jump to navigation

Gerald Driggers, Monday, 9-21-15 September 22, 2015

Posted by The Space Show in Uncategorized.
Tags: , , , , , , , , , , , , , , , , , , , , ,
3 comments

Gerald Driggers, Monday, 9-21-15

http://archived.thespaceshow.com/shows/2557-BWB-2015-09-21.mp3

Your Amazon Purchases Helps Support TSS/OGLF (see www.onegiantleapfoundation.org/amazon.htm)

If you rate shows on live365.com, email me your rating reasons to help improve the show

Guest: Gerald Driggers. Topics: Artificial gravity & his Space Review Article “Reduced Gravity: The 400-kilogram gorilla in the room.” Please direct all comments and questions regarding Space Show programs/guest(s) to the Space Show blog, https://thespaceshow.wordpress.com. Comments and questions should be relevant to the specific Space Show program. Written Transcripts of Space Show programs are a violation of our copyright and are not permitted without prior written consent, even if for your own use. We do not permit the commercial use of Space Show programs or any part thereof, nor do we permit editing, YouTube clips, or clips placed on other private channels & websites. Space Show programs can be quoted, but the quote must be cited or referenced using the proper citation format. Contact The Space Show for further information. In addition, please remember that your Amazon purchases can help support The Space Show/OGLF. See www.onegiantleapfoundation.org/amazon.htm. For those listening to archives using live365.com and rating the programs, please email me as to why you assign a specific rating to the show. This will help me bring better programming to the audience.

 

We welcomed back Gerald Driggers to discuss his August 10, 2015 Space Review article, “Reduced Gravity: The 400-kilogram gorilla in the room.” You can read & download this article at www.thespacereview.com/article/2802/1. During the first segment of our 1 hour 42 minute discussion, Gerald talked about the old concept to put a centrifuge on the ISS but of course that never happened. Much of the first segment our guest and listeners lamented the lack of attention to mitigating problems caused by microgravity by developing some form of artificial gravity as the standard mitigation tool. Gerald referenced several studies in support of the need for artificial gravity, including one only a year or so old. Listeners asked him about minimizing travel time to a destination, say Mars, as a way of mitigating microgravity issues. We talked about that but Gerald pointed out that at the destination you would still be in a less than 1 G earth gravity environment so what then? I asked Gerald if being stuck in LEO for decades might have contributed to the lack of NASA progress in this area. Kelly sent in an email asking several things, including a question about spin rates. Kelly also wanted to know why artificial gravity had been ignored for so long, suggesting the possibility that advocacy groups disregard it. I did not support Kelly’s contention as I have done many Space Show programs with advocates pushing for artificial gravity and even coming up with their own plans on how to achieve it. Gerald was asked about tethers. His response triggered a lengthy email from Joe Carroll on the subject which I will post for Joe on the blog for this program, then Joe called the show in the second segment. Gerald was asked about artificial gravity work going on in other countries & with other government space agencies. He also talked about the need to really just test for Mars and lunar gravity given the relationship of these numbers throughout our solar system to other planets and moons.

 

In the second segment, Gerald talked about his science fiction book series, “Earth Mars Chronicles” plus the long scale settlement of Mars. At this point Joe Carroll called to talk about his email, tethers, and the artificial gravity issue. Don’t miss the fine discussion with Joe and Gerald they brought up many facts about the situation, the 2010 National Space Policy and more. Joe referenced the Fresno Underground Gardens as a possible example of underground living which he said would be necessary due to radiation. There would be no on the surface living. He also talked about the need for a colony to expand internally and the challenges in setting up an ecosystem on another planetary body. Joe introduced us to other issues such as the need for a gut bacteria study on the ISS and the differences between genders in reduced gravity though that information is not gathered. Given that Gerald described himself as a Mars guy, not a Moon guy, I told him about the New York Times Op-Ed that appeared today, “Let’s Not Move to Mars” by Ed Regis. You can read the article at www.nytimes.com/2015/09/21/opinion/lets-not-move-to-mars.html?smprod=nytcore-iphone&smid=nytcore-iphone-share&_r=0. If you do read it and I hope you do, make sure to read the comments as well. Dr. Doug was the next caller. Doug and Gerald also had an interesting discussion as Doug suggested there was no need to do artificial gravity experiments in LEO, instead go directly to the Moon and do them there. This of course presumes we are going to the Moon. I talked with Doug about this as I think returning to the Moon, as much as I would like to see it happen, is still an unsupported assumption, especially if we are looking for the government to do it. This opened up a discussion about the private sector with Gerald saying he thought progress was more likely coming from the private sector than NASA regarding the issues talked about today. I pointed out that if we had private Bigelow space stations and somewhat affordable launch, then we might see this type of research undertaken if it was in the interest of a company to do so. Doug and Gerald continued their discussion which you don’t want to miss. As the show was ending, Gerald told us about his new e-book coming out on Kindle for just 99 cents on October 1, “Martian Sniper.” From what he said about it, it sounds like a winner so be sure to download and read it.

