¹ This section includes part of the Summary of the Panel on Radiation
Biology of the Environmental Biology Committee Space Science Board,
NAS/NRC (1963), and results of research by the Bioscience Programs,
NASA.
Radiation sources in space are of three types: galactic cosmic
radiation, Van Allen belts, and solar flares with an intense proton
flux. Cosmic radiation has higher energy levels than radiation produced
by manmade accelerators.
The Panel on Radiation Biology, while recognizing the need for
radiobiological studies of an applied nature with reference to manned
flight programs, stated that it would be shortsighted for the United
States to confine its efforts to the solution of immediate problems
since, in the long run, successful exploration of space will be aided by
the contributions of basic research. Both the immediate biological
research program and the continuing program for basic studies should be
built upon the large body of existing knowledge of radiation effects.
The attitude that all radiobiological experiments need be repeated in
the space environment should be resolutely rejected. Since fundamental
radiobiology cannot be performed easily in space, it has been
recommended that, wherever possible, these investigations be carried out
in ground laboratories in preference to flying laboratories.
Space environment does vary from the terrestrial environment, but the
variations are not so great as to lead to the expectation of strikingly
different biological effects of radiation in space. However, it is
conceivable that radiations whose effects are well known under
terrestrial conditions may have some unsuspected biological effects when
combined with unusual features of the space environment: e.g., zero g.
Previous space radiobiological studies have depended solely on very low
and inaccurately measured doses of ambient space radiation. It has been
difficult to distinguish between the observed response levels and the
random noise; thus, experiments have been inconclusive.