There are several classifications for food that is sent into space:
- Beverages (B) – Freeze dried drink mixes (coffee or tea) or flavored drinks (lemonade or orange drink) are provided in vacuum sealed beverage pouches. Coffee and tea may have powdered cream and/or sugar added depending on personal taste preferences. Empty beverage pouches are provided for drinking water.
- Fresh Foods (FF)– Fresh fruit, vegetables and tortillas delivered by resupply missions. These foods spoil quickly and need to be eaten within the first two days of flight to prevent spoilage. These foods are provided as psychological support.
- Irradiated (I) Meat – Beef steak that is sterilized with ionizing radiation to keep the food from spoiling. NASA has dispensation from the U.S. Food and Drug Administration (FDA) to use this type of food sterilization.
- Intermediate Moisture (IM) – Foods that have some moisture but not enough to cause immediate spoilage.
- Natural Form (NF) – Commercially available, shelf-stable foods such as nuts, cookies and granola bars that are ready to eat.
- Rehydratable (R) Foods – Foods that have been dehydrated by various technologies (such as drying with heat, osmotic drying and freeze drying) and allowed to rehydrate in hot water prior to consumption. Reducing the water content reduces the ability of microorganisms to thrive.
- Thermostabilized (T) – Also known as the retort process. This process heats foods to destroy pathogens, microorganisms and enzymes that may cause spoilage.
- Extended shelf-life bread products – Scones, waffles and rolls specially formulated to have a shelf life of up to 18 months.
More common staples and condiments do not have a classification and are known simply by the item name:
- Shelf Stable Tortillas – Tortillas that have been heat treated and specially packaged in an oxygen-free nitrogen atmosphere to prevent the growth of mold.
- Condiments – Liquid salt solution, oily pepper paste, mayonnaise, ketchup, and mustard.