Dose during Mars trip -Reply

[FRAMEP@ORAU.GOV]

Rick Strickert wrote:

>Does anyone happen to know the approximate dose an astronaut might
>receive during a RT to Mars without extra shielding?   What increase in
>dose might be expected from a solar flare during the trip?

Rick:

It was suggested that the answer might be found on a NASA web site. I
haven't checked it out so I don't know how the following numbers match
up.  A Mars Mission might be 2-3 years.

Annual Galactic Cosmic Radiation:
53 cSv skin and 39 cSv blood forming organs at 5 cm depth

Huge Solar Flare like that in 1972
172 cSv skin and 49 cSv bloodforming organs at 5 cm depth

These numbers are from "Radiation Protection Effectiveness of a
Proposed Magnetic Shielding Concept for Manned Mars Missions"
Townsend et al, SAE Technical Paper 901343, 1990. They assumed no
shielding.  They concluded that  a bulk water shield was most effective.
With a 22 g/sq cm water shield the annual galactic cosmic ray dose
would be  27 cSv to the skin 24 cSv to the blood forming organs. With
the same shield the 1972 solar flare would have produced 9 cSv to the
skin and 5 cSv to the blood forming organs.

Gotta run. Quitting time was an hour ago :-(

Paul Frame
Professional Training Programs
ORISE
framep@orau.gov