NASA/Spacelink File Name:6_9_7.TXT SPACE SCIENCE: OPENING NEW WORLDS OF KNOWLEDGE -------------------------------------------------------------------- - How big is the universe and how did it begin? - Why are the solar system's planets so different? - How does the sun create its energy? - How does weightlessness affect the human body? - How does Earth's environment work, and what are we doing to it? Questions. They are the fuel which fire our search for knowledge. And science is simply the means we use to find the answers. Even our word "science" comes from a Latin root meaning "to know." Space provides us with a unique vantage point and an unparalleled laboratory for science. From space, we can multiply -- and sometimes even revolutionize -- our knowledge of the laws which govern our universe. NASA's mandate from the very beginning has been to delve into the secrets of the cosmos, to expand our presence in the solar system, and to use those discoveries to gain a better understanding of the Earth. We have found many answers over the last three decades, but they in turn have raised new questions. To answer them, NASA is building on the legacy of the past with an ambitious space science program for the 1990s -- one which holds the promise for a decade of discovery that will eclipse all that has gone before. Fields of research range from Earth science, life science and microgravity science to space physics, solar system exploration and astrophysics. The questions we seek to answer affect not just America but the whole planet. Therefore, many space science programs are cooperatiave efforts with our intrnational space partners from around the world. Scientists will conduct experiments aboard full-scale research labs in space. Sophisticated orbiting telescopes will peer out to the edges of the universe. Unmanned probes will explore the mysteries of our solar system and the secrets of our sun. And Earth-observing satellites will help us begin to truly understand the fragile planet on which we live. In reality, the Space Shuttle, Spacelab, Space Station Freedom, and all our other space hardware are tools for science -- for answering both the questions we are asking now and the new questions those answers are sure to raise. USING SPACE AS A LABORATORY FOR SCIENCE Gravity dominates everything on Earth, from the way life has developed to the way materials interact. But in orbit around the Earth, the effects of gravity are barely felt. This microgravity environment is one of both challenge and opportunity. It presents the challenge of keeping space travelers healthy during extended periods of weightlessess. But it also gives us the opportunity to find new ways to combine and manipulate materials free from the constraints of gravity. By the end of the decade, research in both life and materials science will be in full swing aboard Space Station Freedom. In the meantime, Spacelab provides a short-term space station for manned science investigations. Microgravity experiments are also performed in the mid-deck of the Shuttle orbiter. LIFE SCIENCE Just three decades ago, no one was sure if a human could live in orbit. We have learned a lot about the effects of the space environment on life since then, but we must know much more before we send astronauts on extended space voyages or establish colonies on the moon or Mars. In space, blood and fluids accumulate in the upper body since gravity is no longer pulling them downward. Muscles do not have to strain to do work, and bones do not require as much strength to support a weightless body. What long-term effects do these and other microgravity influences have on astronauts' health and their ability to work in space? What would happen in the one-sixth gravity of the moon or the one-third gravity of Mars? How can remote medical care be provided for sick astronauts? A series of Spacelab Life Sciences missions in the early 1990s is designed to find some of those answers. Crews of expert biologists will be both the doctors and the patients in carefully planned medical experiments. The International Microgravity Laboratory missions, another Spacelab series, combine life science and materials experiments planned by scientists from 13 different countries. We will learn even more about how people, animals, and plants adapt to long-term weightlessness when Space Station Freedom is permanently manned. Eventually, astronaut stays aboard the Freedom Station will be extended to 180 days to approximate the physical effects of a year-long trip to Mars. "Closed loop" life support systems where food is grown in space and air and water are recycled will also be tested there. The advanced monitoring techniques developed for use in space and the increased understanding of fundamental biology are already being transferred to medical and scientific communities to improve the quality of life on Earth. MICROGRAVITY SCIENCE During the Shuttle era, we have begun to harness the potential of microgravity for materials science -- melting, molding, crystalizing, and combining or separating raw materials into useful products. It includes such varied processes as converting sand to silicon crystals for use in semi-conductors, producing extremely strong alloys and ceramics which can withstand high temperatures, separating biological materials into valuable drugs and chemicals, and studying the basic physical laws which influence these processes. Often, results can be achieved in space which would have been impossible on Earth. Metals of different weights can be combined to form alloys which would separate under gravity's pull. Near-perfect large crystals can be grown that would have collapsed on Earth under their own weight. Materials can be manufactured in suspension, without touching a container that might contaminate their purity. One microgravity