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Understanding Space Flight
Adapting to Space Might
When flying in space, the human body feels that it is in an environment very different from the ground. You spend your whole life on the ground with gravity—and in space, all of a sudden that changes. The body does a great job of quickly realizing this, and it starts to change to get used to this new world—a process we call adaptation. Adaptation to space flight affects almost every part of the body in one way or another: heart, muscles, bones, stomach, blood, even your inner ear (the part that helps you keep your balance). This can make the first few days of space flight very rough, sort of like living on a roller coaster!
Most of these changes don't have a negative effect while you are in space, but some can have large effects when you land on Earth again. For example, your body needs less blood while you are weightless, probably because it is easier to get blood (and oxygen) to all parts of the body without gravity. This adaptation takes a week or two. During that time your body lowers the number of blood cells and the amount of fluid circulating in your blood vessels. Some of the fluid (that is, water) is shifted out of the blood vessels and into other areas of the body (like into cells) or out of the body (in urine). This works fine in space, but when you come back to Earth, your body won't have enough blood, so we need to be careful that the astronauts don't faint on their return to Earth's gravity! To help prevent problems, about 45 minutes before returning to Earth, the astronauts drink a liter of salty solution to help them during and soon after landing.
The muscles also weaken during space flight. This is called "muscle atrophy." We're still working to understand the details of why this happens, but it seems that because the body doesn't use muscles the same way in weightlessness as on Earth, the unused muscles will weaken. Although this doesn't matter while an astronaut is orbiting the Earth, it is very important for walking around after landing. This is harder on crews on the International Space Station (ISS), who stay in space for months. The longer the flight, the weaker the muscles get. Astronauts exercise hard every day to try to avoid these changes.
Understanding and preventing the negative changes that occur during space flight is an important job. Researchers at the Nutritional Biochemistry Laboratory at NASA's Johnson Space Center in Houston spend a lot of time on this, because good nutrition may be one way to help keep astronauts healthy during space flight. In the next chapters, we will tell you all about the work going on in the Nutritional Biochemistry Laboratory, and also what good nutrition means to you!
Space History (and Present)
The Space Nutrition Team – Lin, Tim, Thea, and Diego – are here to guide us through the history of space flight, and through the many historical aspects of space nutrition. This team was created and developed with the help and love of our graphic artist.
Mercury was the United States' first space program that sent humans to space. Mercury astronauts were launched into space on either a Redstone or Atlas rocket, depending on how far they traveled.
Alan Shepard was the first American in space. He took his first trip to space less than 1 month after Yuri Gagarin's flight, and it lasted 15 minutes and 28 seconds. That first flight was a suborbital flight, meaning that it did not orbit the Earth.
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The Mercury program ended with Astronaut Gordon Cooper completing 22 orbits around the Earth and staying in space for a whole day (a little over 34 h).
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The Gemini program, Project Gemini, was created to bring NASA one step closer to going to the moon. It included the first 2-person missions, and the first space walk by an American!
Foods used in Project Gemini were a little better than the original items developed for Project Mercury. They included foods like shrimp cocktail, chicken and vegetables, pudding, and apple sauce.
In 1961, when the U.S. had had about 15 minutes of space flight experience, President Kennedy challenged us to get to the moon by the end of the decade. With tremendous teamwork and an outstanding effort, in 1969 the Apollo 11 crew landed on the moon. At 4:18 p.m. EDT on July 20, 1969, Neil Armstrong radioed the first words from the moon: "Houston, Tranquility Base here.
The Eagle has landed." Just under 7 hours later, he took the first steps out of the lunar module and proclaimed "That's one small step for man, one giant leap for mankind."
The Apollo astronauts were the first to have hot water in space, so the variety of space foods increased even more. On Christmas Day, 1968, the Apollo 8 crew ate a package of turkey and gravy and ate with spoons. The Apollo crews enjoyed bread slices with sandwich spreads and cheddar cheese spreads, and even frankfurters. Fruit juices were also added to the menu.
The first space station built by the U.S. was Skylab, depicted in the figure below. The goals of the Skylab program were to prove that humans could live in space for long periods of time, and to perform scientific experiments. Astronauts on Skylab used specially made equipment to keep an eye on, and better understand, what happens to the body when it is exposed to weightlessness for a long time. They also measured radiation from the sun and observed the Earth from space.
