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

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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

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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

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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