Chapter 31 -- The Human Body in Outer Space
"There is a more insidious and dangerous part of the space environment which must be studied extensively before humans can journey much beyond our immediate planetary system. Radiation occurs in several different forms.
One mystery which has not been solved yet is the missing white blood cells, the lymphocytes. When astronauts go into space the lymphocytes decrease. Where did they go? Do these blood cells decrease even more when a body stays longer in space? What are the implications for space voyages to Mars? Will the body be able to fight infections which may occur. Astronauts who have returned from space have had a tough time fighting infections due to lymphocyte depletions. This is one mystery which has far-reaching implications for long space flight.
Perhaps the most dangerous problem which the human body faces in space travel is radiation."
Pedemonte: Space Radiation Environment and its Biological Effects
Basically, a review, but definitely discussing the right stuff.
"Along with the long-term space exploration comes various potential health risks due to unique physical factors of the space environment. Space radiation is one of the primary environmental hazards associated with space flight. Crew members are subjected to greater amounts of natural radiation in space than they receive on Earth, which can result in immediate and long-term risks. The three major sources of radiation in space are the trapped belt radiation, the galactic cosmic rays (GCRs), and the solar particle events (SPEs)."
"the basic mechanism(s) of radiation carcinogenesis remains to be elucidated. Even less known are the effects of charged particles on normal tissues."
HUMANS IN SPACE*********good********
starts off with a list of bio-study areas,e.g.
http://www.jsc.nasa.gov/sa/sd/intro/immune.html "post-flight studies showed that the lymphocytes were not as effective in responding to challenges. However, astronauts have shown no increased susceptibility to disease, and lymphocyte counts returned to normal a few weeks after landing. In spite of this, the changes in the immune system must be understood and controlled, if possible, because such changes could have undesirable consequences on longer space missions."
but reveals some good "hard data" on exposures
Figure 1. Ionizing radiation hazards of space. GALACTIC COSMIC RAYS Hazardous and continuous Annual dose: 10 REM SOLAR WIND No hazard and continuous Protons, electrons, and other particles are low energy with a velocity of 500 km/sec SOLAR FLARE Very hazardous and intermittent but may persist for 1 to 2 days. High energy protons travel at the speed of light so there is no time to get under cover Protected dose 1O-100 REM/hr Unprotected dose Fatal Select here for more information about space radiation.mailto:firstname.lastname@example.org
Space Radiation Health Program*********good********
"The present volume is a collection of abstracts of radiation research sponsored by the NASA Space Radiation Health Program,
Humans engaged in space activities are exposed to extraterrestrial radiation, consisting of protons and heavier charged particles. Doses and dose rates typical of those caused by solar disturbances may impair crew performance whereas doses and dose rates typical of the galactic cosmic ray environment are likely to result in longer term effects, most notably an increase in the probability of cancer induction. The goal of the NASA Space Radiation Health Program is to establish the scientific basis for the radiation protection of humans in space. It supports scientific research into the fundamental mechanisms of radiation effects on living systems and the interaction of radiation with cells, tissues and organs, as well as the development of instruments and processes dealing with the measurement of radiation and its effects. In pursuit of the Space Radiation Health Program, the Life Sciences Division supports researchers at universities, NASA centers and national laboratories, establishes interagency agreements for cooperative use and development of facilities, and promotes international collaboration with similar organizations in other spacefaring nations. "
Primer on the Solar Space Environment :
You need to scroll way down the page, but then you'll find the dope:
"Skylab is an example of a spacecraft re-entering Earth's atmosphere prematurely as a result of higher-than-expected solar activity. During the great geomagnetic storm of March 1989, four of the Navy's navigational satellites had to be taken out of service for up to a week."
"Radiation Hazards to Humans
Intense solar flares release very-high-energy particles that can be as injurious to humans as the low-energy radiation from nuclear blasts. Earth's atmosphere and magnetosphere allow adequate protection for us on the ground, but astronauts in space are subject to potentially lethal dosages of radiation. The penetration of high-energy particles into living cells, measured as radiation dose, leads to chromosome damage and, potentially, cancer. Large doses can be fatal immediately. Solar protons with energies greater than 30 MeV are particularly hazardous. In October 1989, the Sun produced enough energetic particles that an astronaut on the Moon, wearing only a space suit and caught out in the brunt of the storm, would probably have died. (Astronauts who had time to gain safety in a shelter beneath moon soil would have absorbed only slight amounts of radiation.)
