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Old 06-13-2018, 08:20 PM
 
Location: Ohio
20,681 posts, read 14,654,220 times
Reputation: 16938

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Quote:
Originally Posted by Tantalust View Post
I've wondered about health statistics of people on higher elevations, as opposed to sea-level. Is there any evidence of increased radiation risks when living up there?
Yes. People who live in Denver, Colorado and in Mexico City, Mexico receive higher doses.

People who live in the Rocky Mountains and in southern India receive additional higher doses due to their close proximity to radionuclides in the earth or in the case of southern India, the soil and beaches are full of thorium silt.

Flying increases your dosage, too.

Quote:
Originally Posted by ocpaul20 View Post
I was not aware that any of the Mars rovers returned home to Earth, did they?
It transmitted collected data on radiation from sensors to Earth.

Quote:
Originally Posted by ocpaul20 View Post
Assuming people do not know or cannot be bothered to look it up is dangerous to your argument.

This The Guardian UK newspaper article suggests that a dose of 1Sv is not fatal but would cause radiation sickness. Measurements in Sv/1000 or mSv (1Sv = 1000mSv)
The Guardian article is just plain wrong.

The dose of radiation expected to cause death to 50 percent of an exposed population within 30 days (Lethal Dose 50%-30 Days is LD 50/30 for short). Typically, the LD 50/30 is in the range from 400 to 450 rem (4 to 5 sieverts) received over a very short period. A "short period" is several hours up to perhaps 1-3 days at the most.

1 Sv over a period of 6 months is not going to cause radiation sickness.

Humans and mammals, as well as other life-forms, can tolerate low doses of radiation over extended periods of time.

Contrary to popular belief, spacecraft are shielded to some extent. The glass for the windows on the command module contains gold dust particles, which reflect radiation back into space. The metals used in construction of the command module itself are also specially treated to reflect radiation.

 
Old 06-13-2018, 08:57 PM
 
33,709 posts, read 17,275,623 times
Reputation: 18491
Quote:
Originally Posted by Mircea View Post
Contrary to popular belief, spacecraft are shielded to some extent. The glass for the windows on the command module contains gold dust particles, which reflect radiation back into space. The metals used in construction of the command module itself are also specially treated to reflect radiation.
The thermal insulation as well. Common polyethylene has a lot of nice hydrogen atoms, just the thing for particle radiation.
 
Old 06-17-2018, 02:52 PM
 
7,129 posts, read 3,895,051 times
Reputation: 6675
Quote:
Originally Posted by Mircea View Post

1 Sv over a period of 6 months is not going to cause radiation sickness.

Humans and mammals, as well as other life-forms, can tolerate low doses of radiation over extended periods of time.
Exactly. Excessive sunlight over a few hours gives a sunburn. The equivalent over a month just provides Vitamin D

Every spacecraft design I’ve seen employs a layered approach of passive and active radiation shielding.
 
Old 06-18-2018, 01:42 PM
 
Location: Houston, Texas
1,178 posts, read 1,354,139 times
Reputation: 389
Quote:
Originally Posted by Mircea View Post
Yes. People who live in Denver, Colorado and in Mexico City, Mexico receive higher doses.

People who live in the Rocky Mountains and in southern India receive additional higher doses due to their close proximity to radionuclides in the earth or in the case of southern India, the soil and beaches are full of thorium silt.

Flying increases your dosage, too.



It transmitted collected data on radiation from sensors to Earth.



The Guardian article is just plain wrong.

The dose of radiation expected to cause death to 50 percent of an exposed population within 30 days (Lethal Dose 50%-30 Days is LD 50/30 for short). Typically, the LD 50/30 is in the range from 400 to 450 rem (4 to 5 sieverts) received over a very short period. A "short period" is several hours up to perhaps 1-3 days at the most.

1 Sv over a period of 6 months is not going to cause radiation sickness.

Humans and mammals, as well as other life-forms, can tolerate low doses of radiation over extended periods of time.

Contrary to popular belief, spacecraft are shielded to some extent. The glass for the windows on the command module contains gold dust particles, which reflect radiation back into space. The metals used in construction of the command module itself are also specially treated to reflect radiation.
They also use lead to block some radiation if I recall. Although, isn’t it also true that the space station is still under protection from Earth’s magnetic field?

Which is why NASA is currently working on materials that wouldn’t add too much mass to the spacecraft (since more mass requires more fuel) to protect against radiation for a trip to Mars.
 
Old 06-22-2018, 04:46 PM
 
Location: Mars City
5,536 posts, read 2,404,229 times
Reputation: 8161
Quote:
Originally Posted by Canaan-84 View Post
...isn’t it also true that the space station is still under protection from Earth’s magnetic field?
The Earth's magnetic field is not an issue for the space station. No danger there.

