Two processes are of special importance in the preservation of rubber: oxidation, a chemical deterioration, and crystallization, a molecular restructuring that causes the material to loose its elasticity. Modern rubber, such as that found in NASM spacesuits, is highly susceptible to oxidation, and will slowly crystallize at room temperature.
Rubber can be preserved against oxidation by cold storage but only at the cost of consideraly accelerating crystallization. However, it was found that such low temperature crystallization is reversible through heating, and that crystallization occurring at sufficiently low temperatures will be completely reversed by returning the object to room temperature. This was found also to be valid for rubber that has already undergone appreciable chemical change through oxidation. Hence, cold storage provides an effective long-term preservation strategy for rubber.