SOLAR ASTRONOMY In 1965, the Space Science Board of the National Academy of Sciences stated: "There are three major reasons why (study of) the sun is important: first, because of its intrinsic interest as the only nearby star; second, because of its effect on the planets and, in particular, the earth and the human race; third, because it is a valuable astro-physical laboratory," ML 70-7497. The sun dominates the solar system and furthermore is the single most influential element that effects life on earth. Since Galileo's first telescope, man has been studying the sun, continually improving his instrumentation to better understand the earth's closest star. As observed from the ground, there is little indication of the complex phenomena that takes place on the sun or the effects they cause on the earth. The structure of the solar atmosphere is most complex. Superimposed on a seething layered structure with temperatures ranging from a "cool" 6,000 degrees centigrade to several million degrees as a wide variety of phenomena which contain or emit energetic particle radiation, are generally supported by magnetic fields, and which can erupt and within minutes dump the equivalent of millions of megatons of energy into interplanetary space in the form of damaging radiations of all kinds which are sufficient to change the environment of the earth in space, cause aurorae, magnetic storms, and radio communication blackouts, and present a radiation hazard to space travel. The magnetosphere in the earth's environment is generated by the interaction of the sun and the earth's magnetic field. Solar wind particles perturb the earth's field in many ways. Energetic particles from the sun cause the auroras and, with ionizing radiations, interfere with or completely disrupt communications. Highly energetic solar protons appear even as low as 80,000 feet following solar flares. Some U.S. and Russian meteorologists have conjectured that the formation of unusually large high and low pressure areas is triggered in an unknown way by solar protons striking the earth's upper atmosphere. The understanding of solar radiation effects is also important with regard to the detection of nuclear explosions. One method of detection involves the measurement of X-rays given off in prodigious amounts. The X-ray emissions from explosions, however, are in the same part of the electromagnetic spectrum as those from solar flares. Accordingly, to detect nuclear explosions, one must discriminate the effects against a background of solar X-rays. Other direct and indirect influences of the sun upon the earth will become more apparent as a deeper understanding of the sun and its phenomena is achieved through continuing observation and research. Current methods for studying the sun include ground-base observatories, rocket launched instruments, which are capable of high spectral and spatial resolution on a small scale and for short periods of time; and spacecraft such as the Orbiting Solar Observatories which carry unmanned solar instruments above the earth's atmosphere for extended periods of time. The ground-based observatories, even with the finest possible instruments and the advantages of direct control by astronomers, are limited in their observation of the sun and stars by the obscuring and filtering effects of the earth's atmosphere, MC 68-5072. The Apollo Telescope Mount is an advanced solar observatory in space that combines most of the advantages of space and ground observing locations. It places large sophisticated telescopes beyond the obscuring atmosphere, enabling them to make highly detailed observations of the sun over long periods. Procedures like those used with ground-based telescopes can be employed. With his ability to discern solar features of specific interest, an astronomer-Astronaut can react to significant events on the sun and can accurately point the Apollo Telescope Mount with minimum delay, acquiring data unachievable before. WHY STUDY THE SUN? EFFECT ON EARTH • SOURCE OF ALL AVAILABLE ENERGY • SOURCE OF EVERY FORM OF TERRESTRIAL LIFE •CONTROLS OUR ENVIRONMENT - ATMOSPHERE, CLIMATE, WEATHER • PRODUCES THE IONOSPHERE PERMITTING RADIO COMMUNICATION ONLY NEARBY STAR • PERMITS STUDY OF STELLAR ATMOSPHERES • PROVIDES PHOTOMETRIC AND SPECTROSCOPIC STANDARD FOR STELLAR WORK • ASTROPHYSICAL LABORATORY • COMBINATION OF VOLUMES, PRESSURES, TEMPERATURES NOT SCALABLE IN Three broad objectives of the Apollo Telescope Mount are: High resolution observations of the sun to increased knowledge of solar activity and its effects on the earth environment, ML 71-5276. Evaluation of the ability and desirability of man to operate complex scientific instruments in a space environment, ML 70-7503. Engineering and technological data for development of advanced astronomical systems, ML 70-7502. The instrumentation developed for observing solar phenomena at various wavelengths, Table 4, (ML 71-5111) fully exploits the advanced technology represented in the Apollo Telescope Mount. The experiment package can be pointed with a factor of ten accuracy improvement over the current Orbiting Solar Observatories. Temperature stabilization in conjunction with the improved pointing control system provides a stability and alignment capability never before achieved. The large size accommodates scientific instruments of approximately ten feet in length, permitting large focal lengths. Thus, Skylab allows operation similar to ground-based observatories utilizing fine pointing control and stability in direct response to man's judgment, but free of the limitations imposed by the earth's obscuring atmosphere. MATERIALS SCIENCE AND MANUFACTURING IN SPACE The weightlessness of orbital flight can be exploited by the novel manipulation of materials and altering the behavior of certain chemical and physical processes. For example, it is possible to melt material without physical contact. This has obvious applications in processing materials that are highly reactive or must be kept very pure, and in performing scientific experiments on fundamental aspects of solidification. The suppression of convection and buoyancy in fluids makes it possible to produce controlled temperature distributions in liquids and gases, to control the positions of particles or voids in liquids, and to produce heterogeneous compositions that do not mix except by diffusion. These effects offer a new dimension of control for experiments on the chemical and physical properties of fluids and a basis for a great many technical applications. Among these applications are the production of sophisticated composite materials, including materials with controlled distributions of voids, growth of large, highly perfect crystals from solutions and vapors, and methods for purifying materials as chemicals or biological compounds by separation through use of controlled fields. Materials processing experiments will demonstrate and aid in selecting the most promising products and processes for future exploitation. REPRESENTIVE SOLAR PHYSICS OBJECTIVES • ROLE OF MAGNETIC FIELDS IN THE HEAT AND MASS FLOW IN THE SUN'S ATMOSPHERE • DIFFERENCES OF HEAT AND MASS FLOW IN ACTIVE REGIONS COMPARED WITH "QUIET" REGIONS IN THE SUN'S ATMOSHERE AND RELATIONSHIP TO EVOLUTION OF ACTIVE REGIONS • FLARE NUCLEI AND THEIR ROLE IN THE EARLY EXPLOSIVE PHASE OF SOLAR FLARES • STORAGE OF HIGH EMERGY PARTICLES IN MAGNETIC FIELD CONFIGURATIONS ON THE SUN • EVOLUTION OF CORONAL STREAMERS AND THEIR RELATIONSHIP TO PROPAGATION OF DISTURBANCES FROM SUN TOWARDS EARTH NASA HQ ML71-5276 2-10-71 |