Frank Cucinotta, JSC ra

Please describe the radiation environment in these places:

?) three sources GCR, biggest threat protons to iron nuclei, iron is the
end of what's appreciable, all different energy (eV 100s of GeV)
aluminum or tissue 100s to 1000s of centimeters; solar particle events,
unpredictable, these occur at solar max, flares are x-ray events, CMEs
give us solar protons, varies from event to event, usually their enery
is small, not high enough to penetrate; trapped radiation in the Van
Allen belts.

Rad energy/mass, rem is conversion using the RBE, when we give a number
for a rem it's a guess. Once a committee conversion factor is a guess.

GCR annually 30 to 60 rem, heavily shielded. More so than Apollo. (Space
station 1/3, 1/3 from Earth, another third, lower energy shielding from
B; Mars gets about ½ the rate from deep space; Moon is ½)

Solar flares: one of the largest, 8 hours of vulnerability, 5 rem on the
ISS; on the way to the moon: with little shielding you could get 100
rem, in a storm shelter know it down to 20 rem. Aluminum shielding;

Near-Earth (what about the van Allen Belts)

Cruising to the Moon

On the Moon, a moonbase

Cruising to Mars

On Mars, a Mars base

Land on ice is better than landing on regolist; critical precursor needs
is a radiation detector on Mars to understand the neutron environment.
Predicted to be 25% of rem; reduce that by half. Altitude of the landing
site; 20 rem lower to 30 rem at the highest point;

MOON: neutrons are less important because the relative contribution is
smaller; no atmosphere;

What are the energy ranges of concern to astronauts? LET linear energy
transfer, high LET is the most 100 keV per micron 50 to 200 keV per
micron have the maximum biological effect. Dead cells are better than
damaged cells. Overkill:

Lay out the health effects of unprotected spaceflight to the Moon or
Mars;

We would expect like as much as 5% increase in fatal cancer; early 40's
twice that for a female;

MARS: 15% to 20%; have to understand the biology of how these radiations
cause cancer; we've been doing NSRL Brookhaven Nasa Space Radiation Lab
(July 2003, opened in October, first set of experiments in Oct/Nov, NASA
provides research funding, partnerships with the DoE, 9 pi's are jointly
funded with NASA, infrastructure from Brookhaven); that guives us a much
better capability to simulate space radiation; 5 fold improvement in
research capability; under There's a host of models, take a human cell,
mouse, rats, look at DNA damage, part of the strategy, is what would
happen to x-rays and gamma-rays; expose lower species like mouse or
rats; tissue matrix, look at interactions between cells, 3D cell
culture; Our goal is by 2015 to have them +- 50%; pick a crew and
shielding;

MATERIALS: It will never be like a plane flight on Earth; This is the
guy who's going to put us out of business; large tanks of hydrogen
surrounding the spacecraft; takes away the space radiation problem;
shielding solution; polyethelene (C 2H) or water shiwlding doesn't
solave the problem; magnetic shielding is pie in the sky;

Areal density, actual thickness \* material density; H tank 10 g cm\^2,
about a meter in actual thickness (attenuate down to 75%). Polyethelene,
10 g cm\^2, 4 to 6 inces thick (), more than 4 inches ; aluminum half;

Earth: 0.2 rem (diff kind of rad); 0.5 rem REPAIR PATHWAYS:

Free space: 120 rem (annual)

Aluminum: 65 rem (annual)

Water, polyethelene: 50 rem

Liquid H2: 25 rem

Franklin Chang Diaz: GCR you

Aluminum structures with local shielding of polyethelene; carbon
composites with hydrogen inside; SPACE STATION: you have this magnetic
field protects you a great deal, two places: near the center of the
service module, also inside the lab module crew quarter has some
polyethelene; 60 to 70% variation from high to ;

We wouldn't know for sure what would happen; it would be higher than for
low Earth orbit; 3% increase increase for ISS; 5% for Mars 5 times
lower;

Solar fare 1000 rem, no shielding

Read super spaceships, phantom torso

Van Allen belt contains electrons and protons with energies \> 10 MeV.
It peaks about 1 Earth radius above Earth's surface. There is also a
weaker inner belt, populated with interstellar cosmic rays, and a weak
outer belt with E \< 10 MeV.

What is a rem? Sudden doses of 300 or so rem will make you very sick,
maybe even kill you. But you can get 300 rem spread out over a number of
months or years with little effect. Spreading the dose gives the body
time to recover, to repair cell damage. A sudden dose less than 75 rem
will not make you sick.

Cosmic rays: 35 rem per year en route to Mars, 5 to 10 rem per year on
Mars.

Here in Aspendell I get 0.3 rem per year. A lifetime living here would
equal a trip to Mars.

A big solar flare might deliver 30 to 50 rem, suddenly, to an stronaut
in an Apollo-style craft.

2 rem flying through the van Allen belts for a couple of hours? (How
many rem do astronauts get when the ISS goes through the SAA?)

Cancer+: gammarays can damage the circulatory system and heart; anything
related to aging is accelerated by exposure to aging. Cataracts for
instance; astronauts get cataracts; astronauts with zero or low doses,
compared to others;

Human epidemiology studies that showed cancer risks, are showing us
circulatory disease risks: reactor workers, hiroshina survivors, etc.
Russian space agency includes these risks in their cosmonaut dose
limits. Russian Cancer half of the total mortality risk. US fatal risk
from cancer 20%, our dose limits take you from 20% to 23%. Life lose is
the more important factor, non-cancer death have less life lose. If nasa
goes to a system with the other diseases, we have to weight it
something;

Biology of aging, we have to understand common mechanisms, I put a slide
in one of my talks, Einstein's twin paradox, it's reversed; we've funded
some scientists at Tufts in Boston, Jim Joeseph's, tyhey see these
affects exposed to iron particles, aging of the brain, the experiments
are done in high doses;

Radiation Health Officer for stronauts, chielf scientists for space
radiation;

Age and gender are included in our estimates; women are more
suscepticle, breats and overies higher risk; age is latency, some
latency period before the cancer is experessed (10 yer for leukemia, 15
yr for others) if your 60 years you will dies of other causes;

Stroke

MARS ICE 1 meter deep, 1/3 of a meter thickness would give us a nice
reduction; [http://srhp.jsc.nasa.gov](http://srhp.jsc.nasa.gov/)

REPAIR PATHWAYS: single strand breaks, double strand breaks; with
ionizing radiatu=ion you get clustered damaged---all these things next
to Each other; recognition