All earth-orbiting spacecrafts are susceptible to impacts by meteoroids and pieces of orbital debris. These impacts occur at extremely high speeds and can damage flight-critical systems, which can in turn lead to catastrophic spacecraft failure. With the advent of many new high-strength composite materials and their proliferation in aircraft applications, it is necessary to evaluate their potential for use in long-duration space and aerospace structural systems. This paper presents the results of several experimental investigations in which several different composite materials were tested for their ability to prevent the perforation of the inner walls in multi-wall systems subjected to hypervelocity projectile impact. Damage to multi-wall systems that employ composite materials is compared to damage in traditional all-aluminum multi-wall structures of similar geometry and weight under similar impact conditions. The advantages and disadvantages of using composite materials in perforation-resistant multi-wall structures are presented and discussed. The analyses performed show that the effectiveness of multi-wall systems with composite materials varies significantly depending upon the location within the multi-wall system of the composite materials. Based on the results obtained, it appears that composite materials are most effective when used as the middle wall of a triple-wall system.