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

Possible SolutionsPossible Solutions

• Metal Walls

• Underground

• Water

• EM Shield

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

Copyright ©2001 AlphaMed Press

Goodsell, D. S. Oncologist 2001;6:298-299

Pyrimidine dimer (in violet) in DNA