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Dose Predictions for Moon Astronauts ... We will be sending astronauts into space for Lunar and Martian exploration missions. ... NASA/NCRP goal is 3% Is ... – PowerPoint PPT presentation
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Title: Dose%20Predictions%20for%20Moon%20Astronauts
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Dose Predictions for Moon Astronauts
Nicholas Bachmann, Ian Rittersdorf Nuclear
Engineering and Radiological Sciences
Image Source www.astromax.com
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Premise lt- Abstract??
- We will be sending astronauts into space for
Lunar and Martian exploration missions. - The dose given to these astronauts is a big
concern to their safety.
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Cosmic Dose Sources
- Galactic Cosmic Rays (GCR)
- Solar Energetic Particles (SEP)
- Intrinsic Lunar Radiation
Image Source www.archives.gov
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Galactic Cosmic Rays
- Composition
- 85 protons
- 14 alpha particles
- 1 heavy nuclei
- Heavy nuclei are very dangerous because of the
energy they have (proportional to Z2) - Hard to measure precisely.
- Current Models are believed to be 25 accurate
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Solar Energetic Particles
- SEPs consist primarily of protons and alpha
particles.
- Are formed on active surfaces of the sun.
- Lower energy particles than GCRs
- Higher flux of particles than GCRs
Image Source www.nrl.navy.mil
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Solar Flares
- Solar flares emit considerable amounts of
radiation, up to tens of Gy. - Between Apollo 16 and 17 , one of the largest
solar flares ever recorded occurred. If the flare
had occurred during a mission even inside their
shielded spacecraft, the astronauts would have
absorbed lethal doses within 10 hours.
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Lunar Thorium Hotspots
- Because space suits protect well against a/ low
energy gamma, Th in the soil is not a major
concern - If any kind of space station were constructed on
the moon, radon would be a major concern if lunar
soil was used in cement
Image Source www.astronomy.com/asy/default.aspx?c
aid5357
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Apollo Mission Doses
- No significant difference between
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Nuclear Radiation from a Planetary Surface
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Effects on Health
- Worst-case scenario estimates an increase in
carcinogenic risk of 45 to interplanetary
astronauts. - NASA/NCRP goal is 3
- Is difficult to quantify due to the uncertainty
in the knowledge of the biological response of to
particles of various atomic numbers and energies.
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Conclusions
- Elevated or even fatal does to astronauts are
possible outside of Low Earth Orbit if proper
planning is not done - Radionuclides in the soil may be a concern for
lunar bases - Due to longer travel times, potential missions to
Mars would have to be ready for solar flares
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References
