By the 1960s, NASA achieved an extraordinary technological feat by sending men into space but there was one more problem to solve - the food. Today most space food looks a lot like food here on the ground but a tasteless paste has come a long way from space exploration's early days. So how has space food transformed over the years? What are the challenges of transporting, cooking and disposing of food beyond the Earth's surface?

Because the first space flights lasted just a few minutes, there wasn't much need to carry food onboard. But by the early 1960s, John Glenn and the astronauts of Project Mercury were staying out for longer durations and had to eat. The first space foods were tasteless, to say the least. Most were semi-liquids that were squeezed from tubes and sucked up through straws. There were also bite-sized cubes of compressed and dehydrated foods.

By the time the Gemini mission launched in 1965, the food had gotten a bit more palatable. The astronauts were able to choose from a wider variety of foods, including shrimp cocktails, turkey bites, cream of chicken soup and pudding. The food was freeze-dried, meaning that it was cooked, quickly frozen and then put in a vacuum chamber to remove the water. Freeze-drying preserved the food for the flight without losing the flavor. To rehydrate the food, the astronauts simply injected water into the package with a water gun. For the Apollo program - the first to land men on the moon - NASA provided its astronauts with hot water, which made rehydrating foods easier. The mission introduced a spoon and a plastic container with food inside. After the astronauts injected water into the bowl to rehydrate the food, they opened a zipper and ate the food with a spoon.

The Skylab mission, launched in 1973, had even more of the comforts of home. The large dining room and table actually allowed astronauts sit down and eat. Skylab had refrigeration so it could carry a wider variety of foods different types of menu items in all. Food warmer trays allowed astronauts to heat their food in-flight. By the early 1980s and the launch of the first space shuttle, meals looked almost identical to what astronauts ate on Earth. Astronauts designed their own seven day menus selected from 74 different foods and 20 drinks. When the Space Shuttle Discovery launched in 2006, it was clear space food had entered a new realm. Restaurateur and celebrity chef, Emeril Lagasse, designed a menu that included selections like "kicked-up" mashed potatoes, jambalaya and bread pudding.

Today astronauts have dozens of different foods to choose from. A dietitian checks the menu to make sure that it contains enough nutrients. Astronauts need 100 percent of their daily requirements of vitamins and minerals. But because the environment in space is different than that of Earth, they need to adjust their intake of certain nutrients.Thus, astronauts need less iron than they do on Earth. Iron is mainly used to make new red blood cells but astronauts have fewer red blood cells in space. If they eat too much iron, it can cause health problems. Astronauts also need extra calcium and vitamin D, because bones don't get the exercise they need to stay strong in the weightless environment.

About a month before a mission launches, all food that will be taken aboard is packaged and stored in refrigerated lockers at the Space Center. It's loaded onboard the shuttle two to three days before launch. The space shuttle carries about 3.8 pounds of food, including 1 pound of packaging, per astronaut for each day of the mission. The astronauts get three meals a day, plus snacks.

Food packaging is designed to be easy to use, small enough and sturdy enough to keep food fresh for up to a year. Rehydratable foods are packaged in flexible bowls with lids. Foods can also be kept in cans with pull-off lids, plastic cups or flexible pouches.Condiments like ketchup, mustard and mayonnaise have their own packaging. Salt and pepper are stored in liquid form so that the crystals or granules don't float away. The space shuttle gets its water supply from fuel cells, which produce electricity by combining hydrogen and oxygen -- the main components of water.

Beverages (B) - Various rehydratable drinks. Fresh Foods (FF)- Foods that spoil quickly that needs to be eaten within the first two days of flight to prevent spoilage. Irradiated (I) Meat - Beef steak that is sterilized with ionizing radiation to keep the food from spoiling. Intermediate Moisture (IM) - Foods that have some moisture but not enough to cause immediate spoilage. Natural Form (NF) - Mostly unprocessed foods such as nuts, cookies and granola bars that are ready to eat. Rehydratable (R) Foods - Foods that have been dehydrated and allowed to rehydrate in hot water prior to consumption. Thermostabilized (T) - Foods that have been processed with heat to destroy microorganisms and enzymes that may cause spoilage. Shelf Stable Tortillas - Tortillas that have been heat treated and specially packaged in an oxygen-free nitrogen atmosphere to prevent the growth of mold. Condiments - Liquid salt solution, oily pepper paste, mayonnaise, ketchup, and mustard. There are several classifications for food that is sent into space

An average menu consists of 17% of protein, 32% of fat and of 51% carbohydrate Kilocalories is needed per person per day. Today astronauts have more than 300 different food to select from It is needed 1 pound of food, per astronaut for each day of the mission. In 1985 Coca-Cola created special recipe of the drink especially for spaceman. Eating also cause a problem of cleaning up; crews spent up to 90 minutes a day on housekeeping. It takes about 20 to 30 minutes to reconstitute and heat a meal.

Today's astronauts usually stay in space for several months, at most, they're able to carry all the food they'll need onboard. But in the future, space missions could be extended. To get to NASA's intended destination -- Mars -- and back again will take two years. Astronauts will need to carry foods that have to five year shelf life. They'll also need to start growing their own foods. NASA plans to grow fruits and vegetables on space farms -- greenhouses that are temperature-controlled, artificially lit and employ a hydroponic system, which uses nutrients instead of typical soil. Crops might include soybeans, peanuts, spinach, cabbage, lettuce and rice. Wheat berries and soybeans can be grown and processed into pasta or bread. The astronauts would then prepare these foods into home-cooked meals in a galley kitchen. According to NASA, a sample Martian dinner menu might include spinach and tomato crouton salad, wheat pasta with tomato sauce and a chocolate peanut butter soymilk shake.

Sources "Aromas and Odors in Space and their Effect on Appetite." Iowa State University. "Bone Loss in Space." Iowa State University. "Chinese Space Food to Hit Supermarket Shelves." Associated Press. "Food for Space Flight." NASA. "Fresh Fruits and Vegetables in Space." Iowa State University. "Fresh Nutrition Inside the Space Suit." Iowa State University. "Is that 'real' astronaut food?" Iowa State University. "Just How Nasty is Space Food?" Discover Magazine. "NASA and Food Irradiation." Iowa State University. "Space Food." NASA. "Space Food: From Squeeze Tubes to Celebrity Chefs." Space.com. "Space Food Packaging." Iowa State University. "Space Food That's Light Years Beyond Freeze-Dried." Christian Science Monitor, February 19, "Taking Humdrum Astronaut Food, and Kicking it up a Notch." The New York Times, August 29, 2006.