What radiation hazards exist in space and how do they affect spacecraft?

Space radiation includes: Solar radiation - UV, visible, IR heating plus particle events during solar flares; Galactic cosmic rays (GCR) - high-energy particles from outside solar system; Van Allen belts - trapped charged particles around Earth (electrons and protons). Effects on spacecraft: Single Event Effects (SEE) - bit flips, latch-up in electronics; Total Ionizing Dose (TID) - cumulative damage to semiconductors; Displacement damage - crystal lattice damage in solar cells and sensors; Surface charging and deep dielectric charging. Mitigation: Radiation-hardened components, Shielding (aluminum, tantalum), Redundancy, and Error detection/correction. Orbit selection affects exposure (LEO below inner belt, GEO above outer belt, MEO in worst environment). Solar cycle affects particle flux. Mission design includes radiation analysis and testing.