-
Beyond the Atmosphere:
Early Years of Space Science
-
-
-
- CHAPTER 1
-
- SPACE SCIENCE
-
-
-
- [11] This book is
about space science. The subject is simple in concept, comprising
those scientific investigations made
possible or significantly aided by rockets, satellites, and space
probes. But in its realization
space science turns out to be very complex because of the
diversity of scientific investigations made possible by space
techniques.
-
- Interest in the phenomena of space is not
recent, its origins being lost in the shadows of antiquity.
Impelled by curiosity and a desire to understand, man has long
studied, charted, and debated the mysteries of the celestial
spheres. Out of this interest came eventually the revolution in
thought and outlook initiated by Copernicus, supported by the
remarkably precise measurements of Tycho Brahe, illuminated by the
observations of Galileo and the insights of Kepler, and given a
theoretical basis by Newton in his proposed law of gravitation.
The Copernican revolution continues to unfold today in human
thought and lies at the heart of modern astronomy and cosmology.
15
-
- Yet, until recently outer space was
inaccessible to man, and whatever was learned about the sun,
planets, and stars was obtained by often elaborate deductions from
observations of the radiations that reached the surface of the
earth. Nor were all the inaccessible reaches of space far away.
The ionosphere, important because of its role in radio
communications, was not as far away from the man on the ground
below as Baltimore is from Washington. Nevertheless, until the
advent of the large rocket, the ionosphere remained inaccessible
not only to man himself but even to his instruments. As a result
many of the conclusions about the upper atmosphere and the space
environment of the earth were quite tentative, being based on
highly indirect evidence and long chains of theoretical reasoning.
Time and again the theorist found himself struggling with a
plethora of possibilities that could be reduced in number only if
it were possible to make in situ measurements. Lacking the
measurements, the researcher was forced into guesswork and
speculation.
-
- Small wonder, then, that when large
rockets appeared they were soon put to work carrying scientific
instruments into the upper atmosphere for making the long-needed
in situ measurements. From the very start it was clear that the
large rocket brought with it numerous possibilities for aiding the
investigation and exploration of the atmosphere and space. It
could be instrumented to make measurements at high altitude and
fired along a vertical or nearly vertical trajectory for the
purpose, falling back to earth after reaching a peak altitude.
When so used the rocket became known as a sounding rocket or rocket sonde, and the operation was referred to as sounding the
upper atmosphere.
-
- A rocket could also be used to place an
instrumented capsule into orbit around the earth, where the
instruments could make extended-duration
[12] measurements of
the outer reaches of the earth's atmosphere or observations of the
sun and other celestial objects. Or the rocket might launch an
instrumented capsule on a trajectory that would take it far from
the earth into what was referred to as deep space, perhaps to
visit and make observations of the moon or another planet. The
orbiting capsules were called artificial
satellites of the earth; those sent farther out came to be
known as space probes
or deep space probes. Finally, the ultimate possibility of carrying men
away from the earth to travel through deep space and someday to
visit other planets emphasized dramatically the new power that men
had acquired in the creation of the large rocket.
-
- A language of rocketry emerged, which the
news media popularized. Familiar words took on new meanings, and
new terms were encountered: artificial satellite, spacecraft,
space launch vehicle, rocket stages, countdown, liftoff,
trajectory, orbit, tracking, telemetering, guidance and control,
retrorockets, reentry-and space science.