experiment flown frequently on the Shuttle mid-deck is helping scientists determine the structure of certain proteins. Individual crystals of those proteins are grown during the Shuttle missions. Then the crystals -- much larger and more perfectly formed than any that could be grown on Earth -- are brought home for use as research tools in developing drugs to combat cancer, high blood pressure, organ transplant rejection, and many other disorders. Spacelab missions in the early 1990s, including the International Microgravity Laboratory flights and a United States lab series, will lay the groundwork for full-time materials research aboard Space Station Freedom. Experiments there should produce better materials to support future space explorations and for use here on Earth. ORBITING LABORATORIES SPACELAB Spacelab fits into the Space Shuttle cargo bay, transforming the orbiter into a full-scale research lab in space. It is a cooperative venture of the European Space Agency and NASA. Spacelab is a mix-and-match facility. Components include a large lab module which provides a shirtsleeve work environment for scientists, open pallets on which experiments may be mounted for direct exposure to space, and a pointing system for instruments requiring extra pointing accuracy and stability. Elements are chosen for each Spacelab mission according to the kind of science experiments to be conducted. SPACE STATION FREEDOM The manned portion of Space Station Freedom includes four modules. One provides living quarters for the international crew. The other three are laboratories, with one each being provided by the United States, Europe, and Japan. The labs are outfitted with experiment racks similar to those on Spacelab, while other experiments are mounted outside along a truss structure. Science will be conducted year-round aboard Freedom Station in fields as different as biology, materials science, astronomy and Earth observation. The first space station elements will be launched in 1995. Freedom will be manned for weeks at a time in 1996 and permanently occupied in 1999. "SEEING" THE UNIVERSE -- ASTROPHYSICS People have always looked at the stars and asked questions about what they saw. But until the space age, their view was limited by the hazy veil of Earth's atmosphere. The masses of colliding air above us distort light as it passes through them. That's why stars seem to twinkle. And other wavelengths of light, such as ultraviolet and X-rays from very hot stars or infrared rays from cooler objects, are mostly absorbed by the atmosphere and never reach the Earth. A large part of the story of stars and galaxies is told in this "invisible" light. By placing telescopes in space, above the obscuring atmosphere, we have begun to get a more complete picture of the universe. But the discoveries of the past are only the beginning. NASA and its international partners have embarked on an ambitious program for the 1990s that will usher in a whole new era in astronomy. Primary to that program is a series of four Great Observatories which will study the cosmos in all the hues of visible and invisible light. The first of those observatories is the Hubble Space Telescope. Launched in April 1990, this engineering marvel promises to revolutionize our understanding of the universe as much as Galileo's first telescope did almost 400 years ago. It will detect sources of visible and ultraviolet light 25 times fainter than is possible with any ground-based observatory. With it, we will see in 10 times finer detail than ever before. It will even allow us to "see back in time," as we view objects so far away that their light has travelled billionsn of years to reach us. The second in the series is the Gamma Ray Observatory, which will operate for four years beginning in 1991. It will examine stars and galaxies in the hottest, most energetic radiation wavelengths. The Advanced X-Ray Astrophysics Facility, which will go into service in 1997, will study X-ray emissions -- hotter than ultraviolet but cooler than gamma rays. The Space Infrared Telescope Facility, planned for late in the decade, will look for cool radiation such as could be emitted by distant planets. The Great Observatories are being aided in their search of the heavens by smaller satellites and by manned astrophysics missions. In December 1990, four astronomers spent more than a week aboard the Astro Spacelab mission. Telescopes mounted in the Shuttle cargo bay studied the universe in the ultraviolet and X-rays. By combining discoveries of these "eyes in the sky" in different forms of radiation, astronomers will know volumes more about the size and geometry of the universe and about how stars are born and die. In the process, they may determine how the universe began and even glimpse its ultimate fate. PROBING THE PLANETS -- SOLAR SYSTEM EXPLORATION When Galileo turned his first telescope upon the heavens, he was surprised to find moons orbiting Jupiter and what proved to be rings around Saturn. The planetary probes of the space age have furnished us with many more surprises -- surprises which have rewritten the science books of just 20 years ago. - Our "twin" planet Venus, though similar to Earth in size, density, and physical composition, is actually a raging inferno hot enough to melt lead, with a smothering carbon dioxide atmosphere and sulfuric acid rain. - There is a volcano on Mars as big as the state of Missouri, a canyon the length of the United States, and dry river beds that may once have carried liquid water. - More moons circle the four outer planets than even modern astronomers had guessed. They include barren chunks of rock, spheres of ice as smooth as a marble, and a volcanic pizza-colored moon which spews molten sulphur hundreds of miles into space. Now we are poised on the next step of planetary