_Foreword_
This volume is one of a series which summarize the progress made during
the period 1958 through 1964 in discipline areas covered by the Space
Science and Applications Program of the United States. In this way, the
contribution made by the National Aeronautics and Space Administration
is highlighted against the background of overall progress in each
discipline. Succeeding issues will document the results from later
years.
The initial issue of this series appears in 10 volumes (NASA Special
Publications 91 to 100) which describe the achievements in the following
areas: Astronomy, Bioscience, Communications and Navigation, Geodesy,
Ionospheres and Radio Physics, Meteorology, Particles and Fields,
Planetary Atmospheres, Planetology, and Solar Physics.
Although we do not here attempt to name those who have contributed to
our program during these first 6 years, both in the experimental and
theoretical research and in the analysis, compilation, and reporting of
results, nevertheless we wish to acknowledge all the contributions to a
very fruitful program in which this country may take justifiable pride.
_Homer E. Newell_
_Associate Administrator for_
_Space Science and Applications, NASA_
_Preface_
This summary of certain aspects of the space biology program of the
National Aeronautics and Space Administration brings together some
results of NASA research and NASA-sponsored research under grants and
contracts from 1958 through 1964. Closely related research even though
not sponsored by NASA is also included.
The space biology program has had a late start in comparison with the
space physics program, and only a token program existed before 1962.
Much of the present research involves preparation of space-flight
experiments and obtainment of adequate baseline information. Perhaps
half the research results reported are derived from the NASA program.
Additional information is included from many other sources, especially
the U.S. Air Force with its long history of work in aviation and
aerospace medicine.
Relatively few biological space-flight experiments have been undertaken.
These have been to test life-support systems and to demonstrate, before
manned space flight, an animal’s capability to survive. Few critical
biological experiments have been placed in orbit by NASA, but a
biosatellite program will soon make a detailed study of the fundamental
biological effects of weightlessness, biorhythms, and radiation.
The search for extraterrestrial life has been limited to ground-based
research and planning for planetary and lunar landings. Life-detection
experiments have been developed and tested, and an important and
exciting program is being planned to detect and study extraterrestrial
life, if it exists.
Interest in space biology has been slow in developing, and there has
been some caution and controversy in the scientific community. However,
increased interest is starting to push forward the frontier of this new
and important scientific field, and future outlook appears to be
optimistic.
This summary was written and compiled by the members of the Bioscience
Programs Division of the Office of Space Science and Applications. The
report was edited and chapters 1, 3, 6, and 7 were written by Dale W.
Jenkins, Chief, Environmental Biology; chapter 2, by Gregg Mamikunian,
Staff Scientist, Exobiology; chapters 4 and 8, by Richard E. Belleville,
Chief, Behavioral Biology; and chapter 5, by George J. Jacobs, Chief,
Physical Biology.
_Contents_
page
1 BACKGROUND ................................................... 1
2 EXOBIOLOGY ................................................... 5
3 ENVIRONMENTAL BIOLOGY ........................................ 23
4 BEHAVIORAL BIOLOGY ........................................... 43
5 MOLECULAR BIOLOGY AND BIOINSTRUMENTATION ..................... 57
6 FLIGHT PROGRAMS .............................................. 65
7 MANNED SPACE FLIGHT .......................................... 77
8 SIGNIFICANCE OF THE ACHIEVEMENTS ............................. 111
REFERENCES ..................................................... 119
chapter 1
_Background_
The biological program of the National Aeronautics and Space
Administration had a late start. A small life sciences group, organized
in 1958, was concerned with life support and use of primates for system
and vehicle testing for the Mercury program. Three small suborbital
flights of biological materials were flown in space.
The Bioscience Program Office of the Office of Space Science and
Applications was organized in 1962. The goals of the Bioscience Program
are: (1) to determine if extraterrestrial life exists anywhere in the
solar system and to study its origin, nature, and level of development,
if it is present; (2) to determine the effects of space and planetary
environments on Earth organisms, including man; (3) to conduct
biological research to develop life support and protective measures for
extended manned space flight; and (4) to develop fundamental theories in
biology relative to origin, development, and relationship to
environment. Research and development has been carried out to design
life-detection experiments and instruments for future flights to Mars
and to develop experiments to study the effects of the space environment
on living organisms. A biosatellite program, started in 1963, has the
first of six flights scheduled for 1966.
Space exploration has demanded a rigorous development, especially in the
biosciences area. Investigation of the solar system for exotic life
forms, the environmental extremes to which Earth organisms (including
man) are being exposed, the possibilities for modification of planetary
environments by biological techniques yet to be developed, and the
problems of communication in biosystems are areas which have required
refinement of the theoretical framework of biology before progress could
be made rapidly enough to keep pace with technological advances in
transportation.
Of all the sciences, biology alone has not yet benefited from
comparisons with the universe beyond Earth. It is reasonable to suppose
that breakthroughs might be made in biology on the basis of comparisons
with life from other worlds. Organisms elsewhere may have found
alternatives to processes we think of as basic characteristics of life.
