism-a complex of factors, such as microgravitation, radiation, magnetic field variations, both on the flight path and on another planet's surface.* Interplanetary space missions will in many ways be different from orbital flights in endurance and time. Crews will have to work within a limited living space and in social isolation. They will have to show a great sense of responsibility for a success of their mission and take risks. Hence stringent selection standards.

Obviously, the experience amassed in ground research and in piloted orbital missions should be evaluated as well. No doubt, the results of the "Mars-500"**

* See: K. Trukhanov, N. Krivova, "Geomagnetic Field to Mars?", Science in Russia, No. 3, 2010.--Ed.

** See: A. Grigoryev, B. Morukov, "Mars: Ever Closer", Science in Russia, No. 1, 2011.--Ed.

experiment will be useful in planning long-distance flights and simulated missions.

The experience gained in previous experiments, including one that involved a group of volunteers in a 105-day simulated flight (March 31-July 2009), compelled us to revise the demands set on "Mars-500" volunteers. Personalistic characteristics were assessed both by standard tests and by behavioral responses within an isolated group. Coming to the fore were such traits as tolerance, a high level of motivation, an ability to concentrate on assigned tasks... A candidate had to be a creative individual capable of picking and digesting new information in different areas of activity.

Six months of preliminary control investigations and training preceded the 520-day experiment. The medical and psychological selection of candidate testers was completed in February of 2010, and their training sessions, in May 2010. The control investigations of volunteers were started in April and completed in June of 2010. The research program, including one involv-

ing the medico-technical complex, was set up between October of 2009 and May of 2010. The experiment was started at 14 h. on June 3, 2010, and finished 520 days later, at 14 h. on November 4 of 2011.

It was a tough and grueling job for prospective crew members. It meant a stiff competition, too. Anyway, it proved useful for bringing out their psychological characteristics and for picking out a tight-knit and cooperative collective which included engineer Alexei Sityov, surgeon Sukhrob Kamolov, military physician and physiologist Alexander Smoleyevsky, all three from Russia; engineers Charles Romain (France) and Diego Urbina (Italy) representing the European Space Agency, and also Wang Yue, of the Chinese Space Training Center. This crew composed of men of different nationalities and culture was an additional problem in the way of their togetherness and joint activity. Those were men of different character makeup in the 25 to 38 years age bracket. And yet they made a cohesive collective, not divided by language or nationality. They were friendly to one another and in good contact with the control group all through the 520 days of the experiment. No quarrels or spats to patch up!

The crew members were split into two groups. One had to leave the space vehicle and land on the imitation Martian surface, and the other had to stay aboard in a circular orbit. It was an emotional stress to them, for the attention of terrestrial ground services was riveted on the Martian walkers, who enjoyed a preferential status. Those in orbit gave all-out support to their comrades taking a walk below and they had to carry the double load in servicing the station. Their work done, the first group joined those on board again. They had a friendly welcome, and no psychological problems cropped up during the subsequent stretch of the experiment.

Overall, the crew carried out a big research program. They checked on their physical and psychic fitness, spending at least an hour daily exercising on the treadmill and trainers; they were also involved in other health-building activities. They monitored the habita-

Search and Development

tion parameters in their compartment (pressure, temperature, humidity and the like) and kept tabs on the food, water, materials, spare parts, life-support resources and other items used. They made scheduled prophylactic repairs in sustaining the normal performance of the modules, and carried out sanitary-hygienic tests, taking in also the results of toxicological and microbiological control.

On the first of September of 2010, that is three months after the start of the imitation flight to the Red Planet, they took charge of habitation monitoring and could issue control instructions for the complex and its systems.

