%0 Journal Article %T The Self-Healing Capability of Carbon Fibre Composite Structures Subjected to Hypervelocity Impacts Simulating Orbital Space Debris %A B. A£¿ssa %A K. Tagziria %A E. Haddad %A W. Jamroz %A J. Loiseau %A A. Higgins %A M. Asgar-Khan %A S. V. Hoa %A P. G. Merle %A D. Therriault %A F. Rosei %J ISRN Nanomaterials %D 2012 %R 10.5402/2012/351205 %X The presence in the space of micrometeoroids and orbital debris, particularly in the lower earth orbit, presents a continuous hazard to orbiting satellites, spacecrafts, and the international space station. Space debris includes all nonfunctional, man-made objects and fragments. As the population of debris continues to grow, the probability of collisions that could lead to potential damage will consequently increase. This work addresses a short review of the space debris ¡°challenge¡± and reports on our recent results obtained on the application of self-healing composite materials on impacted composite structures used in space. Self healing materials were blends of microcapsules containing mainly various combinations of a 5-ethylidene-2-norbornene (5E2N) and dicyclopentadiene (DCPD) monomers, reacted with ruthenium Grubbs' catalyst. The self healing materials were then mixed with a resin epoxy and single-walled carbon nanotubes (SWNTs) using vacuum centrifuging technique. The obtained nanocomposites were infused into the layers of woven carbon fibers reinforced polymer (CFRP). The CFRP specimens were then subjected to hypervelocity impact conditions¡ªprevailing in the space environment¡ªusing a home-made implosion-driven hypervelocity launcher. The different self-healing capabilities were determined and the SWNT contribution was discussed with respect to the experimental parameters. 1. Introduction A major challenge for space missions is that all materials degrade over time and are subject to wear, especially under extreme environments and external solicitations. Impact events are inevitable during the lifetime of a space composite structure, and once they are damaged they are hardly repairable. More specifically, polymeric composites are susceptible to cracks that may either form on the surface or deep within the material where inspection/detection is often impossible. Materials failure normally starts at the nanoscale level and is then amplified to the micro-up to the macroscale until catastrophic failure occurs. The ideal solution would be to block and eliminate damage as it occurs at the nano/microscale and restore the original material properties. Self-healing materials are conceived as having the potential to heal and restore their mechanical properties when damaged, thus enhancing the lifetime of materials and structures. Typical examples of self-healing materials can be found in polymers, metals, ceramics, and their composites which are subjected to a wide variety of healing principles. Healing can be initiated by means of an external source of %U http://www.hindawi.com/journals/isrn.nanomaterials/2012/351205/