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International Space Station Earth Preservation and Space Exploration. Joseph Bermudez firstname.lastname@example.org December 15, 2009. ISS as the gateway to mankind’s continued exploration in space. Extend ISS support and scientific participation to all nations Define two main missions:
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December 15, 2009
(1) Earth environment - monitoring and analysis
(2) Space exploration - flexible mission training,
technology development, and equipment testing
(Maintain current ISS hardware – replace modular sections when required)
* as global, astronaut-tended Earth-monitoring node
* focus on global warming problem
* solar particle events
* galactic cosmic radiation
* passive (mass)
* active (magnetic field)
Effective for all radiation types
Highly dependent upon material selection and thickness for adequate protection
Requires a novel approach due to extreme energies of space radiation (e.g. lead causes secondary radiation)
dose in Sieverts = dose in Gray × RBE
RBE = relative biological effectiveness
thickness = (mass/area)/(mass/volume)
30 cSv annual dose limit applicable to 3 year mission
DENSE METALS (lead) - allow high energy particles collisions to create secondary radiation (neutrons and nuclear fragments)
LIGHT METALS (aluminum) - offer adequate shielding only at prohibitive mass penalty
CARBON FIBER (carbon)- provides adequate shielding at less mass penalty than aluminum
HIGH HYDROGEN CONTENT MATERIALS(liquid hydrogen, water, polyethylene) - provide optimum protection with minimum secondary radiation and lowest mass penalty
Material Density Neutron Absorption gamma
(kg/m^3) Cross-section (barns) (MeV)
Hydrogen 67.8 0.3326 2.223
Lithium 534 70.5 0.476
Boron 2080 767 0.478
Carbon 2267 0.0035 0.511
Aluminum 2700 0.232 1.809
( 1 barn = 1e-28 m^2)
lighter materials (carbon) may be matched to certain gamma radiation environments
Material Density LAC 1000*LAC/Density
(kg/m^3) (m^-1) (m^2/kg)
Water 1000 9.7 9.699
Carbon 2267 19.6 8.646
Aluminum 2700 22.7 8.407
Lead 11,340 164.0 14.46
(LAC = Linear Attenuation Coefficient, gamma)
Carbon fiber structure could serve a dual role as structural material and gamma shield.
* aluminum/borated aluminum
* carbon fiber nanotubes (hydrogen added)
* polyethylene (boron added)
* boron carbide (B4C)
Magnesium Whipple Shield (blue)
2 mm thick
Carbon Fiber Struts (gray)
Vectran Sheet (green)
Carbon Fiber Outer Wall (gray)
1 cm thick
Borated Polyethylene (red)
7.6 cm thick
Carbon Fiber Inner Wall (black)
10.5 cm thick
Hypothetical spacecraft serving both as a space station and an interplanetary spaceship
Demonstration project for application of the passive radiation shielded spacecraft wall
50 m radius rotating at 4 rpm to generate 1g equivalent
* Perimeter exercise track
* Exercise room
* Sick bay
* Agriculture (hydroponics)
ITEM MASS (kg) RATIONALE
Whipple Shield Bumper 39,124.4 micrometeoroids
Whipple Shield Stuffing 1,067.6 micrometeoroids
Whipple Shield Struts 1,000.0 micrometeoroids
Carbon Fiber Outer Wall 189,907.0 radiation
Borated Polyethylene Shield 751,716.0 radiation
Carbon Fiber Inner Wall 1,994,025.0 radiation/structural
Titanium Central Spokes 20,000.0 structural
TOTAL 2,996,840.0 kg
(compare to ISS completed mass of 471,736 kg)
5. Levy R, Sargent Janes G, Plasma Radiation Shielding, American Institute of Aeronautics and Astronautics, Vol. 2, No. 10, 1964, p. 1835-1838.
6. Levy R, Radiation Shielding of Space Vehicles by Means of Superconducting Coils, AVCO-Everett Research Laboratory, ARS Journal, (1961), p.1568-1570.
7. Goksel B, Rechenberg I, Surface Charged Smart Skin Technology for Heat Protection, Propulsion, and Radiation Screening, Institute of Bionics and Evolutiontechnique, TU Berlin, (2004), p. 1-7.
8. Shepard S G, Kress B T, Stormer theory applied to magnetic spacecraft shielding, Space Weather, Vol. 5, 2007, S04001, p. 1-9.
9. Schimmerling W, Overview of NASA’s Space Radiation Research Program, Gravitational and Space Biology Bulletin,16(2), June 2003, p. 5-10.
10. Radiation Protection: A Guide for Scientists, Regulators, and Physicians, Jacob Shapiro, (2002), Harvard University Press, p. 1-100.
11. Radiation Shielding, J Kenneth Shultis, Richard E Faw, (2000), American Nuclear Society.
12. Atoms, Radiation, and Radiation Protection, James E Turner, (2007),3rd Edition, Wiley VCH.
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