 

Please post your comments/questions on TSS blog above. You can reach Mr. Driggers through me or his website, http://earth-mars.com.

 

 

 

Space Show Webinar, Sunday, 5-25-14 May 24, 2014

Posted by The Space Show in Uncategorized.
Tags: , , , , , , , , , , , , , , , , , , , , , ,
8 comments

Space Show Webinar, Sunday, 5-25-14

Partial Gravity, Tethers, Artificial Gravity

Joe Carroll, Dr. Jim Logan, Dr. John Jurist

http://archived.thespaceshow.com/shows/2249-BWB-2014-05-25.mp3 — Audio only

http://vimeo.com/channels/thespaceshow — Webinar Video

Guests:  Joe Carroll, Dr. John Jurist, Dr. Jim Logan.  Topics:  Partial/Artificial gravity, tethers, NASA, HSF & more.  Please direct all comments and questions regarding Space Show programs/guest(s) to the Space Show blog, https://thespaceshow.wordpress.com.  Comments and questions should be relevant to the specific Space Show program. Written Transcripts of Space Show programs are a violation of our copyright and are not permitted without prior written consent, even if for your own use. We do not permit the commercial use of Space Show programs or any part thereof, nor do we permit editing, YouTube clips, or clips placed on other private channels & websites. Space Show programs can be quoted, but the quote must be cited or referenced using the proper citation format. Contact The Space Show for further information. In addition, please remember that your Amazon purchases can help support The Space Show/OGLF. See http://www.onegiantleapfoundation.org/amazon.htm.  For those listening to archives using live365.com and rating the programs, please email me as to why you assign a specific rating to the show. This will help me bring better programming to the audience.  To see the video broadcast for this webinar, please go to http://vimeo.com/channels/thespaceshow.  Note that the audio only & video archive will be posted at the same time once the video is edited, processed, and uploaded to the Vimeo Space Show channel.  Joe Carroll has presentation material on The Space Show Blog which he referred to throughout our discussion so you may want to download the material or have it available to you when viewing the webinar.

We welcomed back to the program Joe Carroll to follow up on his May 2011 Space Show Classroom program on the same subject.  Our panel members included Dr. John Jurist and Dr. Jim Logan. All of us were part of the May 2011 program on this same topic.  During segment one of our 2 hour 10 minute webinar, Joe Carroll went over his background, interest, and experience in the subject dating back to 1981.  Joe discussed his recent work and updates including his concerns for the rotation rate, Coriolis effect & the absence of any substantial progress in the area.  He directed us to Slide 2 & the specific language used in the 201 US National Space Policy introduction.  Our guests talked about missed opportunities by NASA & others to do the essential research needed to confirm the gravity prescription for humans.  Our guests also talked about the amazing amount of unknowns regarding the effects of microgravity or Zero G on humans as we are a 1 G species.  The issue of space settlements came up & I asked our guests if we were jumping the gun pushing settlements when so much of the human factors work remains unresolved and even unknown.  Joe talked about two extremes in the approach to settlements.  He said one extreme was to simply prove issues by walking.  That is, just try it.  The other extreme was to do “endless research and studies,” a critique often mentioned by space advocates.  Jim pointed out that essentially knowing nothing about the Gravity Prescription despite 53 years of human spaceflight experience doesn’t rise to the definition of “endless research and studies.” Apollo was the walking theory for the most part.  Our guests then talked about NASA plans for an outpost as compared to a settlement, specifically for the Moon.  During this segment, we received several listener emails which the guests responded to.  During this time, Jim continued to state that it was essential that we know at least the basic outlines of the gravity prescription for humans for long duration interplanetary spaceflight.  Our guests talked about the ISS and the role it could play in supporting gravity research.  Joe continued to discuss more of his slides and our panel members had much to say about the discussion. Toni called at the end of the segment to ask about 1 RPM spin rate and mentioned that SpaceX said it wanted to go to Mars by 2020.  Here is the article Tony referenced:  http://www.dailymail.co.uk/sciencetech/article-2634046/Elon-Musk-says-SpaceX-making-progress-Mars-colony-2020-plans-sell-tickets-500-000.html.

