Internal Charging Evaluation in Jupiter Exploration Mission

Jupiter has a similar radiation belt structure as Earth. The proton flux in Jupiter's magnetosphere is about 10 times of that in the Earth. The electron flux in Jupiter's magnetosphere is about 2～3 magnitude order higher than that of the Earth, and the maximum energy of electron is about 1 GeV. So, the anti-radiation design is one of the key technologies in Jupiter mission. Three elliptical orbits with different inclinations and two kinds of dielectric are selected, and the internal charging processes in time-varying electron environment are simulated. For Fr4 material, the conductivity is relatively small and the deposited charge will leak off when the spacecraft is far away from the center of radiation belt. The maximum charging field is determined by the maximum electron flux. For Kapton material, the conductivity is relatively large and the deposited charge will be accumulated between different orbits, so the charging field will grow gradually. Large inclinations of orbit will benefit in decreasing charging field. Comparing the internal charging behavior of Jupiter elliptical orbit with that of GEO orbit, it is found that the difference of charging field between Fr4 and Kapton in Jupiter orbits is smaller than that in GEO orbit.