In contrast, physical science has advanced sufficiently to provide a
great body of laws which may be expressed in mathematical terms, and by
which phenomena may be predicted with complete accuracy. A well-known
characteristic of biological phenomena is variability. The Darwinian
concept of evolution is perhaps the only pervading generalization in
biology. This concept has been supported by evidence of a hereditary
mechanism in the discovery of genes and gene mutations.
Space bioscience represents the convergence of main disciplines with a
single orientation, whose direction is determined by the problems of
manned space travel which have, in turn, created a host of
bioengineering problems concerned with supporting man in space.
Foremost among these questions is the possibility of the existence of
extraterrestrial life. The field which is concerned with the search for
extraterrestrial life has come to be called "exobiology." In addition to
the challenge of great technological problems which must be solved,
exobiology is so closely related to the central scientific questions in
biological science that it is considered by some to be the most
significant pursuit in all of science.
One of the major opportunities already presented by the advances in
propulsion systems is the ability to escape from the influence of the
Earth, which has made possible the study of organism-environment
relationships, particularly the role that environmental stimuli play in
the establishment and maintenance of normal organization in living
systems.
Transcending even these formidable objectives of space bioscience is an
objective shared by all life sciences, the discovery of nature’s scheme
for coding the messages contained in biological molecules.
Extraterrestrial biology seeks to find not only evidence of life now
present, but the vestigial chemicals of its previous existence. The ways
and means have already been made available to study molecules on whose
long, recorded messages is written the autobiography of evolution—the
history of living organisms extending back to the beginnings of life. On
this same basis, it is now within the realm of science to foresee the
means of predicting the development of life from primordial, nonliving
chemical systems. Closely allied to the search for extraterrestrial life
is research which seeks to identify the materials and the conditions
which are the prerequisites of life.
Space bioscience research is now extending human knowledge of
fundamental biological phenomena, both in space and on Earth, just as
the physical sciences explore other aspects of the universe. The
accomplishment of bioscience objectives is totally dependent upon
advances in the technology of space flight. A highly developed
launch-vehicle capability is essential to accomplish the long-duration
missions required in the search for extraterrestrial life.
Life on other planets in the solar system (with emphasis on Mars) will
be investigated by full exploitation of space technology which will
allow both remote (orbiter) and direct (lander) observations of the
planetary atmosphere, surface, and subsurface. Certain characteristics
of terrestrial life, such as growth and reproduction, provide a basis
for relatively simple experiments which may be used on early missions to
detect the existence of life on Mars. Later missions will provide
extensive automatic laboratory capabilities for analyzing many samples
taken from various depths and locations. Because of the hypothetical
nature of current experiment designs, it is likely that visual
observations of the planet will be required. Many technical problems are
involved in storing and transmitting the large amounts of data over
planetary distances. Such visual observations might very well be crucial
in interpreting results from other experiments. Critical to all
exploration of the Moon and planets are the requirements to: (1) prevent
contamination of the environment with Earth organisms and preserve the
existing conditions of the planet for biological exploration; (2)
provide strict quarantine for anything returned to Earth from the Moon
and planets.
The biological exploration of Mars is a scientific undertaking of the
greatest significance. Its realization will be a major milestone in the
history of human achievement. The characterization of life, if present,
and study of the evolutionary processes involved and their relationship
to the evolution of terrestrial life would have a great scientific and
philosophical impact. What is at stake is nothing less than knowledge of
our place in nature.
Extended Earth orbital flights with subhuman specimens will be used to
determine the effects on Earth organisms of prolonged weightlessness,
radiation, and removal from the influence of the Earth’s rotation. Such
flights of biosatellites and other suitable spacecraft are expected to:
(1) establish biological specifications for extending the duration of
manned space flight; (2) provide a flexible means of testing unforeseen
contingencies, thus providing an effective biological backup for manned
missions; (3) yield experimental data more rapidly by virtue of the
greater number and expendability of subjects; (4) anticipate possible
delayed effects appearing in later life or in subsequent generations,
through use of animal subjects with more rapid development and aging;
(5) develop and test new physiological instrumentation techniques,
surgical preparations, prophylactic techniques, and therapeutic
procedures which are not possible on human subjects; and (6) provide a
broad background of experience and data which will permit more accurate
interpretations of observed effects of space flight on living organisms,
including man.
chapter 2
_Exobiology_
The possibility of discovering an independent life form on a planet
other than Earth presents an unequaled challenge in the history of
scientific search. Therefore, the detection of life within the solar
system is a major objective of space research in the foreseeable future.
The scientific data presently available concerning the possible
existence of a Martian life form and the chemical constitution of the
surface of Mars are disappointingly few. In fact, it is impossible to
make a statement about any of the many surface features, other than the
polar caps, with any degree of certainty. The observational results have
been accounted for by many conflicting hypotheses which can only be
resolved by the accumulation of new evidence.
