a. Single event effects shall be analysed for spacecraft and planetary-mission systems to be operated within any of the following radiation environments:
1. trapped proton belts (terrestrial and other planetary belts, such as Jovian);
2. solar protons and heavier ions;
3. galactic cosmic-ray protons and heavier ions;
b. The mission environmental specifications shall define all the relevant environments to be analysed.
NOTE In some special circumstances, the following environments can also make an important contribution to SEE:
• secondary protons and neutrons, which are generated in atmospheric showers in the planetary environment or within massive spacecraft or planetary-lander structures.
• neutron environment in close proximity to radioactive or nuclear-energy sources, e.g. RTGs generating thermal or fission-spectrum neutrons.