Space science radiation

National Academy of Sciences Space Science Board, Report of the Task Group on the Biological Effects of Space Radiation. Radiation Hazards to Crews on Interplanetary Mission National Academy of Sciences, Washington, DC, 1997. 

Since tracks caused by radiation damage are very stable, they can be investigated after very long periods of time. Many minerals contain a record of damage by fission products or cosmic rays that has been conserved over millions of years. This makes track detectors very valuable for geochemistry and space science. 

When considering how the evolution of life could have come about, the seeding of terrestrial life by extraterrestrial bacterial spores traveling through space (panspermia) deserves mention. Much is said about the possibility of some form of life on other planets, including Mars or more distant celestial bodies. Is it possible for some remnants of bacterial life, enclosed in a protective coat of rock dust, to have traveled enormous distances, staying dormant at the extremely low temperature of space and even surviving deadly radiation The spore may be neither alive nor completely dead, and even after billions of years it could have an infinitesimal chance to reach a planet where liquid water could restart its life. Is this science fiction or a real possibility We don t know. Around the turn of the twentieth century Svante Arrhenius (Nobel Prize in chemistry 1903) developed this theory in more detail. There was much recent excitement about claimed fossil bacterial remains in a Martian meteorite recovered from Antarctica (not since... 

Applied Sciences, Inc. has, in the past few years, used the fixed catalyst fiber to fabricate and analyze VGCF-reinforced composites which could be candidate materials for thermal management substrates in high density, high power electronic devices and space power system radiator fins and high performance applications such as plasma facing components in experimental nuclear fusion reactors. These composites include carbon/carbon (CC) composites, polymer matrix composites, and metal matrix composites (MMC). Measurements have been made of thermal conductivity, coefficient of thermal expansion (CTE), tensile strength, and tensile modulus. Representative results are described below. 

Moore (1998) suggested that the data available could be interpreted in terms of an ice crust 10-15 km thick. Christopher Chyba from the SETI Institute (Mountain View, California) has published articles in Nature (2000), the Proceedings of the National Academy of Sciences (2001a) and in Science (2001b) in which he suggests that a detailed study of this Jovian moon is necessary he discusses the possibility of a complex ecosystem, nourished by the radiation coming from outer space, on or in the ice layers of the moon. The planned Europa orbiter mission may provide certainty on this, but at least another five years of uncertainty lie ahead. The use of a submersible robot to study the (possible) ocean layer and its floor has been discussed. 

The architecture of macromolecules is another important synthetic variable. New materials with controlled branching sequences or stereoregularity provide tremendous opportunity for development. New polymerization catalysts and initiators for controlled free-radical polymerization are driving many new materials design, synthesis, and production capabilities. Combined with state-of-the-art characterization by probe microscopy, radiation scattering, and spectroscopy, the field of polymer science is poised for explosive development of novel and important materials. New classes of nonlinear structured polymeric materials have been invented, such as dendrimers. These structures have regularly spaced branch points beginning from a central point—like branches from a tree trunk. New struc-... 

Radiation is one area of science not well understood by the lay public, and often the media information relating to radioactivity is misleading and misunderstood. To some extent, the topics of radioactivity and radiation have become a political issue. The public is somewhat scientifically illiterate about radiation, and many people do not have a very clear understanding of the physical nature, sources, uses, benefits, and dangers of radiation and radioactivity. We can all learn more about radioactivity so that it can be used for the benefit of mankind without undue fear. After all, it is very natural and universal. Radioactivity takes place both inside and on the surface of our Earth. Not only does it exist in space, but it also is penetrating our bodies at all times from natural sources, and small amounts of radiation exist in our tissues and organs. It is part of all life. 

The kinetics data of the geminate ion recombination in irradiated liquid hydrocarbons obtained by the subpicosecond pulse radiolysis was analyzed by Monte Carlo simulation based on the diffusion in an electric field [77,81,82], The simulation data were convoluted by the response function and fitted to the experimental data. By transforming the time-dependent behavior of cation radicals to the distribution function of cation radical-electron distance, the time-dependent distribution was obtained. Subsequently, the relationship between the space resolution and the space distribution of ionic species was discussed. The space distribution of reactive intermediates produced by radiation is very important for advanced science and technology using ionizing radiation such as nanolithography and nanotechnology [77,82]. 

Strategic program plan for space radiation health research. Life Sciences Division, Office of Life and Microgravity Sciences and Application, NASA, Washington DC 20546. 

Sparrow E.M., Miller G.B., Jonsson V.K. (1962) Radiative effectiveness of annular-finned space radiators, including mutual irradiation between radiator elements. Journal of Aerospace Science 20(0), 1291-1299. 

Figure 1.17 An experimental set-up for electron spectrometry with synchrotron radiation which is well suited to angle-resolved measurements. A double-sector analyser and a monitor analyser are placed in a plane perpendicular to the direction of the photon beam and view the source volume Q. The double-sector analyser can be rotated around the direction of the photon beam thus changing the angle between the setting of the analyser and the electric field vector of linearly polarized incident photons. In this way an angle-dependent intensity as described by equ. (1.55a) can be recorded. The monitor analyser is at a fixed position in space and is used to provide a reference signal against which the signals from the rotatable analyser can be normalized. For all three analysers the trajectories of accepted electrons are indicated by the black areas which go from the source volume Q to the respective channeltron detectors. Reprinted from Nucl. Instr. Meth., A260, Derenbach et al, 258 (1987) with kind permission of Elsevier Science—NL, Sara Burgerhartstraat 25, 1055 KV Amsterdam, The Netherlands.

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