MARS-500

MARS-500 was intended to study the psychological, physiological and technological challenges inherent to long-duration space flight. Among other hurdles to overcome, the experiment examined the physiological effects of long-term weightlessness, the effectiveness of resource management, and the effects of isolation in a hermetically-sealed environment. MARS-500's communication systems were designed with a 13-minute delay, to simulate the actual transmission time to and from a Mars-bound spacecraft.

The scientific goals of MARS-500 included the study of potential habitat designs, with a particular focus on medical and psychological support for the crew (who would necessarily be confined in a relatively small spacecraft, with relatively limited medical facilities, for the seven- to nine-month journey to Mars).[2]

A total of 640 experiment days were scheduled between 2007 and 2011, divided into three stages of differing length. During each stage, the crew of volunteers lived and worked in a mockup spacecraft. Communication with the outside world was limited, and was conducted with a realistic time delay of up to 25 minutes, to simulate the real-life communications lag between Mars and Earth. Similarly, a realistically limited supply of on-board consumables was provided for the volunteers.[3] Some conditions, such as weightlessness and cosmic radiation, could not be simulated.

The first fifteen-day stage of the MARS-500 experiment took place from 15 November 2007 to 27 November 2007.[4] The purpose of this stage was to test the technical equipment, facilities, and operating procedures for the voyage.[5]

The second, 105-day stage of the MARS-500 experiment began on 31 March 2009 when six volunteers started living in the experiment's isolated living complex.[6] On 14 July 2009, this stage of the experiment was completed.

The 520-day final stage of the experiment, which was intended to simulate a full-length manned mission, began on 3 June 2010 and ended on 4 November 2011.[7][8][9] This stage was conducted by a six-man international crew, consisting of three Russians, a Frenchman, an Italian/ Colombian and a Chinese citizen.[9] The stage included a simulation of a crewed Mars landing, with three simulated Mars-walks carried out on 14, 18 and 22 February 2011.[10][11] The experiment ended on 4 November 2011, with all the participants reportedly in optimal physical and psychological condition.[9]

In February 2013, the Proceedings of the National Academy of Sciences reported that four of the six crew members had considerable problems sleeping, and increased sleep and rest times, in behaviour compared to animal hibernation.[12] Participants also experienced a disruption to their circadian rhythm during confinement.[13]

The habitable module was the main living quarters for the crew. The cylindrical 3.6 m × 20 m (12 ft × 66 ft) module consisted of six individual crew compartments, a kitchen/dining room, a living room, the main control room, and a toilet. The individual bedroom compartments, which had an area of approximately 3 m² (32 sq ft) each, contained a bed, a desk, a chair and shelves for personal belongings.[15]

Overhead plan of the experimental complex.

The cylindrical medical module measured 3.2 m × 11.9 m (10 ft × 39 ft) and housed two medical berths, a toilet, and equipment for routine medical examinations. It also contained equipment for telemedical, laboratory, and diagnostic investigations. If a crew-member had become ill, they would have been isolated and treated in the module.[14]

The Mars landing module simulator was only used during the 30-day "Mars-orbiting" phase of the experiment. The 6.3 m × 6.17 m (20.7 ft × 20.2 ft) cylindrical module accommodated up to three crew members, and had three bunk beds, two workstations and a toilet. Its ancillary systems included a control and data collection system, a video control and communications system, a gas analysis system, an air-conditioning and ventilation system, a sewage system and water supply, and a fire-suppression system.[14]

The cylindrical 3.9 m × 24 m (13 ft × 79 ft) storage module was divided into four compartments:[14]

1. A refrigerated compartment for food storage
2. A compartment for storage of non-perishable food
3. An experimental greenhouse
4. A compartment containing a bathroom, sauna, and gym

The MARS-500 project posted a number of basic requirements for any potential candidates. These were:

1. Age: 25–50 years old
2. Higher education
3. Professional requirements:
   • general practitioner having skills of first medical aid
   • physician-investigator having skills of clinical laboratory diagnostics
   • biologist
   • engineer – specialist in life support systems
   • engineer – specialist in computer science
   • engineer – specialist in electronics
   • engineer – mechanic
4. Language skills: knowledge of the Russian and English languages at a professional level

The crew of the first 15-day stage of the isolation experiment was composed of six Russians: five men and a woman.[16] This stage of the experiment was conducted in November 2007.

• Anton Artamonov (born 1982), engineer, physicist and programmer
• Oleg Artemyev (born 1970), engineer and cosmonaut
• Alexander Kovalev (born 1982), engineer employed by IBMP's telemedicine laboratory
• Dmitry Perfilov (born 1975), anesthesiologist employed by IBMP's telemedicine laboratory
• Sergey Ryazansky (born 1974), crew commander, physiologist and cosmonaut
• Marina Tugusheva (born 1983), biologist, IBMP researcher

Marina Tugusheva, the only woman of the crew, was excluded from the longer missions.

