Exploring deep space presents several hazards, including the cosmic vacuum, radiation, weightlessness, and exposure to lunar dust during Moon missions.

Of all these risks, cosmic radiation stands out as the most dangerous. It encompasses electromagnetic radiation and high-energy charged particles, mainly protons, posing significant health risks to astronauts on extended missions.

The primary sources of cosmic radiation are solar activity, making it a critical factor to consider for the safety and well-being of space travelers.