Skylab had one of the best space food systems. One area on the station had space for a dining room and table. A refrigerator and freezer were also available for storing food, and therefore the menu could be more extensive. The Skylab astronauts could choose from 72 different food items, including steak and vanilla ice cream.
Apollo-Soyuz Test Project
The Apollo-Soyuz program was the first joint space program of the U.S. and Russia, and resulted in one mission. The mission was 9 days (July 15-24, 1975), but a great deal of planning went into those 9 days.
During the Apollo-Soyuz mission, a U.S. Apollo spacecraft launched from the U.S. and docked (that is, connected) with a Russian Soyuz spacecraft that had launched from Russia. Engineers had to design a special docking module that would fit onto both spacecrafts. The figure above depicts this mission, with the Apollo capsule on the left and the Soyuz capsule on the right. Photos of this event are unavailable, as there was no third spaceship to take the picture from!
The Apollo-Soyuz docking module was basically a 3-meter-long (about 10 feet) tunnel, and it served as an airlock between the two vehicles. This was required because the interiors of the two vehicles had different atmospheres, with different pressures and different mixtures of gases, and the airlock allowed the 2 crews to meet in space without a sudden pressure change.
The Apollo and Soyuz crews shared meals and performed experiments together. This program was a big success overall, and paved the way for the future when these nations would work together again in space.
The Space Shuttle was the world's first reusable spacecraft. Shuttle missions were 5 to 16 days long, and had as many as 8 crew members. The part of the Space Shuttle that had wings was called the "orbiter." Inside the orbiter was the crew compartment (that is, the place where the crew members worked, ate, and slept). The crew compartment had 2 levels: the flight deck and the mid-deck (or middle deck). The flight deck was "upstairs," and was where the commander and pilot (and 2 other astronauts) sat and controlled the flight, and could see out the windows. The mid-deck was "downstairs," and was where most experiments were conducted, where the "kitchen" was, and where the bathroom was.
Shuttle astronauts prepared their food in the galley on the orbiter's mid-deck. The galley was a kitchen area, and had a water dispenser that could deliver warm or cool water. It also had a convection oven to warm foods. This oven was hot enough to warm foods, but it wouldn't be hot enough to bake foods like cookies!
The Shuttle-Mir Program was a series of space missions from 1994 to 1998. It consisted of 11 Space Shuttle flights to the Russian space station Mir. The goals of this program were to learn how to work with international partners, gain experience in successfully living in space for many months, and conduct scientific experiments related to biology, weightlessness (also called "microgravity"), and Earth's environment.
The crew members aboard Mir had their choice of American or Russian food. Astronaut Andy Thomas described the food this way: "The Russian foods were really good. The Russian soups were just outstanding." He went on to say "It was really a good selection of food, actually. The food is largely canned food and rehydratable foods, much like you might use on a camping trip or something like that, and I had more than enough to eat."
International Space Station
The International Space Station (ISS) is a giant environment for living and working that orbits the Earth once every 90 minutes. The ISS was built in sections called "modules" that were taken to space either in the Space Shuttles or on Russian launch vehicles. These huge modules, and other parts, were attached to the ISS by astronauts during space walks. The first module was launched in 1998, and construction of the ISS is nearly complete in 2011. Even though the ISS is traveling almost 200 miles above the Earth at 17,500 miles per hour, on a good night you can see it with just your eyes! Check out NASA's Web sites for when the ISS might pass over your head!
Exploring space is a huge challenge. It requires teamwork from countries around the world. Just as the United States has NASA, other countries have their own space organizations. The international space organizations represent 16 countries and are NASA's international partners (IPs). For the ISS, the IPs are the Canadian Space Agency, the European Space Agency, the Japanese Aerospace Exploration Agency, the Russian Federal Space Agency, and the United States' space agency—NASA. All of the partners work together to accomplish one task: learning more about space.
The ISS crews are international as well. Six crew members live on the ISS, and they come from the U.S., Russia, Canada, Japan, and Europe. The U.S. and its IPs make new foods to try to increase the variety of foods available to crew members.