The 105-day second stage involved a crew of six members, and ended on 14 July 2009.[17]

• Oleg Artemyev, Russian cosmonaut
• Alexei Baranov, Russian medical doctor
• Cyrille Fournier, French airline pilot
• Oliver Knickel, mechanical engineer in the German Army
• Sergey Ryazansky (commander), Russian cosmonaut
• Alexei Shpakov, Russian sports physiologist

More than 6,000 people from 40 countries applied for the 520-day third stage of the experiment.[18] The selected volunteers were three Russians, two Europeans and one Chinese.[19] They had a varying command of English, but not all spoke Russian.[20]

• Romain Charles, 31-year-old French engineer[21][22]
• Sukhrob Rustamovich Kamolov (Сухроб Рустамович Камолов), Russian surgeon[18][23]
• Alexey Sergeyevich Sitev (Алексей Сергеевич Ситёв), Russian engineer[18] and commander of the mission[24]
• Alexandr Egorovich Smoleevskiy (Александр Егорович Смолеевский), Russian physiologist[18][24]
• Diego Urbina, 27-year-old Italian-Colombian engineer[19]
• Wang Yue (王跃), 27-year-old Chinese instructor at the China Astronaut Research and Training Center[23][25]

The other member of the crew, a replacement, was Mikhail Sinelnikov (Михаил Олегович Синельников), a 37-year-old Russian engineer.[18] The mission started on 3 June 2010[26] and concluded on 4 November 2011, whereupon the participants entered a four-day quarantine before leaving the facility.[9][27]

Crew experiments included monthly operational research, consisting of recording electrocardiogram, respiratory samples and blood pressure, and a questionnaire about lifestyle, stress and possible complaints over the past month.

Quarterly dynamic complex studies included measurement and recording of blood pressure and complex cardiorespiratory parameters during the performance of functional tests with physical, mental and orthostatic load. Detailed questionnaires conducting psychological testing and standard outpatient dispensary studies were conducted before and after the series of studies.

Because of the long stay in weightlessness, a person gets hypokinetic disorders. To study this phenomenon IBMP has been conducting research in this area for many years, which has allowed construction of a detailed picture of the cause of hypokinetic disorders. Experimental results show the main cause of violations to be a change in the gravity-dependent mechanisms that are responsible for motoric activity under the influence of gravity on the body. The changes begin to occur because of the disruption of coordinated work by sensory systems, in particular skeletal support and proprioceptive ones. Data obtained during the experiments suggest that the support afferentation in humans acts as a mechanism of activation and regulation of activity of the postural-tonic system, and that the lack of skeletal support is the reason for discharge of the physiological and morphological changes that are common in conditions of weightlessness and microgravity.[28]

The main purpose of immersion experiments was to study potential effects of the flight (including unloading) on the support mechanisms of the body (spinal, supraspinal), on the state of the central nervous systems, and on motor function and hand-eye co-ordination.[29]

During the flight, there is a risk of fire in the spacecraft, and argon is planned as an inhibitor in the ship's atmosphere to reduce this risk. The use of argon can significantly reduce the concentration of oxygen in the atmosphere of a spacecraft without any harm to the crew and to create a so-called hypoxic environment. Hyperbaric experiments will complement the knowledge on the effect of fire-resistant oxygen-nitrogen-argon mixture on the human body with the help of an integrated assessment of the subject's body during a long stay in fire-resistant mixture. The tests will determine the level of mental and physical performance, assess the state of the cardiorespiratory system, hematological, metabolic and immunological parameters in blood, and conduct microbiological research and research that will improve existing support systems.[30]

To avoid health problems caused by irradiation during the flight to Mars, it is necessary to create a prediction model of radiation risk. The model should describe the risk of radiation sickness depending on the total dose received, decreased performance which causes an acute reaction, and the possible reduction of the overall immune system resistance to the other health risks of interplanetary flight.

The prediction model is created by exposing a group of monkeys to a radiation source (caesium-137). Radiological experiments are then conducted to study the radiobiological reactions of the main regulatory body systems (nervous, endocrine, immune, cardiovascular, hematopoietic), and spermatozoa and cytogenetic response to irradiation and analysis of long-term effects of exposure (life expectancy and carcinogenesis). The experiment uses male rhesus macaque aged 3–5 years. They are divided into groups of 10–15 monkeys in each group. The experiments were designed so that they mimic the real exposure of crew during the flight to Mars, including acute and chronic phases of disease.[31]

Among the biological and medical studies of MARS-500, the crew underwent a twenty-four-hour electrogastroenterography, using on-board medical equipment, to study the electrical activity in the human gastrointestinal tract.[32][33][34]