The space station must protect the inhabitants from the sun's intense radiation, as well as meteorite hits. It must also maintain "atmospheric" pressure, a habitable temperature range, remove exhaled carbon dioxide, and provide breathable oxygen content.

Last edited by Thoreau424; 06-22-2018 at 05:34 PM..
 
Old 06-25-2018, 03:16 AM
 
Location: Houston, Texas
1,178 posts, read 1,354,139 times
Reputation: 389
Quote:
Originally Posted by Thoreau424 View Post
The Earth's magnetic field is not an issue for the space station. No danger there.

The space station must protect the inhabitants from the sun's intense radiation, as well as meteorite hits. It must also maintain "atmospheric" pressure, a habitable temperature range, remove exhaled carbon dioxide, and provide breathable oxygen content.
I didn’t say it was a danger, I said the space station crew is protected from solar radiation thanks to it being within the Earth’s magnetic field.
 
Old 06-25-2018, 10:38 AM
 
Location: Mars City
5,536 posts, read 2,404,229 times
Reputation: 8161
Quote:
Originally Posted by Canaan-84 View Post
... the space station crew is protected from solar radiation thanks to it being within the Earth’s magnetic field.
That's not true. The Earth's magnetic field doesn't not protect against radiation.

We aren't even fully protected on the ground from solar radiation (think of sunburn, for example). And outside of the filtering and protection of layers of the atmosphere - with help from ozone too - it is significantly more hazardous. There is INTENSE radiation from the sun outside of our atmosphere. And there's little difference whether on orbit around Earth (like with the space station), on the Moon, or other areas. The space station, space-walking astronauts, Shuttle, Apollo, and those who walked the Moon all had to be heavily protected from radiation.

Do some research, instead of guessing and assuming.
 
Old 06-25-2018, 10:44 AM
 
Location: Houston, Texas
1,178 posts, read 1,354,139 times
Reputation: 389
Quote:
Originally Posted by Thoreau424 View Post
That's not true. The Earth's magnetic field doesn't not protect against radiation.

We aren't even fully protected on the ground from solar radiation (think of sunburn, for example). And outside of the filtering and protection of layers of the atmosphere - with help from ozone too - it is significantly more hazardous. There is INTENSE radiation from the sun outside of our atmosphere. And there's little difference whether on orbit around Earth (like with the space station), on the Moon, or other areas. The space station, space-walking astronauts, Shuttle, Apollo, and those who walked the Moon all had to be heavily protected from radiation.

Do some research, instead of guessing and assuming.
From NASA:https://www.nasa.gov/feature/goddard...iation-on-mars

“Fortunately for us, Earth’s natural protections block all but the most energetic of these particles from reaching the surface. A huge magnetic bubble, called the magnetosphere, which deflects the vast majority of these particles, protects our planet. And our atmosphere subsequently absorbs the majority of particles that do make it through this bubble. Importantly, since the International Space Station (ISS) is in low-Earth orbit within the magnetosphere, it also provides a large measure of protection for our astronauts.”
 
Old 06-25-2018, 12:20 PM
 
Location: Mars City
5,536 posts, read 2,404,229 times
Reputation: 8161
Though that obviously comes from a NASA site, it's still incorrect, crazy as that sounds. I can see where people would believe that - since it looks official - but I've worked in that field, and know the above statement to be untrue.

The science behind NASA and it's employees has taken a huge hit over the years. Modern "NASA" and the organization that put us on the moon are two vastly different worlds. I've witnessed that repeatedly, and this is unfortunately another example. Very sad...
 
Old 06-25-2018, 12:40 PM
 
33,709 posts, read 17,275,623 times
Reputation: 18491
Quote:
Originally Posted by Thoreau424 View Post
That's not true. The Earth's magnetic field doesn't not protect against radiation.
That is completely incorrect. The Van Allen belts only exist due to Earth's magnetic field, and they are a major factor in reducing solar radiation.

https://en.wikipedia.org/wiki/Van_Allen_radiation_belt

Quote:
We aren't even fully protected on the ground from solar radiation (think of sunburn, for example).
Not fully, no. But without Earth's magnetic field, we'd be subject to considerably heavier radiation.

Quote:
And there's little difference whether on orbit around Earth (like with the space station), on the Moon, or other areas.
Incorrect. Solar particle radiation goes wildly up once you venture beyond the Van Allen belts. Astronauts on the ISS can shrug off sunspot activity thanks to the protection offered by the belts. That is very much not the case once you leave LEO.

Quote:
Do some research, instead of guessing and assuming.
Good advice.
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