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Professor L Speaks Out On The Space Radiation Issue May 27, 2006

Posted by drspaceshow in Uncategorized.
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I’ve been following the discussion on this site and others regarding two recent articles on space radiation. The first article appeared in the March 2006 edition of Scientific American. This article was written by Eugene N. Parker. The second article appeared in the June 2006 issue of Discover Magazine and was written by M.G. Lord. This article is titled “Are We Trapped On Earth? Impossible Journey.”

While I have my own thoughts on what is valid about the issue of cosmic radiation and its effect on long term space flight participants, I won’t share them with you at this time. Instead, I want to urge those interested in this discussion to do your own checking of the sources and make up your own mind as to which side of the discussion you believe to be more valid or completely valid. Since I have in front of me the two articles referenced above, I can easily list the sources from both articles and the URLs where readers can find out more about the radiation issue directly from the sources used for the articles.

Clark, because I do not have any sources handy for the information you cite, can you please post a comment to this message and list some sources and URLs for interested readers to find out more about what your are talking about and suggesting? Even a mini-literature search would suffice.

Again, those of you interested in this subject, check out the sources used by the writers of the articles and by Clark. Then make up your own mind as to the validity of the arguments on either side of the issue regarding cosmic rays and humans in space. Remember, a key component in critical thinking and discernment is that you compel yourself to step outside your own point view, your own prejudice and your own agenda. You want to be as unbiased as possible and open minded as possible so your critical thinking and discernment skills can kick in.

If you do check out the source material on this topic, which by the way is an important topic and this is an important discussion, please post your thought, analysis, and conclusions here on Space-Cynic.

Thanks. Happy researching to each of you.

Sources: These sources are not meant to be the final word on this subject. They are simply starters for your research and were cited by the magazine articles. Obviously to do proper research and due diligence, your own source investigation should include additional sources on both sides of the issue. But this is a good list for starters.

Scientific America:
Eugene N. Parker: http://www.phys-astro.sonoma.edu/BruceMedalists/Parker/ParkerRefs.html

http://www.agu.org/inside/awards/parker.html

Office of Aerospace Medicine Civil Aerospace Medical Institute, FAA: http://www.faa.gov/about/office_org/headquarters_offices/avs/offices/aam/cami/

Dr. Wallace Friedberg:: http://www.mmac.faa.gov/intercom/010511.htm
Into fencing? Meet ‘The Wall.’Radiation biologist thrust of awardBy Mike WaydaWhile he may appear mild-mannered to his colleagues at the Civil Aeromedical Institute, Dr. Wallace Friedberg, FAA radiation biologist, is known as “The Wall” to his fencing competitors. ‘The Wall’: CAMI’s Dr. Friedberg in fencing gear.Friedberg, a long-time devotee of the sport of fencing, was recently honored by the Redlands Fencing Club with a lifetime achievement award for his 30-plus years of participating in and promoting the sport.

Before participating in an Oklahoma-wide tournament on March 24, Friedberg was presented with the award, which came as a “big surprise” to him. When asked what one would need to do to win a lifetime achievement trophy, he said, “You have to be able to survive and to persevere.”

In one of his very early matches, Friedberg was somehow wounded and needed a few stitches in his hand. He survived that, as well as other challenges in his life, including a bout with cancer, and he has persevered in his pursuit of excellence in the sport — and at work.
In 1960, Friedberg joined the staff of the Civil Aeromedical Research Institute, as it was known then. He was among a group of researchers and scientists who were hired first to work at the FAA institute. He and two other CAMI employees are now the only ones of the original “dinosaurs,” as they referred to themselves, still working after 41 years.
Friedberg says he takes fencing “very seriously,” practicing and taking lessons on a regular basis. He is expert in the épée, a time-honored weapon wielded in fencing competitions, and he has won the state championship several times.
As a competitor, the 73-year-old Friedberg is acknowledged as being anything other than mild-mannered. ###(Wayda is editor of The Federal Air Surgeon’s Medical Bulletin, his report appears in the Spring, 2001 ed.)

