Cosmic Rays
From librae wiki
Cosmic Rays are one of the biggest obstacles to interstellar travel. The strongest manifestation of hate the void has for humans, these particles originate from stars and destroy flesh and tech alike.
To protect from the rays, voidcraft or human habitats have to deploy magnetic fields, which consume a lot of energy, or some kind of physical protection.
Exposure to the cosmic rays will lead to irreparable damage to electronics or cancer in humans. Fortunately, current medical technology can heal cancer with minimal damage, but still this requires screening, expensive and excruciating care, thus exposure should be avoided.
