In this period, the sun's radiation blows counter actively against the cosmic rays streaming in to our solar system, reducing an astronaut's exposure.
The astronauts, however, have to be saved against deadly solar flare during this time.
NASA is also planning a longer stay for astronauts on the ISS. Currently, astronauts take six-month shifts.
The space agency also plans to send humans to an asteroid or beyond to understand health hazards of long-term spaceflight, the report added.