Space Radiation Shielding Program at Marshall Space Flight Center:
http://www.nasa.gov/centers/marshall/news/news/releases/2003/03-183.html
http://server.c-ad.bnl.gov/esfd/nsrl/index.html

Radiation Shielding for Human Interplanetary Exploration and Discovery, a NASA sponsored workshop for the Univ. of Michigan: http://aoss.engin.umich.edu/Radiation/

Samuel C.C. Ting, MIT: http://nobelprize.org/physics/laureates/1976/ting-autobio.html

National Space Radiation Lab at Brookhaven National Laboratory:
http://www.bnl.gov/medical/NASA/NSRL_description.asp

Discover Magazine:
Francis Cucinotta, Chief Scientist at NASA’s radiation program:
http://www.islandone.org/ISDC/ISDC1999_Houston/ISDC99-Abstracts_CD/NSS%20Bios/Francis%20Cucinotta.pdf

Jacob Bloomberg, Neuroscientist at Johnson Space Center
http://www.nasa.gov/pdf/64087main_ffs_bio_bloomberg.pdf

Dr. Marcelo Vazquez, Brookhaven National Labs
http://www.bnl.gov/medical/Personnel/Vazquez/default.htm

Duane Pierson, NASA Microbiologist:
http://www.isso.uh.edu/postdoc/2004/fox.htm scroll to the bottom of this page for a brief biography of Dr. Pierson. His papers on radiation topics can be found on the web using Google.

John Charles, NASA Space Life Sciences Division:
http://spaceflight.nasa.gov/history/shuttle-mir/people/to-p-t-charles.htm

Shannon Lucid: http://www.jsc.nasa.gov/Bios/htmlbios/lucid.html

Mike Fincke: http://www.jsc.nasa.gov/Bios/htmlbios/fincke.html

Dr. Lakshmi Putcha: lputcha@ems.jsc.nasa.gov Pharmacotherapeturics researcher at Life Sciences Lab at Johnson.

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Comments»

1. Clark - May 27, 2006

Hi David,
Thanks for the reference list. With regard to my objections to the SciAm article, it’s not as if I’m claiming that any of the particular facts given there are wrong. I’m perfectly happy to accept, for example, that 5m of water will reduce GCR backgronds to that found on a high mountain on earth. I’m perfectly aware that the health danger of GCR exposures above such levels is an extremely complex and controversal issue. What I’ve objected to is the extreme conclusion drawn from those facts that GCR may present an “insurmountable” barrier to humans living in space. It clearly does not.

This is not a fundamental physics or biology issue, it’s a technology question. There is nothing inherently unstoppable about radiation out there. Unfortunately, I think a lot of readers come away from such articles convinced that there is.

An assumption behind the the article is that delivering large quantities of water, or the equivalent mass of denser materials, to space is simply beyond the pale. But it is not. For near earth habitats (e.g. LEO, L1, etc), it is clearly within our technological grasp to put enough material into orbit to provide radiation protection to whatever level is desired. For early pioneers this level will be allowed to be fairly high. For later “regular folk” types, it can be set much lower, even to earth surface levels.

One way to do this would be to combine the orbiting supply depot concept with space habitats. That is, surround a habitat like that of Bigelow’s with the tanks of water, fuel, and other materials that are meant to supply the in-space infrastructure.

The proposal of fuel/water/bulk supplies depot in orbit is an idea that has been around for awhile but is just now starting to become accepted in mainstream aerospace. E.g. Griffin recently endorsed the concept: Griffin wants orbiting fuel depot: NASA chief asks private businesses for assistance – Florida Today – Dec.7.06

Similarly, proposals to supply such materials to LEO with cheap dumb boosters (i.e. when you lose one it’s no big deal) has also been around for years. One scheme is the Aquarius SSTO concept developed by Space Systems/Loral. I mentioned it before but I don’t mean to imply that the Aquarius project is the ultimate in mass cargo delivery systems to orbit. I’m just using it as a proof of principle that such a system has been studied in detail by a reputable group and found by them to be feasible. Some other dumb booster scheme might very well be found superior if a competition were held. Anyway, here is a presentation about the Aquarius system given at ISDC (basically the same as given at Space Access’06): Aquarius: Enabler of Big and Small Space Projects – Andrew Turner of SS/Loral at ISDC06

Note that one does not need to surround a habitat literally with 5 meters of water. Water could be used in combination with layers of denser materials to provide a much thinner shield. Other available materials without water could be used as well. I’ve always thought that dumping Mir was a huge waste simply because all that mass put into orbit at great expense could have been saved to shield a future habitat. If nothing else, the ISS may be useful someday by being chopped up to shield a Bigelow space hotel… 😉

In regards to electrostatic and magnetic shielding, I gave a couple of references to NASA study papers in an earlier comment. On the short term they aren’t needed but it would be nice if one or both approaches eventually become practical. One thing that really annoyed me about the SciAm article is that the examples it gave for electrostatic and magnetic shielding each required that such a system provide all of the shielding all by itself. That’s just silly. Such a system would, of course, be used as a supplement to material shielding, not to replace it entirely. Furthermore, it’s quite possible that perhaps only one section of a spacecraft, e.g. a large viewing portal, would be protected by, say, an electrostatic grid.