The arguments supporting the existence of Martian life ([ref.1]) are
based on the following observations:
(1) The various colors, including green, exhibited by the dark areas
(2) The seasonal changes in the visual albedo and polarization of the
dark areas
(3) The ability of the dark areas to regenerate after an extensive
"duststorm"
(4) The presence of absorption bands at 3.3µ-3.7µ, attributed to
organic molecules
Conflicting interpretations of the above observations have been
advanced. The argument based on the colors is inconclusive, and several
workers have suggested that the color is a contrast effect with the
bright-reddish continents. The meager quantitative data have been
discussed by Öpik ([ref.2]) who has reduced Kozyrev’s photometric
observations of the very dark area of Syrtis Major to intrinsic
reflectivities by allowing for the estimated atmospheric attenuation and
reflectivity. Kuiper ([ref.3]) similarly demonstrated the absence of the
near-infrared reflection maximum, which is characteristic of most green
plants, indicating that chlorophyll was not responsible for the color.
The second and third arguments remain the most cogent. However, serious
limitations are imposed on the second if the severity of the Martian
climate is considered. Föcas ([ref.4]) has photometrically measured the
seasonal changes in the fine structure of the dark areas of Mars and
concludes that—
(1) The dark areas of Mars show periodic variation of intensity
following the cycle of the darkening element
(2) The average intensity of the dark area, not including the action
of the darkening waves, increases from the poles toward the
equator
(3) The action of each of the darkening waves decreases from the poles
toward the equator. This decrease is balanced in the equatorial
zone by the combined action of the two darkening waves alternately
originating at the two poles. The mechanism of the
darkness-generating element seems to be constant for all latitudes
during the Martian year.
The variation in intensity has been explained recently by nonlife
mechanisms for Depressio Hellespontica (an area showing one of the
greatest seasonal changes) ([ref.2]). Similar nonlife mechanisms may be
applicable to the other dark regions, and, thus, the "darkening" can be
used only as circumstantial evidence in support of a Martian life form.
If inorganic interpretations of the seasonal albedo variation are
accepted, then an inorganic interpretation must also be advanced for the
polarization variation. Two possibilities can be suggested:
(1) A change in surface texture, caused by varying absorption of
atmospheric constituents, causing both the albedo and polarization
to change in the manner observed
(2) A change in surface texture, in which the surface material becomes
rougher, which also explains the observed polarization data
([ref.5])
The third argument against the regenerative feature of the dark areas
being a life process has been advanced by Kuiper ([ref.6]). It is based
on atmospheric circulation causing dust, presumably lava, to be blown on
the dark areas of Mars during the late summer, autumn, and winter, and
then removed during the spring. Mamikunian and Moore have recently
advanced the similar explanation that carbonaceous chondrites or
asteroidal matter may induce the observed phenomenon if they are
abundant on the planet’s surface. The pulverized chondritic material
will exhibit a high degree of opacity due to localization and, hence, a
change in polarization characteristics and a decrease in polarization
following mixing of the chondritic material with indigenous surface
minerals.
The fourth observational argument, the Sinton bands ([ref.7]), has been
shown to be at least doubtful. Rea, Belsky, and Calvin ([ref.8])
recorded infrared reflection spectra for a large number of inorganic and
organic samples, including minerals and biological specimens, for the
purpose of interpreting the 3µ-to-1µ spectrum of Mars. These authors
state that a previous suggestion that the Martian "bands" be attributed
solely to carbohydrates is not a required conclusion. At the same time
they fail to present a satisfactory alternate explanation, and the
problem remains unsolved. More recently, Rea et al. ([ref.9]) noted the
similarity between the 3.58µ and 3.69µ minima in the Martian infrared
spectra and those of D₂O-HDO-H₂O mixtures and, particularly, of HDO.
With all this marked disagreement in interpreting the observational data
concerning Mars, it becomes clearly evident that an experimental
approach to the detection of life on Mars should provide the maximum
positive information possible. Some life-detection experiments developed
with NASA support have been summarized by Quimby ([ref.10]).
The schema of the biological exploration of a planet is to conduct a
series of complementary experiments proceeding from general to specific.
The general experiments will examine gross characteristics of the
planet’s environment and surface for determining the probability of an
active biota (life). Data from the general experiments will be
significant in—
(1) Defining the nature of specific experiments in which life
detection is the major objective; and
(2) Providing a high degree of confidence in undertaking specific
experiments, since indications from the gross characterization of
the planet in question will influence the choice and design of the
specific experiments.
The biological exploration of planets is then to be defined as the
search for those parameters relevant to the origin, development,
sustenance, and degradation of life in a planetary environment. This
definition will give rise to a critical question for each progressively
specific and complex experiment to determine—
(1) The existence of life on the planet
(2) The degree of similarity or dissimilarity (structure and function)
with respect to terrestrial life
(3) The origin of this planetary life
The immediate objective of the biological explorations of the planet is
to define the state of the planetary surface, which may exhibit the
following properties:
(1) A prebiota (defined as the absence of life)
(2) An active biota (defined as the presence of life)
(3) An extinct biota (defined as evidence of former life)
The identification and the detailed characterization of each of the
above stages of planetary development constitute the subject matter of
the biological exploration of the planets and, specifically, Mars.