Because if you were to magically turn off the sun and were placed somewhere in the solar system wearing a space suit you'd still be in a dangerous radiation env

Because if you were to magically turn off the sun and were placed somewhere in the solar system wearing a space suit you'd still be in a dangerous radiation environment from interstellar radiation. The Sun is not the only source of dangerous radiation when making interplanetary trips. This NASA page has more info on that subject: https://www.nasa.gov/feature/goddard/real-martians-how-to-protect-astronauts-from-space-radiation-on-mars https://www.nasa.gov/feature/goddard/real-martians-how-to-pr...