Of all the problems contingent upon space flight it is doubtful if any
are more perplexing than the biological ones. In fact, it now appears
quite likely that the limiting factor on manned space exploration will
be less the nature of physical laws or the shortcoming of space vehicle
systems than the vulnerability of the human body.
In order to place humans in space for any extended period, we must solve
a host of highly complicated biological equations which demand intensive
basic research. The other side of the coin, however, is that when
scientific breakthroughs do occur in this area, they will probably be
among the most beneficial to come from the space program.
An idea of what is going on in the space medicine field can be obtained
from this summary:
Engineers already have equipped man with the vehicle for space
travel. Medical researchers now are investigating many factors
incident to the maintenance of space life--to make possible man's
flight into the depths of space. Placing man in a wholly new
environment requires knowledge far beyond our current grasp of
human biology.
Here are some of the problems under investigation: The
determination of man's reactions; the necessity of operating in a
completely closed system compatible with man's physiological
requirements (oxygen and carbon dioxide content, food, barometric
pressure, humidity and temperature control); explosive
decompression; psychophysiological difficulties of spatial
disorientation as a result of weightlessness; toxicology of
metabolites and propellants; effects of cosmic, solar, and nuclear
ionizing radiation and protective shielding and treatment; effects
on man's circulatory system from accelerative and decelerative g.
forces; the establishment of a thermoneutral range for man to exist
through preflight, flight, and reentry; regeneration of water and
food.[61]
In addition, intensive efforts are being brought to bear on such
problems as the effect on humans who are deprived of their sensory
perceptions, or whose sensory systems are overloaded, or who are exposed
to excessive boredom or anxiety or sense of unreality, or who must do
their job under hypnosis or hypothermia (cooling of warm-blooded
animals).
A recent space medicine symposium heard this theory advanced by a
prominent medical scholar:
Attractive, indeed, for the space traveler would be the choice of
hibernating during long periods when there was nothing he had to
do. With the increase of speeds and the lowering of metabolism,
consideration of flights running several hundred or even thousands
of years cannot be offhandedly dismissed as mere fantasy. During
prolonged flights of many months or years there will be very little
to see and that of negligible interest. The most practical way of
dealing with the problem might well be to have the pilot sleep 23
of the 24 hours.[62]
Lowering the body temperature would be one way of inducing the necessary
deep sleep.
Another possibility of handling some of the biological problems of space
flight, suggested by another physician, would be for astronauts to
discard the 24-hour Earth day and establish a longer rhythm for their
lives.[63]
At any rate, and while we may not now see just how it will come about,
knowledge gained from experiments such as these may result in important
medical and psychological advances.
In the drug and technological area of medicine, concrete benefits have
already resulted from the national space program. These include, as
already mentioned, a drug developed from a missile propellant to treat
mental ills, a means of rapidly lowering blood temperature in
operations, and a small efficient valve which could replace the valve in
a human heart.
Particularly gratifying, from the standpoint of medical value is the
Army's work toward an anti-radiation drug which could be taken before
exposure to reduce the biological effects of radiation.[64] Such a drug,
which is of special interest to astronauts who might be required to
subject themselves to varying belts of radiation, might be of even
greater use in the cause of civil defense.
A final and far-reaching phase of the health side of space exploration
deals with the basic nature of biology itself--how and under what
conditions life grows. Up to now biological science has been largely
"the rationalization of particular facts and we have had all too limited
a basis for the construction and testing of meaningful axioms to support
a theory of life."[65] Through research made possible by the space
program it may be possible to alter this condition. "The dynamics of
celestial bodies, as can be observed from the Earth, is the richest
inspiration for the generalization of our concepts of mass and energy
throughout the universe. The spectra of the stars likewise testify to
the universality of our concepts in chemistry. But biology has lacked
tools of such extension, and life until now has meant only terrestrial
life."[66]
[Illustration: FIGURE 13.--Biological reactions uncovered in
space medicine studies, such as this centrifuge experiment, may lead to
important health discoveries.]
The secrets which this research may divulge and their meaning for human
health can only be imagined. But they certainly would not be minor.