The Space Shuttle's food system consists of food products preserved by dehydration, thermostabilization, irradiation, and moisture control. A preassembled standard menu is provided for each crew member. This is supplemented with a pantry food supply. In case of emergency, the pantry is a contingency food source, but on a nominal mission it can be used to supplement meals, and pantry items can be exchanged with standard meal items to accommodate individual food preferences. Shelf life, storage temperature, volume, and weight have been the primary factors considered in the development of the Shuttle food system.