“…From this perspective, the shielding effects of materials and structures already present in the spacecraft, but designed for other purposes, are important. In fact, the Micro-Debris Protection System (MDPS), the Multi-Layer Isolation (MLI) materials, and the primary aluminum shell, constituting the Habitat Protection System (HPS), designed to have good ballistic, thermal, and structural properties, respectively [4], can also offer good protection from direct radiation interaction [5]. However, the presence of extremely energetic heavy ions in the GCR spectrum, such as Fe, that can penetrate tens of centimeters of shielding materials, producing a secondary particle cascade, is a big concern for both the human crew [3] and the electronics inside the spacecraft [8].…”