Author Topic: Radiation  (Read 328157 times)

Offline timfinch

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Re: Radiation
« Reply #60 on: March 24, 2018, 03:09:46 PM »
I was a Nuclear electrician aboard a fast attack submarine for 12 years.

Offline Northern Lurker

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Re: Radiation
« Reply #61 on: March 24, 2018, 03:25:58 PM »
I'm not an expert but I'll give my 2 cents.

Having an idea that LEO = radiation safe, cislunar = radiation dangerous and VAB = radiation deadly is wrong. To assess radiation and it's effects you need to know what types of radiation you are encountering, what is each type's flux and energy distribution, duration and repetition of exposure and attenuation of each radiation type.

Van Allen belts traps charged particles and protects everything below it from charged particles. X-rays, gamma rays and neutrons are electrically neutral and are thus immune to VAB. They are attenuated by our atmosphere. That's why you get higher radiation dose while flying because densest part of atmosphere is below you.

Mercury had lowest dose because they were shortest missions with lowest orbits. Outside the protection of atmosphere (x-ray, gamma ray and neutrons) but well below VAB and under it's protection against charged particles.

Gemini had longer missions and higher orbits, thus larger dose. Orbital Apollo missions (7, 9 and ASTP are in this category)

Apollo and shuttle had similar durations (about 2 weeks). Apollo had to traverse Van Allen belts. You can and Apollo did go over radiation belts. Apollo 14 had higher dose because it went through the heart of VAB and had more active radiation environment because of recent solar event. Apollo 14 didn't fry because it crossed the belts with high speed reducing exposure duration. Also capsule made of steel, glass fibre and aluminum attenuated particle radiation from VABs.

Space starts at about 100 km up but atmosphere doesn't end there. It just gets thinner and thinner. Even quite good vacuum creates air resistance when you travel at speeds of few tens of thousands km/h. Because of that, satellites which need to stay in space for long, use higher orbits. Hubble had about 500 km orbit that slices South Atlantic Anomaly on every orbit. Shuttle missions to Hubble had still higher doses because each orbit skirted the SAA until they landed.

Space stations orbit in 400 km so they take hits from SAA too but mission durations are about 6 months to even a year so they have the highest dosages.

Comparing trips to Moon and Mars are incomparable because of different duration. Trip to Moon was about 2 weeks. In 60's they could predict solar activity for a week and used statistics to avoid major solar events during mission. Galactic Gamma Rays are powerful but rare so they don't cause much exposure during 2 week trip. Trip to Mars (one way) is about a year. In mission that long, major solar events are certain and doses from GGRs add up. That's why we could do 2 week Moon mission but 2+ years long mission to Mars needs improved radiation protection.

Lurky


« Last Edit: March 24, 2018, 03:31:08 PM by Northern Lurker »

Offline Northern Lurker

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Re: Radiation
« Reply #62 on: March 24, 2018, 03:32:27 PM »
I was a Nuclear electrician aboard a fast attack submarine for 12 years.

I'm not familiar with navy, so how much education and experience about radiation that means?

Offline timfinch

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Re: Radiation
« Reply #63 on: March 24, 2018, 03:49:04 PM »
I'm not an expert but I'll give my 2 cents.

Having an idea that LEO = radiation safe, cislunar = radiation dangerous and VAB = radiation deadly is wrong. To assess radiation and it's effects you need to know what types of radiation you are encountering, what is each type's flux and energy distribution, duration and repetition of exposure and attenuation of each radiation type.

Van Allen belts traps charged particles and protects everything below it from charged particles. X-rays, gamma rays and neutrons are electrically neutral and are thus immune to VAB. They are attenuated by our atmosphere. That's why you get higher radiation dose while flying because densest part of atmosphere is below you.

Mercury had lowest dose because they were shortest missions with lowest orbits. Outside the protection of atmosphere (x-ray, gamma ray and neutrons) but well below VAB and under it's protection against charged particles.

Gemini had longer missions and higher orbits, thus larger dose. Orbital Apollo missions (7, 9 and ASTP are in this category)

Apollo and shuttle had similar durations (about 2 weeks). Apollo had to traverse Van Allen belts. You can and Apollo did go over radiation belts. Apollo 14 had higher dose because it went through the heart of VAB and had more active radiation environment because of recent solar event. Apollo 14 didn't fry because it crossed the belts with high speed reducing exposure duration. Also capsule made of steel, glass fibre and aluminum attenuated particle radiation from VABs.

