How much radiation?

After reading some recent reports mentioning ex astronauts now on ground
duties, I wondered if there was some kind of exposure limit for those who
have done long duration flights, at least in the US.

I assume some record of radiation exposure for each is kept??

Brian

--

Brian Gaff....Note, this account does not accept Bcc: email.
graphics are great, but the blind can't hear them
Email:
__________________________________________________ __________________________________________________ __________

In article ,
Brian Gaff wrote:
After reading some recent reports mentioning ex astronauts now on ground
duties, I wondered if there was some kind of exposure limit for those who
have done long duration flights, at least in the US.

Yes, there is. As I understand it, NASA's radiation rules generally
follow the recommendations of NCRP-98, "Guidance on Radiation Received
in Space Activities", 1989, from the National Council on Radiation
Protection and Measurements, although those are now thought to be a
bit too generous for long-term exposures.

Astronauts are legally radiation workers, so monitoring of doses, work
rules that limit them, and efforts to keep them as low as possible, are
legally mandatory.
--
"Think outside the box -- the box isn't our friend." | Henry Spencer
-- George Herbert |

You are touching on a subject that is not pubicized that much. I find
that any scientific research in space medicine that shows detrimental
effects of spaceflight are not talked about too much.

Matthew Ota

Brian Gaff wrote:
After reading some recent reports mentioning ex astronauts now on ground
duties, I wondered if there was some kind of exposure limit for those who
have done long duration flights, at least in the US.

I assume some record of radiation exposure for each is kept??

Brian

Brian Gaff wrote:
After reading some recent reports mentioning ex astronauts now on
ground
duties, I wondered if there was some kind of exposure limit for those
who
have done long duration flights, at least in the US.

I assume some record of radiation exposure for each is kept??

Brian

--

As noted Astronauts are legally radiation workers. I didn't even really
consider this notion till I was reading Baxter's novel, "Voyage" where
a member of the mission to Mars gets grounded and kicked off the flight
because he'd been exposed too much to radiation while conducting
multiple stints aboard a Skylab-type station used in lunar orbit.

I'm noticing that with the exception of Mike Foale none of the
Shuttle-Mir Astronauts (granted, except Foale, only a couple are still
active, Andy Thomas and Dave Wolf) or NASA members of ISS expeditions
have been assigned to follow up ISS expeditions. Not even for crews
down the road yet. This due to some legallity regarding radiation
exposure or does the Astronaut Office just want to give everyone a shot
at a stint aboard ISS?

-A.L.

"Brian Gaff" wrote in message
. uk...
After reading some recent reports mentioning ex astronauts now on ground
duties, I wondered if there was some kind of exposure limit for those who
have done long duration flights, at least in the US.

I assume some record of radiation exposure for each is kept??

Brian

--

Brian Gaff....Note, this account does not accept Bcc: email.
graphics are great, but the blind can't hear them
Email:


I've looked for the same info many years ago. I don't remember the source,
but numbers in the tens of Rads on one Apollo flight. Legal limits have
nothing to do with medical reality, only political.
Anyway, the health risks due to launch and landing far exceed any radiation
health risk.

"bw" wrote in message
...

"Brian Gaff" wrote in message
. uk...
After reading some recent reports mentioning ex astronauts now on ground
duties, I wondered if there was some kind of exposure limit for those who
have done long duration flights, at least in the US.

I assume some record of radiation exposure for each is kept??

Brian

--

Brian Gaff....Note, this account does not accept Bcc: email.
graphics are great, but the blind can't hear them
Email:


I've looked for the same info many years ago. I don't remember the
source, but numbers in the tens of Rads on one Apollo flight. Legal
limits have nothing to do with medical reality, only political.
Anyway, the health risks due to launch and landing far exceed any
radiation health risk.


No, I disagree. You are talking death, I'm talking health issue like Cancer
or problems with sperm or conceiving.

Brian

--

Brian Gaff....Note, this account does not accept Bcc: email.
graphics are great, but the blind can't hear them
Email:
__________________________________________________ __________________________________________________ __________

On 2005-01-20, Brian Gaff wrote:
"bw" wrote in message
...

"Brian Gaff" wrote in message
. uk...
After reading some recent reports mentioning ex astronauts now on ground
duties, I wondered if there was some kind of exposure limit for those who
have done long duration flights, at least in the US.

I assume some record of radiation exposure for each is kept??

