The invention of freeze dried food for use in space flights solves many of the problems associated with bringing normal food on such a mission, including space constraints and the risk of food spoilage during protracted trips.

Origins

The lack of gravity in space makes normal eating and drinking impossible; to prevent foods and liquids from floating around freely within the spacecraft, causing potential technical problems, freeze-drying is utilized.

Evolution

In the early days of space exploration, powders, cubed foods and squeezable tubes were the norm. As the years passed, these offerings gave way to improved food quality and menu diversity, and freeze-dried foods became easier to reconstitute and reheat, while such items as tubed meals disappeared altogether.

Types

Thanks to the freeze-drying process, astronauts today enjoy a wide variety of food options including shrimp cocktail, butterscotch pudding and ice cream. Meals are designed to meet the Recommended Dietary Allowances for calories, vitamins and nutrients, and astronauts select their meals several months before their trip.

How It Works

Freeze-drying, also known as Lyophilization, involves first freezing the food, then reducing the surrounding pressure to allow for sublimation (transformation directly from a solid to a gas form) of water in the frozen substance.

Use in Space

Freeze-dried foods are packaged in uniformly shaped, single-use containers of several different sizes for easy storage and disposal. Packets are cut open with scissors, water may be added for reconstitution, and food may be reheated in an onboard oven/microwave.

Source:

Nasa: Food for Space Flight

Freeze Drying Info: Process-Freeze Drying

Amazing Kids: The Universe Explorer: Inventions from Space