Space starts at about 100 km up but atmosphere doesn't end there. It just gets thinner and thinner. Even quite good vacuum creates air resistance when you travel at speeds of few tens of thousands km/h. Because of that, satellites which need to stay in space for long, use higher orbits. Hubble had about 500 km orbit that slices South Atlantic Anomaly on every orbit. Shuttle missions to Hubble had still higher doses because each orbit skirted the SAA until they landed.

Space stations orbit in 400 km so they take hits from SAA too but mission durations are about 6 months to even a year so they have the highest dosages.

Comparing trips to Moon and Mars are incomparable because of different duration. Trip to Moon was about 2 weeks. In 60's they could predict solar activity for a week and used statistics to avoid major solar events during mission. Galactic Gamma Rays are powerful but rare so they don't cause much exposure during 2 week trip. Trip to Mars (one way) is about a year. In mission that long, major solar events are certain and doses from GGRs add up. That's why we could do 2 week Moon mission but 2+ years long mission to Mars needs improved radiation protection.

Lurky
The daily rate can be compared if not the mission dose.  Look at the data from the Orion test that traveled 3600 miles into the VAB and compare the results of that test to the radiation dose of say Apollo 17 that supposedly traveled through the heart of the VAB.

Offline timfinch

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Re: Radiation
« Reply #64 on: March 24, 2018, 03:53:34 PM »
Submarine Nuclear Operators are given college level training in Thermodynamics, Metallurgy, Chemistry, Nuclear Plant construction and Radiology.  Our training is administered, regulated and tested by the Nuclear Atomic commision. 

Offline BertieSlack

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Re: Radiation
« Reply #65 on: March 24, 2018, 05:21:20 PM »
I have examined everything I could find on the subject.  I have combed the NASA sites and looked at most of the conspiracy sites.  I looked at the Chang'e and Selene data and the Zond data.  I have a background in radiation work and it struck me as odd that the Lunar mission doses were so similar to the LEO doses that I pursued the data trying to come to terms with why that was the case.  Everything I have researched indicates one of two things.  Either the data is incorrect/fabricated or it was taken from LEO missions and not actual lunar transits.

You're claiming that the Soviets fabricated the Zond data in 1968? You know the Zond missions photographed the Moon, right? Are those photos fake too?
You're claiming that Chandrayaan-1 data is faked too? You know the Chandrayaan mission photographed the Moon, right? Are those photos fake too?

Offline timfinch

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Re: Radiation
« Reply #66 on: March 24, 2018, 05:52:24 PM »
The only claim I make is the radiation exposure of the Apollo lunar missions do not coincide with expected values using empirical data from the 21st century.  That is the extent of my claim.

Offline bknight

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Re: Radiation
« Reply #67 on: March 24, 2018, 06:07:46 PM »
I'm not an expert but I'll give my 2 cents.

Having an idea that LEO = radiation safe, cislunar = radiation dangerous and VAB = radiation deadly is wrong. To assess radiation and it's effects you need to know what types of radiation you are encountering, what is each type's flux and energy distribution, duration and repetition of exposure and attenuation of each radiation type.

Van Allen belts traps charged particles and protects everything below it from charged particles. X-rays, gamma rays and neutrons are electrically neutral and are thus immune to VAB. They are attenuated by our atmosphere. That's why you get higher radiation dose while flying because densest part of atmosphere is below you.

Mercury had lowest dose because they were shortest missions with lowest orbits. Outside the protection of atmosphere (x-ray, gamma ray and neutrons) but well below VAB and under it's protection against charged particles.

Gemini had longer missions and higher orbits, thus larger dose. Orbital Apollo missions (7, 9 and ASTP are in this category)

Apollo and shuttle had similar durations (about 2 weeks). Apollo had to traverse Van Allen belts. You can and Apollo did go over radiation belts. Apollo 14 had higher dose because it went through the heart of VAB and had more active radiation environment because of recent solar event. Apollo 14 didn't fry because it crossed the belts with high speed reducing exposure duration. Also capsule made of steel, glass fibre and aluminum attenuated particle radiation from VABs.

