How to eat freeze-dried food in space?

December 21, 2025 •

3 min read

In the 1960s, NASA began using freeze-dried food, improving on earlier, less palatable options. This guide explains how to eat freeze-dried food in space and the science behind preparing meals in microgravity, which is crucial for astronaut health and a diverse menu.

Quick Summary

Astronauts eat freeze-dried food by rehydrating it with water. Meals are in foil pouches and eaten with utensils, with Velcro and trays preventing spills in microgravity.

Key Points

Rehydration: Astronauts restore freeze-dried meals' texture and flavor by adding water.
Special Packaging: Flexible, laminated pouches prevent crumbs and have a water valve.
Galley Preparation: Meals are prepared in a galley area, using trays with Velcro.
Taste: Astronauts' taste is often dulled, leading them to prefer more seasoned foods.
Utensils: Standard spoons and forks are used, with surface tension helping the food stick.
Food Variety: The space diet includes a variety of food types to ensure nutritional completeness and boost crew morale.

The Science Behind Space Food

Freeze-drying removes almost all moisture from food while keeping its nutrients, shape, and flavor. This makes the food lightweight and compact, which is essential for space travel. On the International Space Station (ISS), astronauts rehydrate the food by injecting water into the flexible package. This process is designed to be simple and mess-free in a microgravity environment where crumbs or loose liquids could damage equipment. A wide variety of meals are available because food is important for mission success and morale.

Why Freeze-Drying is Ideal for Space Travel

Lightweight and Compact: Weight and volume are minimized, so more food can be transported.
Long Shelf Life: Freeze-dried foods can last for years without refrigeration, which is essential for long missions.
High Nutrient Retention: Freeze-drying retains up to 98% of the food’s nutritional value.
Improved Flavor and Texture: When rehydrated correctly, the food's taste and texture are close to their original state.

Preparing Your Freeze-Dried Meal in Microgravity

Preparing a meal in space is a straightforward process thanks to specialized equipment. For freeze-dried items, astronauts follow these steps:

Select a Meal: Astronauts can choose from a menu of over 100 items.
Access the Galley: Food is prepared and heated in a galley area with a table that has straps or Velcro.
Inject Water: The meal pouch has a one-way valve. Astronauts use a water dispenser to inject the right amount of hot or cold water. The water often comes from the spacecraft’s fuel cells.
Wait and Agitate: The astronaut waits for the food to absorb the water, typically 5 to 15 minutes. Massaging the pouch helps distribute the water evenly.
Cut and Serve: The astronaut uses scissors to open the laminated pouch.
Eat with Utensils: The rehydrated food can be eaten with a fork or spoon from the pouch or a “spoon bowl”.

Packaging and Tools for Eating

To prevent contamination and ensure mess-free meals, space food relies on strong, flexible packaging. The multi-layered laminate material keeps out oxygen and moisture, and the one-way valve allows water injection without spilling. Eating tools in space are conventional, but with some changes. Food trays with hook-and-loop fasteners (Velcro) hold packages, and utensils are used to scoop food that sticks to the spoon via surface tension. Salt and pepper are added in liquid form to avoid floating particles.

Freeze-Dried vs. Other Space Food

Astronauts eat more than just freeze-dried items. The menu is varied to prevent palate fatigue and ensure proper nutrition. Here is a comparison of different types of space food:


Aspect	Freeze-Dried	Thermostabilized	Fresh Food (Limited)
Preparation	Requires rehydration.	Ready-to-eat or warmed.	Ready to eat.
Shelf Life	Very long (5-25 years).	Moderate (up to 5 years).	Very short (days to weeks).
Weight/Volume	Very low, compact.	Moderate.	High.
Nutrient Retention	Excellent (up to 98%).	Good, but heat can degrade nutrients.	Excellent.
Packaging	Flexible pouches with a water port.	Pouches and some cans.	Simple packaging.
Best For	Extended missions.	Variety, entrees.	Morale boost.

The Experience of Eating in Space

Microgravity can cause nasal congestion and dull an astronaut's sense of taste and smell. This is why astronauts often prefer spicier or more flavorful foods. Food connects astronauts to their home and provides comfort during long missions. Modern space food has evolved, offering a diverse culinary experience. Researchers at NASA's Space Food Systems Laboratory continue to develop new food technologies, including fresh food growth and advanced preservation methods for long missions. For further reading on the evolution of space cuisine, the Smithsonian's Air and Space Museum has a detailed overview.

Conclusion

Eating freeze-dried food in space involves rehydration and controlled consumption, all designed to overcome the challenges of microgravity. Each step, from the packaging to the act of adding water, ensures astronauts have safe, nutritious, and palatable meals. Freeze-dried technology has been instrumental in allowing humans to explore space for extended periods, providing a lightweight, long-lasting, and nourishing option. As we plan more ambitious missions, innovations in space food will continue to evolve and adapt to our needs.

Frequently Asked Questions

Freeze-drying, or lyophilization, is a process where frozen food is placed in a vacuum chamber and gently heated. The ice sublimates, turning directly into vapor and leaving behind lightweight, dry food that retains most of its original shape and nutrients.

It's ideal for space travel because it's lightweight, takes up minimal storage space, has a long shelf life, and is easy to prepare with the spacecraft's water supply. It also retains excellent nutritional value and flavor.

Astronauts use a water dispenser to inject water into a one-way valve on the food package. After a brief wait, the food is ready to eat.

Freeze-dried foods are stored in flexible, four-ply laminated pouches. These pouches are vacuum-sealed to maintain freshness and have a special port for water injection.

Yes, astronauts use regular spoons and forks. On the ISS, they often use a specialized 'spoon bowl' and a tray with straps or velcro to keep their food and utensils from floating away.

Microgravity causes a fluid shift in the body, leading to nasal congestion. This reduces the sense of smell, which impacts taste, making astronauts prefer spicier foods.

Besides freeze-dried meals, astronauts also eat thermostabilized foods, irradiated meats, fresh fruits and vegetables (early in a mission), and natural-form foods like nuts and granola bars.

No, while NASA has used freeze-drying, astronauts on the Apollo 11 mission ate freeze-dried bacon and peaches, but not ice cream.