Experiment

Background

Spending long periods of time in space and carrying out activities there have become ordinary and no longer just special missions for astronauts. In space, astronauts are exposed to many kinds of radiation and are under the influence of microgravity. In addition, high-energy radiation such as ultrahigh-energy galactic cosmic rays, solar energetic particles mainly consisting of protons from the Sun, and particles trapped by Earth’s magnetic field are present (Figure 1).

Of these types of cosmic radiation, heavy-particle beams in particular have a strong effect on cells. How does such radiation influence the human body? How can we protect our bodies from the radiation? Can human beings reproduce in space? Finding the answers to these questions is extremely important for human beings to perform a wider variety of activities in space in the future.