Space starts at about 100 km up but atmosphere doesn't end there. It just gets thinner and thinner. Even quite good vacuum creates air resistance when you travel at speeds of few tens of thousands km/h. Because of that, satellites which need to stay in space for long, use higher orbits. Hubble had about 500 km orbit that slices South Atlantic Anomaly on every orbit. Shuttle missions to Hubble had still higher doses because each orbit skirted the SAA until they landed.

Space stations orbit in 400 km so they take hits from SAA too but mission durations are about 6 months to even a year so they have the highest dosages.

Comparing trips to Moon and Mars are incomparable because of different duration. Trip to Moon was about 2 weeks. In 60's they could predict solar activity for a week and used statistics to avoid major solar events during mission. Galactic Gamma Rays are powerful but rare so they don't cause much exposure during 2 week trip. Trip to Mars (one way) is about a year. In mission that long, major solar events are certain and doses from GGRs add up. That's why we could do 2 week Moon mission but 2+ years long mission to Mars needs improved radiation protection.

Lurky
The daily rate can be compared if not the mission dose.  Look at the data from the Orion test that traveled 3600 miles into the VAB and compare the results of that test to the radiation dose of say Apollo 17 that supposedly traveled through the heart of the VAB.

The trajectories of Orion and any Apollo Lunar mission is significantly different.  Orion did indeed go through the most dangerous portion of the VARB, where all the Apollo Lunar mission had outbound and inbound trajectories through the least dangerous portions of the VARB.  Therefore you are in error comparing those events
Truth needs no defense.  Nobody can take those footsteps I made on the surface of the moon away from me.
Eugene Cernan

Offline bknight

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Re: Radiation
« Reply #68 on: March 24, 2018, 06:19:22 PM »
The only claim I make is the radiation exposure of the Apollo lunar missions do not coincide with expected values using empirical data from the 21st century.  That is the extent of my claim.

You do realize that the data of the Mars mission was determined with little radiation protection whereas the Apollo capsule were layered with low density material and stainless steel.  Both are good insulators to radiation so the rates should be lower than those derived by Curiosity mission.
Truth needs no defense.  Nobody can take those footsteps I made on the surface of the moon away from me.
Eugene Cernan

Offline timfinch

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Re: Radiation
« Reply #69 on: March 24, 2018, 06:36:18 PM »
The only claim I make is the radiation exposure of the Apollo lunar missions do not coincide with expected values using empirical data from the 21st century.  That is the extent of my claim.

You do realize that the data of the Mars mission was determined with little radiation protection whereas the Apollo capsule were layered with low density material and stainless steel.  Both are good insulators to radiation so the rates should be lower than those derived by Curiosity mission.

In a word, No.  You should recheck your notes on this as I believe you are completely wrong.

Offline Ranb

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Re: Radiation
« Reply #70 on: March 24, 2018, 06:38:23 PM »
Submarine Nuclear Operators are given college level training in Thermodynamics, Metallurgy, Chemistry, Nuclear Plant construction and Radiology.  Our training is administered, regulated and tested by the Nuclear Atomic commision. 
I was an ELT on several nuke boats and completed article 108 training for a billet at a shore facility.  My training in radiological controls far exceeds yours as an electrician on a submarine.  I would not call what we got at nuke school, "college level" anything as our course work was based on algebra.  Only the officers got calculus based training unless the course was updated recently.

Ranb

Offline timfinch

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Re: Radiation
« Reply #71 on: March 24, 2018, 06:39:48 PM »
I'm not an expert but I'll give my 2 cents.

Having an idea that LEO = radiation safe, cislunar = radiation dangerous and VAB = radiation deadly is wrong. To assess radiation and it's effects you need to know what types of radiation you are encountering, what is each type's flux and energy distribution, duration and repetition of exposure and attenuation of each radiation type.

Van Allen belts traps charged particles and protects everything below it from charged particles. X-rays, gamma rays and neutrons are electrically neutral and are thus immune to VAB. They are attenuated by our atmosphere. That's why you get higher radiation dose while flying because densest part of atmosphere is below you.

Mercury had lowest dose because they were shortest missions with lowest orbits. Outside the protection of atmosphere (x-ray, gamma ray and neutrons) but well below VAB and under it's protection against charged particles.

