Beyond the Atmosphere: Early Years of Space Science

[408] The evolution of the space science program furnished a good example of the scientific process in operation. Out of advancing technology came rockets and spacecraft which, even before they were developed, were envisioned as powerful scientific tools. As soon as large enough rockets were available, they were put to work in high-altitude research. When the space program was formally established, researchers working on problems of the atmosphere and space naturally gravitated to the new tools. The phrase space science came to mean scientific research made possible or significantly aided by rockets and spacecraft.
The rapid growth of research stemmed from the remarkable range of scientific disciplines to which rockets, satellites, and space probes could contribute. Although many space science results would have practical importance in such areas as meteorology, geodesy, aircraft and spacecraft design, communications, navigation, and earth-resource surveys, still the field was largely pure science, pursued primarily to advance man's knowledge and understanding of his universe. It is pertinent, then, to ask how space science affected science, particularly the disciplines to which it could best contribute.
Particularly noteworthy was the progress made in the earth and planetary sciences. Here the impact of space science was profound, generating a fruitful partnership among astronomers, physicists, and earth scientists. No longer was the geophysicist confined to a study of only one body of the solar system. No longer was the study of the planets solely a venture of the astronomers. The dearth of new data that had led planetary studies into the doldrums and even disrepute among astronomers, gave way to a sudden flood of new information that reawakened the astronomer's interest. Geophysical, geochemical, and geologic data on the moon and planets that poured in from astronauts and instrumented spacecraft-Explorers, Mariners, Pioneers, Rangers, Surveyors, and Lunar Orbiters-afforded earth scientists the opportunity to begin the serious development of a science of comparative planetology.
Equally exciting was progress in space astronomy, where rockets and satellites made possible the observation of the sun and the cosmos in wavelengths not observable at the ground. Inasmuch as current theories of the origin, evolution, and demise of celestial objects indicated that most of the [409] information on these objects would be manifested in the hitherto hidden wavelengths, rockets and satellites were in a position to make a tremendous contribution to astronomy, particularly in a period when there were many fundamental questions to answer in connection with phenomena such as radio and Seyfert galaxies, galactic nuclei, quasars, pulsars, neutron stars, and black holes in space. The expectations were borne out in the ultraviolet and x-ray measurements of the sun, and in the discovery and investigation of hundreds of x-ray sources in the sky. The solar observations produced a number of surprises, particularly the x-ray pictures showing considerable structure in the solar corona. As for celestial x-ray sources, they introduced a new field of high-energy astronomy which no one doubted would be intimately involved in answering important questions about fundamental processes in the universe.
As for the life sciences, the most significant results came from the manned spaceflight program, from biomedical studies that have not been dealt with in this book. With increasing productivity, Gemini, Apollo, and Skylab all contributed to an understanding of the effects of prolonged exposure to the space environment, particularly weightlessness, on human physiology and performance. In contrast, during the 1960s exobiology remained earthbound. No indigenous life was found on the moon, nor was any chemical evolution toward the formation of life found. Even in the mid-1970s, after two Viking landers failed to detect any evidence of life on Mars, the question of life on the Red Planet remained open.
Surveying what was accomplished in space science in its first decade and a half, it is clear that the rocket and spacecraft were revolutionary tools, making possible researches that could not have been carried out without them. Great quantities of valuable data flowed from space-borne instrumentation, and innumerable discoveries were made, greatly extending and enriching scientific paradigms in earth and planetary sciences and in astronomy. In the broadest terms, however, the paradigms of space science in the mid-1970s were compatible with those of the 1950s, in that no change in fundamental physical concepts and laws had been forced by the discoveries. From this point of view, then, the first decade and a half of space science was normal science.
But a more restrictive view is perhaps more appropriate. Within individual disciplines many scientists regarded space science as revolutionary. A case in point was the abandonment of what had previously been accepted as the basic hypothesis of geodesy, and the rise in importance of spherical harmonic techniques in the study of the earth's gravitational field. There were other minirevolutions. One was from the discovery of the earth's magnetosphere, not suspected beforehand, and the emergence of a new discipline of magnetospheric physics. Knowledge of the extensive evolution of the lunar surface after its formation produced a revolutionary change in the lunar paradigm. Perhaps, too, the discovery and characterization of [410] celestial x-ray sources, which had been missed in previous astrophysical theory, presaged a revolutionary change in astrophysical paradigms.