We understood that an interplanetary flight, with a spaceship dozens of millions of kilometers away from the earth, would have certain constraints on on-line information because of the time lag in electron signal reception, a major handicap in communication sessions with the ground control station. Therefore voice (telephone) communication sessions were held according to the following schedule: 1-50 and 470-520 days of the experiment with no time lag. As of the 51st day speech communication sessions were on only by decision of the crew commander or surgeon for extraordinary contact with the ground services in critical situations as the health or life of any of the crew members could be in peril. Electronic messages (texts or videofiles) sent twice daily, from 10.00 to 12.00 a.m. to 16.00 to 18.00 p.m., were the main form of communication. Personal correspondence was likewise electronic, and only a systems manager from the tracking group could have access to it outside the module.

HEALTH CONDITION CONTROL

A long-distance space flight and its extreme effects on the human organism call for a great deal of effort towards sustaining a crew's health and fitness;* consequently, one of the key tasks of the "Mars-500" project was to improve the monitoring and medical aid systems. The crew medics had at their disposal an autonomous medical center supplied with adequate facilities like kits of drugs, instruments, diagnostic means, and so forth. Remote control methods, telemedical consultation among them, were also part of the support.

Every crew member had a form filled in each day in which his health condition was registered. His vital activity characteristics (arterial pressure, pulse beat, body temperature, weight, and so on) were measured twice each day. Extensive, in-depth examinations were carried out monthly to evaluate the state of the cardiovascular system (EKG, both in quiescence and under load, Holter's monitoring to check up on cardiac activity, blood pressure control). Also, blood and urine counts as well as individual psychological consultations were an essential part of the checkups. Every six months expert examinations were carried out on the

* See: O. Gazenko, A. Grigoryev, A. Yegorov, "Space Medicine: Yesterday, Today, Tomorrow", Science in Russia, Nos 3 and 4, 2006.--Ed.

condition of the organs of vision and hearing, of the oral cavity, and skin. Ultrasound was used to assess the condition of internal organs.

Body hygiene was likewise an important part of the sanitary support. Crew members could take a shower in the living compartment. Bed-clothes were changed every week, and underwear (T-shirts, shorts, socks), every three days. Every week the crew would tidy up, they vacuum-cleaned and sprayed disinfectants to keep the level of microbial dissemination within permissible limits.

Two systems of water supply were used--one for drinking and cooking, the other for sanitary and hygienic needs. The quality of the potable water was controlled according to habitation medium standards in a piloted space vehicle.

As to the food rations, they conformed to standard physiological norms for contingents whose activity, in its energy expenditures, is assigned as middle-level. Three variants were provided. The first one had a mix of 111 products, including 56 frozen semi-finished fast food items made by ten companies, nine European and one Russian. The crew had to stick to this menu, that was mandatory. The second variant taking in a stretch between 251 and 270 days of the flight, as three crewmen were to disembark and make a touch-down on the Martian surface, offered ready dishes that could be consumed without heating. Also in the menu were hot soups and beverages prepared after the model of dishes consumed by crews of the "Soyuz" space transportation craft. And finally, the third variant meant for the return journey: the three spacemen, who had stayed aboard in the circular Martian orbit, were offered dishes to eat between the 251st and 520th days of the mission; and those who had been out there on the Martian surface, were given a menu for the 271st to 520th days of the homebound flight. It comprised a list of 131 foodstuffs produced in Russia by and large. There were also Italian, Korean and Chinese national dishes. Each crewman had a choice according to his palate. The food was cooked in microwave stoves with the use of hot water.

MARTIAN LANDING PARTY

A number of operations were simulated during the experiment: takeoff, Martian landing and docking with the interplanetary complex, three walks on Mars (14, 18 and 22 February 2011) of two spacemen in "Orlan (Sea Eagle)-E" spacesuits. There was a remote scanning session with the use of robotics and virtual images alongside simulated astrophysical observations. Alexander Smoleyevsky took part in three extravehicular walks out on the Martian surface; Diego Urbana accompanied him in the first and in the third walks, and Wang Yue, in the second.