Gemini had longer missions and higher orbits, thus larger dose. Orbital Apollo missions (7, 9 and ASTP are in this category)

Apollo and shuttle had similar durations (about 2 weeks). Apollo had to traverse Van Allen belts. You can and Apollo did go over radiation belts. Apollo 14 had higher dose because it went through the heart of VAB and had more active radiation environment because of recent solar event. Apollo 14 didn't fry because it crossed the belts with high speed reducing exposure duration. Also capsule made of steel, glass fibre and aluminum attenuated particle radiation from VABs.

Space starts at about 100 km up but atmosphere doesn't end there. It just gets thinner and thinner. Even quite good vacuum creates air resistance when you travel at speeds of few tens of thousands km/h. Because of that, satellites which need to stay in space for long, use higher orbits. Hubble had about 500 km orbit that slices South Atlantic Anomaly on every orbit. Shuttle missions to Hubble had still higher doses because each orbit skirted the SAA until they landed.

Space stations orbit in 400 km so they take hits from SAA too but mission durations are about 6 months to even a year so they have the highest dosages.

Comparing trips to Moon and Mars are incomparable because of different duration. Trip to Moon was about 2 weeks. In 60's they could predict solar activity for a week and used statistics to avoid major solar events during mission. Galactic Gamma Rays are powerful but rare so they don't cause much exposure during 2 week trip. Trip to Mars (one way) is about a year. In mission that long, major solar events are certain and doses from GGRs add up. That's why we could do 2 week Moon mission but 2+ years long mission to Mars needs improved radiation protection.

Lurky
The daily rate can be compared if not the mission dose.  Look at the data from the Orion test that traveled 3600 miles into the VAB and compare the results of that test to the radiation dose of say Apollo 17 that supposedly traveled through the heart of the VAB.

The trajectories of Orion and any Apollo Lunar mission is significantly different.  Orion did indeed go through the most dangerous portion of the VARB, where all the Apollo Lunar mission had outbound and inbound trajectories through the least dangerous portions of the VARB.  Therefore you are in error comparing those events

I guess you should review the trajectories of all the Apollo missions.  I am told that Apollo 17 went through the heart of the VAB.  It would be great if there was an overlay showing all of the missions paths through the VAB.  I have only found the one for Apollo 11 and I doubt the veracity of it.

Offline Ranb

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Re: Radiation
« Reply #72 on: March 24, 2018, 06:40:29 PM »
Look at the data from the Orion test that traveled 3600 miles into the VAB and compare the results of that test to the radiation dose of say Apollo 17 that supposedly traveled through the heart of the VAB.
Bolding mine.  Evidence to support this claim?

I am told that Apollo 17 went through the heart of the VAB.  It would be great if there was an overlay showing all of the missions paths through the VAB.  I have only found the one for Apollo 11 and I doubt the veracity of it.
Who told you this?

Offline timfinch

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Re: Radiation
« Reply #73 on: March 24, 2018, 06:44:24 PM »
Submarine Nuclear Operators are given college level training in Thermodynamics, Metallurgy, Chemistry, Nuclear Plant construction and Radiology.  Our training is administered, regulated and tested by the Nuclear Atomic commision. 
I was an ELT on several nuke boats and completed article 108 training for a billet at a shore facility.  My training in radiological controls far exceeds yours as an electrician on a submarine.  I would not call what we got at nuke school, "college level" anything as our course work was based on algebra.  Only the officers got calculus based training unless the course was updated recently.

Ranb

I was a Navy Nuke from 1979 to 1991.  Unless you attended Nuke School in the late seventies or early eighties then you have no idea what we were taught.  Maybe you should ask someone.

Offline timfinch

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Re: Radiation
« Reply #74 on: March 24, 2018, 06:53:22 PM »
Look at the data from the Orion test that traveled 3600 miles into the VAB and compare the results of that test to the radiation dose of say Apollo 17 that supposedly traveled through the heart of the VAB.
Bolding mine.  Evidence to support this claim?

I am told that Apollo 17 went through the heart of the VAB.  It would be great if there was an overlay showing all of the missions paths through the VAB.  I have only found the one for Apollo 11 and I doubt the veracity of it.
Who told you this?

I actually read it in one of the threads here.  I have searched for corroboration but as yet I have been unable to confirm it.