Brian

--

Brian Gaff....Note, this account does not accept Bcc: email.
graphics are great, but the blind can't hear them
Email:


I've looked for the same info many years ago. I don't remember the
source, but numbers in the tens of Rads on one Apollo flight. Legal
limits have nothing to do with medical reality, only political.
Anyway, the health risks due to launch and landing far exceed any
radiation health risk.


No, I disagree. You are talking death, I'm talking health issue like Cancer
or problems with sperm or conceiving.

I posted the abstract of a paper studying the effects on eyesight to
sci.space.history the other day... hmm...

Space radiation and cataracts in astronauts
Cucinotta FA, Manuel FK, Jones J, Iszard G, Murrey J, Djojonegro B, Wear M
RADIATION RESEARCH 156 (5): 460-466 Part 1 NOV 2001

"...These results, while preliminary because of the use of subjective
scoring methods, suggest that relatively low doses of space radiation
are causative of an increased incidence and early appearance of
cataracts."

--
-Andrew Gray

In article . com,
Andrew Lotosky wrote:
I'm noticing that with the exception of Mike Foale none of the
Shuttle-Mir Astronauts (granted, except Foale, only a couple are still
active, Andy Thomas and Dave Wolf) or NASA members of ISS expeditions
have been assigned to follow up ISS expeditions. Not even for crews
down the road yet. This due to some legallity regarding radiation
exposure or does the Astronaut Office just want to give everyone a shot
at a stint aboard ISS?

There *are* career limits on exposure, but I suspect this is mostly just
a matter of the overstaffed astronaut corps and a philosophy of giving
everybody a turn.
--
"Think outside the box -- the box isn't our friend." | Henry Spencer
-- George Herbert |

In article , bw wrote:
I've looked for the same info many years ago. I don't remember the source,
but numbers in the tens of Rads on one Apollo flight...

No, the highest exposure on an Apollo lunar expedition was a skin dose of
1.14 rad on Apollo 14. The Skylab 4 crew took 7.74 rads (mean TLD dose)
in their 90-day flight. That's the highest dose on any pre-Challenger
flight (the work for NCRP-98 was done in the post-Challenger hiatus) which
had good monitoring (data for Mercury and Gemini flights is limited).

Legal limits have nothing to do with medical reality, only political.

Legal limits in most places actually track the current state of medical
knowledge of radiation effects reasonably well. There is inevitably a
certain amount of value judgement involved -- there is no such thing as
perfect safety, so one must always decide how much risk is too much --
but political interference has been surprisingly slight.

Anyway, the health risks due to launch and landing far exceed any radiation
health risk.

NCRP-98 specifically recommends astronaut career limits based on a 3% risk
of excess cancer mortality -- roughly comparable to the lifetime risk of
fatal accidents in moderately-dangerous occupations -- with the caveat
that for exploration missions, which have considerable and poorly-known
risks of their own, the limits should be considered guidelines only.
--
"Think outside the box -- the box isn't our friend." | Henry Spencer
-- George Herbert |

"Henry Spencer" wrote in message
...
In article , bw
wrote:
I've looked for the same info many years ago. I don't remember the
source,
but numbers in the tens of Rads on one Apollo flight...

No, the highest exposure on an Apollo lunar expedition was a skin dose of
1.14 rad on Apollo 14. The Skylab 4 crew took 7.74 rads (mean TLD dose)
in their 90-day flight. That's the highest dose on any pre-Challenger
flight (the work for NCRP-98 was done in the post-Challenger hiatus) which
had good monitoring (data for Mercury and Gemini flights is limited).

Ok. The number that was in my head was "14" What I thought remembered was
the listing of all Apollo flights and that just one flight had a higher
exposure than all the others. I'll look up NCRP-98.

Legal limits have nothing to do with medical reality, only political.

Legal limits in most places actually track the current state of medical
knowledge of radiation effects reasonably well. There is inevitably a
certain amount of value judgement involved -- there is no such thing as
perfect safety, so one must always decide how much risk is too much --
but political interference has been surprisingly slight.

Anyway, the health risks due to launch and landing far exceed any
radiation
health risk.

NCRP-98 specifically recommends astronaut career limits based on a 3% risk
of excess cancer mortality -- roughly comparable to the lifetime risk of
fatal accidents in moderately-dangerous occupations -- with the caveat
that for exploration missions, which have considerable and poorly-known
risks of their own, the limits should be considered guidelines only.

Much better answer than mine, thnx. How is "3% risk of excess cancer
mortality" quantified?
I'm sure that statistics are involved and that the "3%" part was decided
politically.

"Think outside the box -- the box isn't our friend." | Henry Spencer
-- George Herbert |