radiation dangers for a moon colony astr 8510, april 20, 2006 phillip mitchem
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Radiation Dangers for Radiation Dangers for a Moon Colonya Moon ColonyASTR 8510, April 20, 2006ASTR 8510, April 20, 2006
Phillip MitchemPhillip Mitchem
OverviewOverview
1. Types of Radiation
2. Effects of Radiation on You
3. Radiation Effecting a Moon Colony
4. Possible Solutions
5. Questions and References
Types of RadiationTypes of RadiationPhotonsPhotons
• Photons – UV– X-Rays– Gamma Rays
• Sources– Sun’s corona and
flares
Types of RadiationTypes of Radiation Baryons Baryons
• Baryons– Cosmic Rays (protons-89%, alpha-10%, iron,
silicon and carbon)– Neutrons
• Sources– Supernova, solar system, Sun’s corona and
flares– Moon Surface (Cosmic Rays)
A Few Radiation TermsA Few Radiation Terms
• Rad (Radiation Absorbed Dose)100 ergs of energy absorbed by 1 gram of tissue
• Rem (roentgen-equivalent man) = rad x Q
• Q (quality factor) the scaling factor
A Few Radiation Terms (cont.)A Few Radiation Terms (cont.)
• X-rays, Gamma Rays, Q~1
• Neutrons, Q=5
• Alpha particles, Q=20
Make it so, ToddGive him an A.
Radiation ExposuresRadiation Exposures
Source Amount (mrem/yr)
Cigarette smoking (Pb210 Po-210) 1300
Grand Central Station 525
Average annual 184
Cosmic radiation (31 mrem/yr Atlanta) 27
From our own bodies 25
Per dental x-ray 6
TV watching 1
Drinking a quart Gatorade a week (K-40) 0.2
Sleeping with significant other (K-40, C-14) 0.1
Effects of Radiation on YouEffects of Radiation on You
• Radiation sickness– Interferes with cell division (#1)– Reduction in red blood cells– Repress immune system– Redding of skin– Cataracts, lost of hair, bleeding– Genetic mutation– Cancer, death
Radiation Effecting a Moon ColonyRadiation Effecting a Moon Colony
• Moon more dangerous than Mars
• UV, X-Rays, Gamma Rays, Cosmic Rays and Neutrons
What is Known about the Radiation What is Known about the Radiation on the Moon?on the Moon?
• NOT A HELL OF A LOT!
Here’s What We Do KnowHere’s What We Do Know
• Cosmic Rays 0.6 millirads/hr on Moon
• Twice that at solar minimum
• 33 of 36 of the Apollo astronauts have cataracts caused by exposure to cosmic rays
Moon Radiations Data CollectedMoon Radiations Data Collected
• Average Radiation Doses of the Flight Crews
• Individual readings varied approximately 20 percent from the average
Apollo Mission
Dose, rads EVA Traverse, km
7 0.16 - -
8 0.16 - -
9 0.20 - -
10 0.48 - -
11 0.18 2.53 0.25
12 0.58 7.75 1.35
13 0.24 - -
14 1.14 9.38 3.45
15 0.30 19.13 27.9
16 0.51 20.23 27.0
17 0.55 22.07 35.0
Future MissionFuture MissionLunar Reconnaissance Orbiter Lunar Reconnaissance Orbiter
• Launch: Oct 2008
• CRaTER
• LEND
Lunar Exploration Neutron Detector Lunar Exploration Neutron Detector
• LEND’s Mission
• Create a global model of the neutron radiation on the Moon
Cosmic Ray Telescope for the Cosmic Ray Telescope for the Effects of Radiation Effects of Radiation
• CRaTER Misson
• Research the impact of the Moon’s radiation environment on biological systems
EM ShieldEM Shield
Questions and ReferencesQuestions and References
• Human Heredity" by Michael R Cummings (3rd ed.), West Publishing Company, St. Paul 1994. Chapter 12: Mutagens, Carcinogesn and Teratogens, Page 337
• Radiological Emergency Management, FEMA manual• The Oncologist Pyrimidine dimer in DNA, lttd at the Protein Data Bank• Radiation Protection and Instrumentation, J. Vernon Bailey, SP-368 Biomedical
Results of Apollo
Maximum DNA Repair Rates in Maximum DNA Repair Rates in Human CellsHuman Cells
Damage Normal Damage per hour Repairs per hour
Single-stranded breaks
2300-2880 2x10^5
Pyrimidine dimers
Noon-day sun
5x10^4
5x10^4