What do you think astronauts aboard the International Space Station (ISS) ate for Thanksgiving? Roasted turkey? Wrong answer. In "Orbital Thanksgiving," NASA tells us they had stuffed tortillas. The news release also gives details about food in space.
First, let's look at the Thanksgiving dinner.
On the Station, the holiday table is set with bungee cords and Velcro. There's no heirloom china or tablecloth. Astronauts eat from disposable plastic containers and aluminum pouches. Instead of a carving knife, scissors are more important for meal preparation.
But the dining room view is unmatched, more than 200 miles above the Earth, and the spirit of peace and good will is as warm as at any gravity-bound table. The diners on the Station hold a record among holiday travelers, during the course of a meal, they circle the Earth.
If the view is great, preparing the meals is quite difficult.
Here is a picture of a Russian cosmonaut preparing food in the ISS galley (Credit: NASA).
Space and zero gravity offer challenges for food preparation. There is no refrigerator or freezer aboard the Station, so food must remain good for long periods at room temperature. Many offerings are freeze-dried. Others are thermostabilized, just like some foods found in grocery stores that do not require refrigeration. Some items are canned, others, like candy, nuts and cookies, are fine just the way they are on Earth.
Now, let's return to tortillas.
Crumbly or loose foods can float out and contaminate the Station atmosphere, becoming an annoyance or even a hazard to crews and equipment. Many entrees and vegetables are packaged in a thick sauce that helps hold them in a bowl while they are eaten. Tortillas are favored over sandwich bread, because they create fewer crumbs and are easier to handle in microgravity. They also stay fresh longer than sliced bread.
You can find more explanations and images on this NASA's Space Food page.
NASA also provides another paper on space food (PDF format, 315 KB, 4 pages) if you really want more information.
Source: NASA/Johnson Space Center, via Science Daily, November 26, 2003