With regard to Mars missions, I mentioned the cycler concept and the fact that the shielding for it could be built up to a high level. Here is a long list of references for cyclers. (Note, a student recently won a NASA grant to study the use of natural cyclers for Mars trips.

Finally, here are a bunch of links I’ve accumulated about space radiation and about radiation shielding.

– Clark

2. Professor L - May 28, 2006

Clark, thanks for the references. This should help people brush up on the facts and the arguments and learn about this issue and the issues related to it. I appreciate your taking the time to provide some good source material different from what appeared in the two magazine articles.

3. Paul Dietz - May 28, 2006

Yes, all those paragraphs about fencing will be a wonderful input for deciding about radiation effects.

(rolls eyes)

4. Professor L - May 28, 2006

Paul, help me out with a clarification. I am missing something re fencing per your comments. I don’t believe any of the magazine article sources I listed pertain to fencing unless I have not read or researched deeply enough. I have not had time to check out Clark’s links. So I would appreciate your explaining the fencing comments. Thanks and thank you for posting.

5. TomsRants - May 29, 2006

David, apparently some of your copying and pasting picked up some stuff about fencing. There are a lot of unrelated articles on the linked page. Just a lesson in discernment in editing before posting…you know, like paragraph breaks.

6. Professor L - May 29, 2006

Tom, it was written in Word, all links tested and uploaded posted to space-cynic. On my system, it appeared correct, hence, my note to Paul for clarification. I know you will blame it on my using a PC instead of a Mac but there was very careful editing in Word and then checking it befor I hit the post button. I have no clue how it brought in other material. Furthermore, I just checked my original Word file and its correct with all the links. Explanations are welcome, if you insist is a PC versus Mac thing. You might as well be upfront about your prejudice.

7. Professor L - May 29, 2006

One additional thing. For Dr. Wallace Friedberg, it was very hard to find an online bio for him. The article I posted had more bio info on him than other articles, including his activity in fencing. Maybe he needs to sword fight his way to victory for his ideas and research. What do you think?

In any event, one can focus on what they want. People can do their own due diligence and research on the subject of space radiation and its impact on humans for long term space flight and staying in space for long periods of time, or one can take others and their agenda/ideas as the gospel, one can accept scientific facts, do what they want with the information, or, do nothing.

In any event, Dr. Friedberg and his fencing is not relevant to the discussion about cosmic radiation and humans in space but his work was cited in the Scientific American article, thus his bio is there for people to see (as much of a bio as I could find). I encourage discernment in the use of the information provided in all the links provided, including the information posted about Dr. Friedberg.

8. TomsRants - May 29, 2006

Sorry to disappoint you, David, but I wasn’t even going there with the platform thing. More often than not it’s an issue of programming within the web page itself. I was at a site the other day that just insisted I needed Flash 6 to view their content, and “please click here to upgrade your Flash plug-in”. I’m using Flash 8. Their scripting didn’t allow for version numbers greater than 6. Clearly they hadn’t updated in awhile. The greater the demand for web content, the greater the risk for sloppy output.

9. Paul Dietz - May 29, 2006

it was written in Word

Well, slap yourself silly and don’t do that again. Word is not an editor, it’s an overcomplicated word processor.

10. Kelly Starks - June 2, 2006

As to the radiation topic.

I can see where radiation demands you include shielding on deep space ships and stations. Which is a cost and design issue – but not a brick wall.

EVA and suited surface ops on Luna and Mars would be a bigger risk, but you wouldn’t spend that much time outside like that.

11. Michael Turner - August 2, 2006

There seems to be an impression that denser shield materials are better. What I keep reading, though, is that the secondary radiation effects are the problem, when it comes to GCR. If you had a choice between a liquid hydrogen shield and a lead shield of the same density per unit area, you’d want hydrogen. (Water is favored in part because it has a high hydrogen composition; similarly for certain plastics).

Why the difference?

A GCR particle smacking into the lead would cause lead particles (their nuclei, or fragments of their nuclei?) to spray out the other side–and into you. A GCR particle smacking into liquid hydrogen would cause hydrogen atoms (or protons, anyway) to spray out the other side into you. Either form of secondary radiation will have a significant fraction of the kinetic energy of the GCR particle. So which kind of “secondary radiation” you rather have coming at you at 50 mph: 50 lbs of bowling balls (or fragments thereof) or 50 lbs of birdshot? Gimme the birdshot any day.

Tell me my mental model of this problem is all wrong ….


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