Items from the shuttle menu are available for sampling along with fresh food that must be consumed early in the mission since the shuttle carries no refrigerator or freezer to save weight and space. Dehydrated shrimp cocktail remains the astronauts consistent favorite. Former astronaut Story Musgrave always flew with it. He would eat it at least two times a day. Space agency dieticians use a lot of tricks to preserve the food, reduce weight and still make it appetizing.
Some food is dehydrated, while others are dried much like beef jerky.
Many of the meat products are treated with high heat to kill microorganisms. Currently the only item irradiated is beefsteak. Dieticians also try to accommodate different tastes and needs. Janice Voss, the payload commander for the upcoming Shuttle Radar Topography Mission, is a vegetarian and said there was no problem finding something to eat. We get to pick our own menus and there are quite a few vegetarian foods on the regular menus.