Humans fly to the moon again, and to the mars

―from a viewpoint of space medicine―

Abstract

　The Artemis Program, which is NASA's mission to return astronauts to the moon for the first time since Apollo 17 in 1972, is to establish a lunar base for preparing future manned missions to the mars. Manned space exploration started with rivalry between Soviet and USA during the decade of 1960s, and it ended by the lunar landing of the Apollo 11 in 1969. Thereafter, Soviet/Russia sought how to stay long in the closed narrow space station under a 0-G environment, while USA developed a reusable spaceship named space shuttle. And their common goal was the International Space Station (ISS) that had been built in 1998-2011. Since then, their attention expanded to space utilization including space resources such as the moon and asteroids. The Artemis Program is just one of them planned by USA involving several organizations including Japan, though vitalities of private sector and social economy have now become inevitable for the attainment. And besides, China has caught up the Program, Russia is looking for her own opportunity and India is saving the power.

　Advance in space medicine is indispensable for sustaining manned space activities. Fundamental issues for a long stay in the space station were itemized by using the Skylab stations flown the earth orbit for each 1, 2, and 3 months with 3 crews respectively, in 1972-74. Those issues uncovered by the Skylab mission were reflected and researched further in Space Shuttle and ISS. Main issues to be investigated at the lunar base, must be protection against radiation, group dynamics psychology in long-term space stay and highly advanced technology for circular agriculture. In order to keep physical adaptation of crews against changing G-level before and after a long-term travelling to the mars, such a spaceship as rotating about its axis to produce artificial gravity is required.