Total Ionising Dose (TID) exposure in LEO orbit comes from various sources (trapped protons, trapped electrons, solar protons, secondaries). The video below illustrates the TID levels received behind 5mm of Aluminium shielding as the orbital altitude rises (the mission duration and inclination have been fixed). Higher LEO missions become increasingly challenging, particularly if COTS parts are being used.
Radiation analysis and assurance should be started as early in a project as possible for feasibility assessments and to help inform part / equipment selection.
The Sun is becoming increasingly active, as expected as it heads towards a solar maximum. The Sunspot number is a good indicator of the level of activity, and currently it is tracking above predictions for cycle 25. Will it peak similar to cycle 24, or to the level of cycle 22/23? (plot from SWPC)