Space food

Space food is one of the most demanding applications of food processing engineering: every item has to be safe, stable and palatable inside the closed environment of a space capsule or space station. Space foods are processed to ensure quality and safety, and NASA scientists use specific processing techniques to make foods shelf stable at room temperature.

Fresh fruits and vegetables are minimally processed. They are sanitized with a 200 (ppm) chlorine rinse, air-dried, and then placed on a food tray ready to be stored in the fresh food locker. Some vegetables, like carrots and celery, are packaged in sealable bags. Because they spoil quickly, all fresh foods need to be eaten within the first few days of a mission.

For everything that has to last, four preservation routes are used. Thermostabilization, or heat processing, can extend shelf life to three years. Irradiated foods are shelf stable because they are sterilized by a dose of ionizing radiation. Lowering the pH and water activity can also stabilize foods. Freeze-drying removes water from foods, which inhibits microbial growth, and mold growth can be prevented by removing oxygen from packaging.

The food safety framework the whole industry now runs on came out of the same programme. HACCP (Hazard Analysis and Critical Control Point) is a food safety protocol developed as part of humans' outer space exploration program, and it came out of the Apollo Program for Human Spaceflight. Food for astronauts needed to be safe, so NASA, working together with a food manufacturer, developed the protocol in 1971.