Solar proton events can also produce elevated radiation aboard supersonic aircraft fly ing at high altitudes over the polar caps. To minimize this risk, routine forecasts and alerts are sent through the FAA so that a flight in potential danger can alter its course and reduce altitude to minimize radiation exposure. "
"It has been realized and appreciated only in the last few decades that solar flares, CMEs, and magnetic storms affect people and their activities. The list of consequences grows in proportion to our dependence on technological systems. The subtleties of the interactions between Sun and Earth, and between solar particles and delicate instruments, have become factors that affect our well being. Thus there will be continued and intensified need for space environment services to address health, safety, and commercial needs. "
Space Radiation Risk Assessment
at Armstrong Laboratory
"The Delayed Effects Colony (DEC) of rhesus monkeys includes subjects exposed to low and intermediate doses of particulate radiations (of the sorts that are encountered in space or on polar flight routes) in the mid- to late 1960's. The DEC, declared a "national treasure" by a blue-ribbon review panel in 1989, continues to provide data on late radiation effects as it ages, and it is anticipated that the most valuable data from the survivors will be obtained in the years 1994-1997."
[R]adiation in Free Space
"Due the variability between events, the radiation dose accumulated due to solar protons may vary from negligible to well above lethal. The occurence of solar flares is basically not predictible and, thus, the warning period is only a few minutes to hours at best. The large fluxes associated with major solar flare events are potentially lethal to humans in space or on the surfaces of planets, moons, or asteroids."
Life Science Space Station Program at NASA:Space Radiation Health Program
"...emphasis on the establishment of a firm knowledge base to support future planetary exploration, and to predict the probabilities of deleterious health effects due to radiation exposure during human space activities. The emphasis of this program is on mechanistic studies with the potential to enable extrapolation of scientific research results to human beings in space."
http://bnlstb.bio.bnl.gov/www_root/webdocs/nasa/bkgd.html BETTER (but brief) leads to Joint NASA-BNL Project Background: "Knowledge of the biological effects of HZE ions has important implications for human exploration of space. The principal source of HZE ions in nature is galactic cosmic rays (GCR), which consist mostly of protons, with small components of helium and heavier nuclei, electrons and positrons. Although the GCR will be attenuated and fragmented by electromagnetic and nuclear interactions in shielding material, crew members will still be exposed to significant radiation from both primary and secondary nuclei. "
Mars Information Page - Radiation Protection
*%%%I think this document has been altered since I first discovered it!!! fortunately I downloaded a copy!!!! It used to be VERY VERY*good******MY Favorite????**
"Radiation Unknowns & Experiments: The effects of radiation on humans are not fully understood. For obvious reasons, experiments are not performed with humans and radiation. Data comes from experiments with controlled irradiation of cell cultures and nonhuman organisms. Much of our data for humans comes from analysis of Japanese atom-bomb survivors. There were also some classified experiments carried out by the U. S. Department of Defense in the early days of atomic weaponry. The Russians have a good amount of experience with the radiation effects of long-term spaceflight, but their space doctors do not have all the answers."
Space Studies Board Commission on Physical Sciences, Mathematics, and Applications National Research Council Radiation Hazards to Crews of Interplanetary Missions: Biological Issues and Research Strategies EXECUTIVE SUMMARY 1.INTRODUCTION Statement of Problem Contributions and Use of Past Radiation Research Current Understanding of Biological Effects of Radiation Types of Effects Effects Induced by Protons Effects Induced by Heavy Ions References 2.ISSUES OF CONCERN TO NASA: DISCUSSION AND CONCLUSIONS Types of Particles and Their Energies Galactic Cosmic Rays Solar Particles Secondary Particles Estimates of Uncertainty in Radiation Risk Factors Conclusions Biological Effects of Radiation Early Effects General Considerations Early Systemic Effects Skin Fertility Other Organ Systems Conclusions Late Effects General Considerations Cancer and Uncertainty in Estimates of Its Induction Central Nervous System Cataracts Heritable Effects Variation in Susceptibility to Radiation Across Subject Types DNA Repair Repair of Oxidative Damage and Double-Strand Breaks Other Studies Conclusion Loss of Research Programs References 3.HOW TO REDUCE RISK AND THE UNCERTAINTY IN RISK ESTIMATES
?!?o.k. not much info, just a web of terms, very few of which have actual definitions given, e.g.: "RADIATION DOSAGE RADIATION EFFECTS RADIATION HARDENING RADIATION HAZARDS RADIATION INJURIES " but gives a sense of the nexus of issues
"13 Medical, Psychological, and Social Considerations on a Lunar Base
13.2 Physiological Effects of the Space Environment on Humans
In any long-term space endeavor, human beings will invariably be the weak link in the chain. The human component of any manned space system is the one part that cannot redesigned by the engineer. Man has evolved over the past hundreds of millions of years in a terrestrial environment which provides gravity, atmospheric pressure, and relative safety from harmful solar and cosmic radiations. Only a small amount is known about the performance of the human machine in the space environment, and much more research is needed before many pressing questions can be answered in even a rudimentary fashion."