So, all in all there were three extravehicular (EV) exits. They came off well, with all the assignments fulfilled. Using specially designed instruments, the cosmonauts scooped up samples of Martian ground, and worked with astrophysical instruments. Martian surface was also explored by the computerized robotics apparatus "Gulliver" at a distance, from the landing

module. The landing party took readings on environmental parameters and collected ground samples as their Mars rover moved along the assigned route. There were also experiments with the use of imitation facilities and computer simulation of driving control, as close to reality as possible. This training experience showed it was possible to simulate professional activities in a variety of fields, and make them a real thing. A good lesion in activity learning!

UNEXPECTED EMERGENCY SITUATIONS

One such emergency was simulated on the first and second December of 2010. Lasting 22 hours and 48 minutes, it imitated a short circuit in the central feeder switchboard and its subsequent ignition. This switchboard supplied electrical power to the medico-technical complex of the station. The actions of the crew on duty in fire control were watched by representatives of the

Federal Ministry in charge of civil defense and emergency situations. Although life support systems were out of commission for 19 hours and 8 minutes, the dwelling space parameters stayed within permissible limits and had no effect on the fitness of the testers. They were okay. The crew perceived this make-believe emergency as real. Its members acted according to instructions, showing self-control and presence of mind under stress. Only on the second of December of 2010, with the emergency situation called off, the men were informed it was a staged event.

Another staged emergency took place between the 18th and 25th April of 2011: an all-out communication blackout. No messages, no information exchange between the crew and the ground control center. No news about what was happening outside, in this country and abroad. The telemedicine system was also out. Only the computer server was on to enable the crew to send back data on daily medical control and results of scheduled experiments. For security the emergency communication link was not switched off either, and television observation was still on. All through this

emergency the crew was relieved of life support control, with duty officers of the ground services taking over. Still and all, the testers could adjust temperature and humidity at their discretion within prescribed limits.

As shown by the "flight testimony", the relatively short information blackout (seven days) had as good as no effect on the mission. More than that, the crewmen even improved their performance through greater initiative and self-reliance. But with the communication blackout over, the information exchange level dropped somewhat in intensity because of the adaptation of the sensory system of the organism to information deficiency.

EXPERIMENT COMPLETED

In keeping with the program, the hatch of the medico-biological complex was flung open on November 4, 2011, that is nearly eighteen months after the start of the megaproject.

Next came intensive medical examinations and data management, carried out between November 4 and November 25, 2011. Doctors of the RAS Institute of Medico-Biological Problems, of the RAS Central Clinical Hospital and Russian Cardiological Research Center pronounced their verdict: the men were in good health.

The simulated 520 day interplanetary flight was a success. Kept in total isolation, all members of the crew displayed a high level of efficiency and motivation. Their fitness was up to the mark. The tight program of research was fulfilled with much success. And so was the program of testing innovative means of prevention, diagnostics and medical assistance. An information system was developed making it possible to ensure the vital activity of the crew as well as transmission of scientific, medical and personal information. The crew members learned knew skills and knacks. The system of psychological support proved effective as well, with the testers taking an active part in its organization and upgrading. The experiment was a "first" in many ways. In modeling human activity on the surface of another planet, for one. In testing life support systems that showed good performance in a time span close to the time of a real interplanetary mission.

Preliminary analysis of the collected data shows: staying within an artificial dwelling medium causes changes in the phenotypical characteristics of congenital immunity receptors identifying foreign antigens.

Formed thereby are new functional interactions between microbial communities and the ambient medium that could trigger changes in the action of microorganisms on the human organism. The simulated mission was a test for the all-round system of medical control and assistance, including methods implicated in the monitoring of the functional abilities of the organism during work on the surface of other planets.

The results of this long-term experiment were discussed in detail by an international symposium held under the auspices of the Russian Federal Space Agency, the Russian Academy of Sciences and the RAS Institute of Medico-Biological Problems in April of 2012. The data of the "Mars-500" project will be a reference point in designing a system of medical-technical support of interplanetary missions and will contribute to new research tasking.