宇宙航空環境医学 Vol. 53, No. 4, 79, 2016

2.　Mars Analog Simulation at Mars Desert Research Station by Team Nippon

Hiroyuki Miyajima

International University of Health and Welfare, 4-3, Kozunomori, Narita, Chiba, 286-8686 Japan

The Mars Desert Research Station （MDRS） in Hanksville, Utah is designed for long term habitation experiments and simulations of Extra Vehicular Activities （EVA） on Mars’s surface.　Team Nippon （Crew 137）, organized by Mars Society Japan participated as one of the crews of the MDRS 2013-2014 crew rotations.　The crew, consisting of six members, conducted a two-week habitation experiment researching space food, hygiene control, logistics and life support, and EVA.　Team Nippon was the first team consisting of all Japanese crewmembers, which was led by its commander, Professor Hiroyuki Miyajima.　Experiments regarding space food and hygiene control were led by Professor Naomi Katayama, and experiments regarding logistics, life support, and EVA were led by Professor Miyajima.
　【Food and Logistics】　The food science and nutrition research group applied minimal water usage cooking and clean up methods developed for cooking and serving foods after a disaster, as the cooking method designed for a mission to Mars.　It included hygiene control, daily health monitoring, and minimizing waste.　Preserved rice and soup were prepared using minimal hot or cold water.　The preserved foods did not require water for cooking.　In addition, plates and bowls were wrapped with clear plastic wrap, thus avoiding the need to be washed with water.　Water used for cooking, drinking, and dishwashing was portioned at 2.5 liters/Crewmember （CM）-day, 1.9 liters/CM-day, and 0.4 liters/CM-day respectively.
　Over the experiment’s two week period, every member’s body weight was maintained due to the team nutritionist’s controlled diet.　At the start of the experiment, food corresponding to an 1,800 kcal/day diet was provided, but resulted in an increase of each member’s body weight on days they did not conduct EVA.　On such days, the members walked only 1,000 to 1,500 steps inside MDRS, which was considerably less than when conducting EVA.　Thus, their energy intake on non-EVA days was reduced to 1,600 kcal.
　In this mission, the food science and nutrition research group prepared 35 kg of Japanese food and 60 kg of American food taking up 180 cm³ and 272 cm³ of volume respectively.　The weight of garbage from food, toilet solid waste, and kitchen paper towels was 0.2 kg/CM-day.　As space was limited in the Mars habitation facility, the necessity to decrease weight and volume as much as possible was apparent.
　【EVA on Martian surface】　Crew 137 conducted seven sorties for conducting EVAs focusing on navigation for long range excursion.　Data was collected by a software program used to analyze routes by location, altitude and mobility speed.　The different destinations chosen on each trip provided a useful data set.　Although a contour map was used for deciding destinations for exploration, it was difficult to understand the real landscape of the desert surface.　The team experienced clamber or futility on forward movement several times, which proved that it was difficult to predict route settings without a knowledge-based map.　This experiment also provided great research on the real movement speed on unpredictable routes.
　The two mobility options of driving an All Terrain Vehicle （ATV） and walking were compared to determine optimal mobility approaches to destinations differing in terrain.　Although the mobility of an ATV provides a wider range of travel than walking, the stability of an ATV on a rough landscape was a significant issue to consider.　Since ATV travel was limited to routes past crews had created on their explorations, driving was trouble free.　However, off road driving was not only a challenge and dangerous, but impossible when encountering steep slopes in mountainous areas.　The data showed high mobility requires a detailed map of the landscape.　The parameters of mobility for early phase exploration should mainly be applicable to foot exploration rather than ATV exploration.