-
- Through all the centuries of scientific
interest in space phenomena, the phrase space science had not
gained common use. That the terminology did not come into use
until after rockets and satellites brought it forth gives force to
the definition of space science given at the start of this
section. That definition sets forth the meaning in mind when in
June 1957 the U.S. National Academy of Sciences combined the
functions of the IGY Technical Panel on Rocketry and the IGY
Technical Panel on the Earth Satellite Program into a single
board, naming it the Space Science Board. That is the meaning
implied by the discussions in the first book-length publication by
the Space Science Board a few years later.16 That is the meaning picked up by Samuel Glasstone
in 1965 in his comprehensive survey of space science:
-
- The space sciences may be defined as those
areas of science to which new knowledge can be contributed by
means of space vehicles, i.e., sounding rockets, satellites, and
lunar and planetary probes, either manned or unmanned. Thus space
science does not constitute a new science but represents an
important extension of the frontiers of such existing sciences as
astronomy, biology, geodesy, and the physics and chemistry of
Earth and its environment and of the celestial bodies.
17
-
- While the basic meaning of space science
was clear and unvarying from the start, the exact nature of the
activity, and in particular its relationship to the rest of
science, was not always so clear. Glasstone's use in the above
quotation of space sciences
in one place and space science in the
very next sentence reflects one question that arose often during
the first years of the NASA program. Is space science a new
scientific discipline* or, if not yet, [13] will it in time
develop into a new discipline? The question arose primarily
because of the pure-science character of space science and the
strong coherence that quickly developed in the field, but also
because of the broad range of scientific topics to which research
was addressed. The initial answer to the question generally agreed
to by those in the program was that given by Glasstone: space
science was not a new discipline and should not be expected to
become one. The initial response was probably intuitive, but in
retrospect it is seen to have been the correct answer.
-
- Space science makes extensive
contributions to geophysics; but this part of space science
remains a part of the discipline of geophysics, using its
techniques and instrumentation and employing and extending its
basic theory-sharing its paradigm, that is. The researchers using
space techniques for geophysical investigations, while perhaps
thinking of themselves as space scientists, continue to call
themselves geophysicists, to be members of geophysical societies
like the American Geophysical Union, to present their papers at
geophysical meetings and to publish them in geophysical
journals.
-
- Space science also makes numerous
contributions to astronomy, but again the parts of space science
devoted to astronomy remain a part of the discipline of astronomy,
and space scientists using rockets for astronomical research
continue to view themselves as astronomers. Their results are
presented at meetings like those of the American Astronomical
Society or the International Astronomical
Union** and are published in their journals or
proceedings.
-
- Cosmic ray physicists find space methods
advantageous in many of their researches, but continue to be
cosmic ray physicists first and space scientists only
incidentally. Examples can be multiplied at length.
-
- Nevertheless, for several years following
Sputnik the thought that space science might evolve into a
separate discipline persisted. One can understand why. The demands
imposed by rockets and spacecraft on the running of a science
program were severe, giving a coherence to the field akin to that
characteristic of a scientific discipline. But rockets and
spacecraft did not rest upon or stem from the scientific
disciplines they served. Rather, they were simply trucks to
provide transportation to otherwise inaccessible places, while the
genuine techniques and instrumentation of the investigations were
those of the individual disciplines that benefited from the new
means of transportation.
-
- To emphasize the diverse scientific
disciplines, writers sometimes chose to use the phrase
space sciences . At other times authors used science in space
[14]
to imply that space science was not separate from science on the
ground and was neither more nor less than the familiar, everyday
science carried out in a new arena. These initial uncertainties
were reflected in the changing names given to the space science
group in NASA Headquarters by the author and his colleagues. In
1958 and 1959 the division in the Office of Space Flight
Development that had responsibility for scientific research in
space was labeled Space Science. When NASA Headquarters
reorganized under the new administrator, James E. Webb, the space
science program was elevated to the level of a separate office,
which called attention to the plural nature of its activity in its
title: Office of Space Sciences. Finally, in the reorganization of
1963 that brought science and applications together under one
head, NASA settled on space science
as its choice for the rest of the
1960s, designating the new entity as the Office of Space Science
and Applications. 18
-
- If space science had been distinctly
separate from the rest of science, NASA might well have felt less
impelled to draw in the wide participation that the agency
encouraged in the program. As it was, recognizing that no single
agency could reasonably expect to bring within its own halls the
expertise needed for all the separate disciplines, NASA
consciously sought broad participation from the outside scientific
community, especially from the universities, where the greatest
interest in pure science was to be found.
