The production of materials with end-use properties, and high performance materials in low temperature environments, or where radiation is high, is difficult. Low earth orbit is one place where in addition to micro level space debris and extremes in temperatures, the requirement is for long-lasting materials with no degradation from these effects. On the nanolevel the challenges of developing new composites using nanotubes and exfoliated graphite scaffolds also need computational methods to be used in the design. The design of new materials using polymer blending methods speeds up and is enhanced by high performance computing simulations, that also predict the behavior of these materials. This paper covers current computational methods in designing polymer blends for extreme environments, and simulation strategies to predict the behavior in such environments.