Wont claim following link addresses all aspects. Please have a look.
<a href="https://www.forbes.com/sites/jillianscudder/2017/06/16/astroquizzical-van-allen-belts-barrier-spaceflight/#25ef09076f8d" rel="nofollow">https://www.forbes.com/sites/jillianscudder/2017/06/16/astro...</a>