-
- Within the universities the question arose
in a somewhat different form. As the numbers of those entering
space science research grew apace, a need to provide training for
new scientists who might wish to pursue space research as a career
became evident. Should this be done by setting up departments of
space science in universities? The instinct of NASA program
managers was not to do so, and when asked they advised against it,
recommending instead that opportunities be provided within the
traditional departments of astronomy, physics, geophysics,
geology, etc., for taking on space-related problems as thesis
topics. Most universities saw it this way, although a few decided
to experiment with separate space science
departments.***
-
- The inseparability of space science from
the rest of science and the broad range of disciplines to which
space techniques promised to contribute gave impetus to the rapid
development of science in the national space program. It must be
emphasized that scientists came into the program with problems
that had been under attack by other methods and that appeared to
need some new approach if they were to be solved. The promise to
provide that new approach drew researchers first to sounding
rockets and later to satellites and space probes.
-
- [15] Writing about six
years after the start of sounding rocket research in the United
States, in what was probably the first book devoted to the
subject, the author was able to find in the scientific literature
significant results to report on upper atmospheric pressures,
temperatures, and densities; atmospheric composition; solar
radiations in the ultraviolet and x-rays; upper-air winds; the
ionosphere and the earth's magnetic field; cosmic rays; and
high-altitude photography. A year later the list was extended even
further in a book reporting the papers presented at the first
international conference on the subject of high-altitude rocket
research, arranged by the Upper Atmosphere Rocket Research Panel
(see chap.
4) of the United States and the
Gassiot Committee of the Royal Society of
London.19 In 1956, just a decade after the start of rocket
sounding of the upper atmosphere, the Upper Atmosphere Rocket
Research Panel, extrapolating from its sounding rocket experience,
turned its attention to the researches that would be possible with
instrumented satellites of the earth. These deliberations were
published in the first book on the subject to be assembled by
persons professionally engaged in high-altitude research.
20 To the research topics listed above, the book added
some new ones: meteors and interplanetary dust, particle
radiations from the sun, the aurora, stellar astronomy,
meteorology, and geodesy. The potential contributions to science
of both manned and unmanned spacecraft were discussed in the Space
Science Board's first book. While most attention was devoted to
unmanned exploration of space, the ultimate potential of manned
spaceflight was recognized in such words as: "The significant and
exciting role of man lies in the exploration of the Moon and
planets." 21
-
- Such scientific investigations, made
possible by sounding rockets and spacecraft, came to define what
is meant by space science. Much of the potential of space science
was already discernible before ever a satellite had been launched,
and by the end of 1960-by which time the first NASA administrator,
Keith Glennan, had set the agency firmly on its course-the broad
sweep of space science was fully apparent. By the end of a decade
space science research had become worldwide, and a steady flow of
results was pouring into the literature. 22
-
-
- * A scientific discipline is an area of scientific
investigation in which the investigators share a common paradigm
or group of paradigms, embracing a common body of theory, and
techniques and often instrumentation that stem from the underlying
theoretical basis of the discipline.
-
- **
Although much, probably most,
of the space science research on the moon and planets falls into
the disciplines of geophysics and geochemistry, the Planetary
Sciences Division of AAS and Commission 16 (Planets) and
Commission 17 (Moon)- in 1979 merged as new Commission 16- of the
IAU have maintained a vigorous interest in these aspects of space
science research.
-
- ***
One successful experiment was
the Department of Space Sciences set up by Rice University under
the direction of a young theoretical physicist, Dr. Alexander
Dessler, who had done considerable research on the newly
discovered terrestial magnetosphere and who for some years served
the American Geophysical Union as editor of the space sciences
section of the Journal of Geophysical Research.
-
-
-


-