All of the parts of the ISS were built on the ground by NASA and its international partners. For example, the Canadian Space Agency built a robotic arm; the European Space Agency built the Columbus Laboratory module; the Japanese Aerospace Exploration Agency built a Japanese Experiment Module that is composed of three segments and is known as Kibo, which means "hope" in Japanese. The Russian Federal Space Agency built the Functional Cargo Block, FGB for short, known as Zarya (the Russian word for sunrise), and NASA built the lab module called Destiny. These huge pieces were built in different places, at different times. They were never near each other until they were attached in orbit!
Nutrition – What is it, what does it have to do with astronauts, and what does it have to do with me?
In this Section, Lin, Tim, Thea, and Diego—the Space Nutrition Team—help us understand more about the world of nutrition research.
Biochemistry is a fancy word for studying how living organisms work—all the way down to the chemicals in the cells that make up the body. Nutritional biochemistry is the study of how nutrients in food affect how our bodies work. Every cell in your body requires many different vitamins and minerals as well as energy to keep you alive and healthy.
In one sentence, the job of the Nutritional Biochemistry Laboratory is to figure out how much of each nutrient (the calories, protein, vitamins, calcium, other minerals ... you name it) the body needs during space flight—in other words, the nutrient requirements for space flight. To figure out what the requirements are, the people in our laboratory do research. As we find out new information about these nutrient requirements by doing research, the information is handed over to specialists in NASA's Space Food Systems Laboratory. They have the tough job of developing foods and menus that will not only meet the nutrition requirements, but also obey the many other special rules that are made for space foods. These rules are discussed in more detail in the Space Food section ahead.
Research - Nutrition or Otherwise
So what is meant by the word "research"? To conduct research, scientists do experiments to learn about things in the world. Just as you do in your science fair experiments, researchers learn new things by asking questions, testing theories or hypotheses, observing how things happen, and making conclusions about things they learned. Once you know and understand how something works, you can predict how it will behave in the future. This process is called the scientific method. You use the scientific method if you've ever entered a science fair competition, and it is exactly what we at NASA use every time we do an experiment on the ground or in space. In the next few paragraphs, we'll walk you through the scientific method and we will also describe how we used this process for one of our experiments.
An experiment in born - Observation
Observation is the first step of the scientific method. We propose experiments when we want to answer questions about observations we have made. The answers that come from doing experiments are more reliable answers than answers that are only an estimate, or a guess. Science is based on answering questions with evidence or confirmed information. The more evidence you have, the better your conclusions will be.
What's a Hypothesis?
A hypothesis is an "educated" guess. It could be a guess based on a previous experience or a similar situation. It's more reliable than answering a question by saying "because I think so."
Let's say you had a lemonade stand and you noticed that you had a lot more sales one week than you did the next week. You would then try to think of differences between the weeks that could explain the rise in sales, and there would likely be many. Maybe you would decide that the outside temperature made a difference and people are more thirsty when it is warmer. The next step is to test your hypothesis that warmer temperatures influence lemonade sales at your stand.
The experiment is the next step of the scientific method. An experiment is the testing of your hypothesis in a controlled manner. This means that you have a well-defined process or procedure for each step of your experiment, so that someone else could repeat it. There are several ways to perform each experiment. When scientists propose to do an experiment, their proposal is reviewed by other scientists who are experts in that area. These reviewers can suggest ways for the scientists who proposed the experiment to make their experiment better. The best experiments are well planned and reviewed many times by many people and groups. This is just one step in the process of getting an experiment from an idea to space and back!
To test your hypothesis that temperature affects your sales, you could record (write down or enter into a computer) the outside temperature along with the number of sales each day. If you had an indoor lemonade stand, you could adjust the room temperature to be higher one week and lower the next week.
Data collection and Analysis of results
At the end of your experiment, you always want to have some sort of measurable outcome. Collecting good information from your experiment is important. Using tools that have been calibrated, or checked to make sure they are accurate, is important.
In the lemonade stand experiment, if you used a thermometer that was broken or didn't work properly, then your results and conclusions would not be accurate.
When you finish collecting information, or data, then you will want to determine what it all means. This process is called analysis. You could make a graph and plot daily temperature versus number of drinks sold, which would be an easy way for someone to quickly look at your data and interpret what, if anything, your experiment tells you—the conclusion of your experiment.
Excerpted from Space Nutrition by Scott M. Smith Janis Davis-Street Lisa Neasbitt Sara R. Zwart Copyright © 2012 by NASA. Excerpted by permission of Trafford Publishing. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
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