exploration. At the dawn of this decade, two new spacecraft -- Magellan and Galileo -- were speeding in opposite directions from the Earth to flesh out more detail in our knowledge of the planets. Magellan arrived at Venus in August 1990 to penetrate the cloud-covered surface with with radar and map its surface for a year. Galileo is on a six-year journey to Jupiter. Its route, designed to take advantage of the "slingshot effect" of other planets' gravities, allowed it to look for lightning on Venus and to study our moon's north pole as it passed Earth again. When it arrives at Jupiter in 1996, Galileo will drop a probe into the atmosphere to look for material left over from our solar system's creation, while the spacecraft orbits Jupiter to survey the planet and its moons. Mars Observer follows Viking's path to the red planet in 1992, taking the next step to prepare the way for human visitors. Later in the decade, Lunar Observer is planned to orbit the moon for a year, thoroughly mapping its surface and assessing its resources. By studying these diverse inhabitants of our solar system, and comparing the differences and similarities between them, we are learning more about the origin and history of these worlds and of the solar system as a whole. The more we know of our cosmic neighborhood, the greater our understanding will be of the scientific principles which govern our Earth. STUDYING OUR SUN AND ITS INFLUENCE -- SPACE PHYSICS "What is the sun?" someone asked in the last century. "If the science of astronomy could solve this great problem, it would be nearly capable of solving that of the entire universe." Sure enough, by 1900 an astronomer studying the sun discovered a "new" chemical element, helium, before it was known on Earth. Scientists analyze the sun as a star -- the star nearest to Earth and therefore the one that can be viewed in the greatest detail. Lessons learned from the sun can be applied to their understanding of all stars. But they are also interested in the effect the sun has on its family of planets -- especially Earth -- and the space between them. In addition to heat and light, the sun produces the solar wind, a hot electrified gas that travels through space at a million miles per hour, carrying particles and magnetism from the sun outward past the planets. Most of this potentially harmful speeding gas is deflected from the Earth by a magnetic field which surrounds it called the magnetosphere. However, changes in the sun like solar flares cause strong gusts in the solar wind, which in turn disturbs Earth's space environment. NASA has studied the sun and the solar-terrestrial (sun-Earth) environment with both telescopes and space probes over the years. But there are more questions to be answered in this field as well. In the mid-1990s, the solar probe Ulysses, a joint effort of the European Space Agency and NASA, will fly over the sun's poles to study the environment between our star and its planets. No spacecraft has ever ventured so far above or below the ecliptic plane in which the planets orbit the sun. Solar wind, radiation, dust and magnetic fields will be measured, as well as phenomena from the Milky Way and beyond. Several nations are also cooperating in the International Solar-Terrestrial Physics program. A series of spacecraft operating in different orbits will look for cause-and-effect relationships in the sun-Earth environment. They will study the magnetosphere and its long "tail" which trails behind Earth, the solar wind, the hot gas in interplanetary space, and the structure of the sun itself. GETTING THE "BIG PICTURE" OF EARTH -- EARTH SCIENCE AND APPLICATIONS The Apollo photos gave us a new vision of the Earth -- a fragile blue jewel suspended in the blackness of space. Today one of the greatest challenges facing the citizens of the world is preserving and protecting that fragile planet. But in order to preserve it, we must understand it. In the three decades of the space age, we have learned more about the Earth and its environment than in all prior years. Satellites survey land masses and monitor the weather on a continuous basis. But up to now, our knowledge of the environment has come from independent studies of different elements. Before the end of the 1990s, NASA and its international partners plan to launch a variety of spacecraft and sensors known collectively as the Earth Observing System. It will study the environment as a whole -- the planet's interior and crust, its vegetation and oceans, its atmosphere and winds, and their interaction with one another -- over an extended period of time. Equipped with specific knowledge of how the Earth system works, we can determine the wisest steps to preserve its beauty and life-sustaining capability for generations to come. The Earth Observing System will complement the observations of both manned and unmanned missions launched in the early years of the decade. The Upper Atmosphere Research Satellite will provide the first global measurements of the chemistry and dynamics of the upper layers of the atmosphere, while the Ocean Topography Experiment will make detailed measurements of entire ocean basins for several years. In addition, Atmospheric Laboratory for Applications and Science (ATLAS) Spacelab missions will study both the sun and the atmosphere. NASA's far-reaching space science program has many elements, but they all combine to increase our understanding of fundamental chemistry, biology and physics. It is from this body of knowledge that we can draw to make life better here on Earth. The great thinker Albert Einstein once wrote, "The important thing is to not stop questioning. Curiosity has its own reason for existing. One cannot help but be in awe when he contemplates the mysteries of eternity, of life, and of the marvelous structure of reality."