At first, astronauts had only 10 kinds of food, but now it has increased to hundreds. Astronauts must eat four meals a day, and the recipe will not be repeated for a week. Some people think that astronauts' food is made into toothpaste, which must be boring. In fact, this is the case of early astronauts, and now it is not what it used to be. Astronauts can eat sausage pies, spicy grilled fish, roast beef with potatoes, buttered bread, lobster sauce, tuna salad, biscuits, chocolate, yogurt, preserved fruit, juice and other delicious dishes in space. American astronauts can even drink their favorite Coca-Cola. However, astronauts can't eat whatever they want. All diets must be strictly controlled by nutritionists on the ground. When the astronauts on the American space shuttle eat, they first take out the plastic bag marked "Which day and which meal" from the food cabinet. There are seven kinds of food in each plastic bag for astronauts to eat. Space food is dehydrated food. Before eating, you can put food into a bowl-shaped container, then inject a certain amount of water into the container with a syringe, and then heat it in the oven. It takes less than half an hour to cook a meal.