Space Station: a unique international resource for research
by European Space AgencyMore articles in ISS
The United States and its partner nations began building the International Space Station four years ago. The orbiting outpost has been in space longer than all 110 Space Shuttle flights to date combined. But many people still ask what NASA and its international partners are accomplishing with it. In a personal column, former astronaut Dr. Jan Davis, now director of Flight Projects at the Marshall Center, discusses the types of experiments being conducted onboard the orbiting research outpost.
The United States and other nations began building the International Space Station four years ago, and this orbiting outpost has been in space longer than all 110 Space Shuttle flights to date combined.
However, people still ask me, “What are we doing up there?”
What we’re doing up there — besides learning how to live in a harsh environment, working peacefully with former adversaries, and laying the groundwork for the future exploration of the solar system and beyond — is scientific and commercial research.
With scientists monitoring and controlling their experiments from the ground, Space Station crews are growing animal and human tissues, key components of human metabolism, as well as plants and antibiotics in order to gain insights that will improve the health of humans, animals and plants on Earth. Furthermore, they are making or testing materials with obscure names like colloids and zeolites, which have technological and economic importance to our modern society in fields ranging from computers to food to petroleum processing.
This research is similar in many ways to research we do on Earth that is so important to our high-tech society. Yet some would question why this country should spend the time and resources to build a laboratory in space when we have thousands of labs on Earth.
The answer: weightlessness, or what scientists call microgravity.
For the record, the Space Shuttle and the Space Station aren't really weightless and gravity really isn’t absent. The influence of Earth's gravity extends 17 times the distance from Earth to the Moon! In fact, gravity is almost as strong on the Space Station as it is on Earth. But, as the Space Station orbits Earth, it is free falling.
If you parachuted out of an airplane on a set of scales, you and the scales would be falling at the same rate, so your weight would register as zero. Spacecraft and the astronauts and experiments inside are, in fact, falling back to Earth at the same very, very slow rate. So they behave like there is no gravity, and they appear to be weightless.
In the microgravity of an orbiting spacecraft, physical and chemical reactions aren’t pushed, prodded and hurried along by Earth’s gravity. Microscopic structures aren’t deformed by gravity. The human body behaves differently. Things that look and work a certain way on Earth don’t act the same way in space.
When you eliminate processes caused by gravity — such as sedimentation that makes heavy materials sink or convection that makes hot air rise — it is easier to grow crystals, study the way metals form, and even to pinpoint how fires burn.
We have conducted much useful science aboard the Space Shuttle, but those missions were limited to about two weeks. Some chemical reactions or plant growth experiments need more time to develop. The Shuttle is a good place to do science, but it’s like doing science on a camping trip. A permanent laboratory like the International Space Station offers scientists a work environment more like the ones they have on Earth.
From November 2000 to July 2002, five crews of astronauts and cosmonauts have lived and worked on the Station. They have conducted more than 50 different experiments, operating for more than 75,000 hours. NASA flight controllers and science teams at NASA centers, universities and companies around the world have supported these experiments. Today, the fifth crew is continuing that research and will bring the total crew time devoted to research to more than 1,000 hours.
One of the experiments that is just winding up on the Station grew soybeans, the largest single source of protein and oil in the American diet, representing a multi-billion-dollar market share in the food and animal feed industries. A seed company is funding this research because it may result in soybeans with improved oil, protein, or carbohydrate content, as well as other benefits of commercial value.
Another experiment taking advantage of the Station’s unique low-gravity lab is producing drug capsules no bigger than a human blood cell. In the future, these “microcapsules” could be manufactured on Earth and then, placed and activated directly at the site of a cancer tumor, reducing the unwanted side effects experienced by chemotherapy patients.
Both the soybean and drug capsule experiment and about one-third of all the investigations on the Station are so promising that they are commercial experiments being sponsored by industry.
Many experiments are studying how space flight changes the human body. Astronauts lose bone mass, but then regain it when they return to Earth. By studying that process, we may learn how bone loss differs by gender, age and race and develop exercises or drugs to prevent bone loss during long space missions. But the results may also have applications to bone disease such as osteoporosis on Earth.
An experiment that just came back from the Station studied materials called colloids for more than a year. A colloid is a system of fine particles often suspended in a fluid. Some common examples are paint, milk and ink. They’re also found in copy machine toner, computer screens, anti-slip floor coatings, and a variety of manufacturing processes such as polishing silicon for computer chips and removing the bitter tastes from many wines and fruit juices. Since fluids behave differently in low gravity, we can learn more about colloids and refine them for use in new products or improve existing ones.
In addition to serving this generation of scientists, the International Space Station is inspiring a next generation of scientists who will make the next generation of discoveries that will improve our lives. Astronauts using some simple toys have used the low-gravity environment to demonstrate basic principles of physics to students in a way no teacher could do on Earth. Students themselves are able to use the Internet to command a camera onboard the Station to photograph geographical and man-made features on Earth and receive their pictures in the classroom.
These are just a few examples of the research aboard the International Space Station. For more information about science aboard the Station and photos that take you inside the world’s only space laboratory, visit our Space Station science operations Web site at: http://www.scipoc.msfc.nasa.gov/
Note: Dr. Jan Davis, a Huntsville, Ala., native and former astronaut, is director of the Flight Projects Directorate at the Marshall Center. She began her career at NASA’s Marshall Space Flight Center in 1979 as an aerospace engineer. She joined NASA’s astronaut corps in 1987 and spent more than 670 hours in space over the course of three Space Shuttle flights. In 1999, she returned to the Marshall Center, where she is director of the Flight Projects Directorate, responsible for developing Space Station components and building and testing special carriers that fit in the Shuttle and make delivery of Space Station parts easier. Flight Projects also staffs and controls the Station’s Payload Operations Center.