Solar wind — a stream of charged particles from the Sun — is normally deflected around Earth by the magnetosphere. During strong solar activity (CMEs, solar flares) the magnetosphere compresses and particles can reach satellite orbits, degrading electronics unless the spacecraft is shielded.
deflect if particle_r > R_shield · shieldStrength
hit_probability ∝ solarActivity / (shieldStrength · hardening)
health(t+dt) = health(t) − hits(t)·damage/hardening
- Solar activity — spawn rate and energy of incoming charged particles (0 = quiet Sun, 3 = severe storm).
- Magnetosphere strength — the effective radius of Earth's protective field; a bigger field deflects more particles before they reach orbit.
- Satellite altitude — moves the satellite's orbit closer to or farther from the compressed dayside magnetosphere.
- Satellite hardening — radiation-hardened electronics absorb hits with less damage to health.
- Trigger CME burst — simulates a sudden coronal mass ejection: a short spike in particle rate and energy.
Real-world application: space weather forecasters (NOAA SWPC, ESA) monitor exactly this solar-activity-vs-shielding balance to warn satellite operators when to switch electronics to safe mode during geomagnetic storms.