The so-called "bunkers" are actually special metal circles buried deep in the soil. When the instrument is officially operated driven by magnetic force, it will form a semisolid gas shield. Some surviving federal gathering places on the earth are all protected by such kind of bunkers. As for some places with chaotic atmosphere like the moonstar, they need more advanced bunkers.

Building these bunkers also needs energy. Many years ago, the Earth Federation was inspired by psionic ...