Elgra News number 19
"Question: According to you, which are the new findings in human physiology and pathophysiology (including biomechanics) obtained through space research? Answers: N° of quotations 1) Central venus pressure changes; blood volume shift; body 16 fluids and electrolytes changes; cardiovascular system in general; heart volumes/pressures 2) Vestibular and proprioceptive physiology; postural 13 adjustment; motor skill and control 3) Bone metabolism and redistribution; functional and 11 tructural changes in skeletal muscles and in myocardium 4) Physical performance; exercise, LBNP and other 8 countermeasure 5) Neurohormonal system; autonomic system balance; 8 circadian rhythm 6) Applications of telescience. New methods for 4 physiological monitoring 7) Improvement and/or amendment of human physiology 4 "classical" knowledge 8) Blood distribution in lung inhomogeneity; 4 ventilation/perfusion rate; respiratory mechanics; intrathoracic/intracardiac blood volumes similar to those standing at 1 g 9) Orthostatic mechanism, intolerance and prevention. 3 Bed rest physiopathology 10) Hypodinamics and physical unloading in space flight 3 11) Nervous and mental phenomena. Plasticity of sensory- 3 motor system 12) Cell division; embriogenesis and development of the 2 otholit system in microgravity 13) Decreased red cells mass 1 14) Plant growth 1 TABLE II Q uestion:Did they have or might have in the future any medical application? Answers: N° of quotations 1) No answer 11 "
how many impacts during EVA? space debris . . .
The Ultimate Space Debris Home Page
Russell D. Hoffman Discusses SPACE DEBRIS
Space Medicinehttp://www.marsacademy.com/med.htm**good**brief ... leads back to a real rah!! rah-mars travel site via the problems of creating and sustaining life in artificial gravity
A History of
the Space Radiation Effects (SPACERAD) Program
for the Joint USAF/NASA
Combined Release/Radiation Effects
Satellite (CRRES) Mission
Concerns effects on EQUIPMENT
"A second major issue in shielding is the "bremsstrahlung" effect. Laboratory tests have shown that when shielding for a system is increased beyond a certain point, the secondary radiation produced in the shielding by the primaries increases, actually leading to higher doses of the radiation. "
Space Life Sciences Data Archive at the NSSDC lots of cookies
shouldn't use this page but maybe there's some particular page . . .e.g.:
Master Catalogue: http://lsda.jsc.nasa.gov/nm.html
"Experiment Information" consists of drop down menues for searches:
This was the search on "radiation" but I'm not sure it can be linked successfully
Space Radiation Dosimetry Aboard Cosmos 1129: U.S. Portion of the Experiment (COS 1129-14)
for a 19 experiment:
RESULTS: The high-LET particles registered, given as Z spectra and LET spectra, were translated into rem dose as a function of LET. The total accumulated doses for the particles (LET > 100 keV/um) were 9.9 mrem inside and 25 mrem outside the spacecraft. The thermal, resonance, and high-energy neutron doses were found to be 0.52, 7.4, and 125 mrem, respectively, and the interior TLD dose was 347 mrad. The estimated error for this value is » 50% and results from an uncertainty in the correct background subtraction for the dosimeters due to an unexplained spurious irradiation of all the detectors.
Space Environment Effects and Interactions from Space Environment Effects Branch-LeRC, concerns effects on equipment! not humans
Space Rad. Shielding ***##o.k.?#***definitely indirect, if atall useful... Check it out again
SPACELINE INFOIf i only had a password . . . but could i hyper-ref it? dubious
Other Radiation Effects Links???too indirect. All links about radiation effects on equipment.
NO!Individual Exposure Takes Heat in Radiation StudyThis article seems to maintain the absurd proposition that we should eliminate on end of the curve in order to get a better statistical picture. The author argues that "radio-sensitive" people are skewing the curve.
Space Adaptation Syndrome Experimentsnot very good, just a few motion experiments
STS-78 Shuttle Launch Countdown Home Page
Life Science Experiments
Spacelab Life Sciences 2 (SLS-2)
The Astrobiology WebNO....
Radiation Physiology and Protectionnot very useful.....
Space Medicine and Human Factors ???
GROLIER'S: [DUBIOUS, as if safety could be assured
Should look for links to reports of the Challenger disaster, Apollo 1, Soyuz 11 . . .