In the second segment, we decided to hold the listener emails until the end of the broadcast to allow Joe time to finish his slides and state his conclusions.  We started off with Slides 6, 7 & 8.  Joe progressed to talk about the inflatable tunnel, some of the technical aspects including specs and diameters and why one was better than the others.  Joe continued taking us quickly through the slides but for those interested in the details, pay close attention to them or contact Joe as his email address is on his presentation material.  Joe spent some time this segment talking about doing Gemini-like tether experiments and he also referred us to Robert Walker’s work.  Robert is a Space Show guest from the UK who has done excellent work on the issue of partial gravity based on Joe’s work with tethers, etc.  Check out Robert’s paper at
http://www.science20.com/robert_inventor/crew_tether_spin_for_artificial_gravity_on_way_to_iss_stunning_new_videos_space_show_webinar_on_sunday-137070.  Don’t miss the links to the tether spin videos in his paper.  The subject of rocket reusability came up and again, Joe and our guests had much to say about this so don’t miss it.  Also in this segment, there was more focus on spin rates.  Joe took us through is conclusion slide which is Slide 20.  He talked about the difficulty in selling space as the next stuff and said one never launches with cutting edge hardware.  We then fielded second segment listener emails on a variety of topics, then we talked about people wanting to go to Mars with the just do it concept mentioned in the first segment.  Several Dr. Zubrin comments were used as illustrations along with SpaceX plans to do Mars by 2020.  All of our guests said there was a significant difference in a short trip to the Moon with Apollo where the decision was made to take the risk for a few days but that going beyond LEO for a long trip to Mars for example was a totally different thing altogether.  Jim used long duration sailing voyages as an example of how the issues for the crew once the long duration trips were started turned out to be very vastly different than for short, easy, turnaround ‘sortie’ voyages. Once transoceanic voyages were attempted it didn’t take Captains, crews or their respective patrons long to realize long duration voyages came with radical new levels of complexity and increased human risk.  We talked more about tethers as well.  Jim made the point that the average time spent on the Moon per Apollo lunar moonwalker was only 2.06 days, a woefully inadequate time to ascertain increased risk.  Joe also talked about the possible study & use of 0.06 G as explained in Slide 8.  I asked each guest for their concluding remarks, starting with Dr. Logan.  His take away was that it is critical to know the gravity prescription. Dr. Jurist was next saying there was no useless research and that gravity research may very well benefit us here on Earth in ways we can’t even imagine at this time.  Joe summarized his concluding thoughts per his last slide, talked about his possible plans to be more proactive with his work and suggested easy experiments that could be done with a Dragon and the spent first stage even on an ISS mission.

Please post your comments/questions on The Space Show blog above.  You can reach all of the guests through me but as stated earlier, Joe lists his email address on his presentation material.

Partial Gravity IAC2010 Presentation revised 2014May22

DesignConceptsForAMannedArtificialGravityResearchFacilityForIAC2010Sept14 rev 2014May22

Jackie Kingon, Friday, 10-26-12 October 27, 2012

Posted by The Space Show in Uncategorized.
Tags: , , , , , , ,
2 comments

Jackie Kingon, Friday, 10-26-12

http://archived.thespaceshow.com/shows/1881-BWB-2012-10-26.mp3

Guest:  Jackie Kingon.  Topic:  We discuss Ms. Kingon’s new book, “Chocolate Chocolate Moons” which is a humorous mystery on the Moon & Mars.  You are invited to comment, ask questions, and discuss the Space Show program/guest(s) on the Space Show blog, https://thespaceshow.wordpress.com. Comments, questions, and any discussion must be relevant and applicable to Space Show programming. Written Transcripts of Space Show programs are not permitted without prior written consent from The Space Show (even if for personal use) & are a violation of the Space Show copyright. We do not permit the commercial use of any Space Show program or part thereof, nor do we permit Space Show programs to be edited, placed on YouTube, or other private channels & websites. Space Show programs can be quoted in news articles, papers, academic & research work, but must be cited or referenced using the proper citation format. Contact Dr. Livingston for questions about our copyright and trademark policies.  We welcomed Jackie Kingon to the show to discuss her new and very funny book, “Chocolate Chocolate Moons.”  Jackie’s website for more information as well as the articles discussed near the end of the program is at www.jackiekingon.com. To order the book from Amazon & to have Amazon make a donation to The Space Show/OGLF, please use http://www.amazon.com/Chocolate-Moons-Jackie-Kingon/dp/1477561803/ref=onegiantlea20 or http://www.amazon.com/Chocolate-Moons-ebook/dp/B00954NGNK/ref=onegiantlea20. In our first segment, Ms. Kingon talked about why she wrote the book and the influences upon her from the Mars trilogy by Kim Stanley Robinson.  She explained her focus on eating, food, culinary treats, & more.  We read some passages & discussed the characters, especially Molly Marbles, the main character.  We talked about obese people going to the Moon to weigh 1/6th of what they do on Earth but they still look obese.  Molly is 287 lbs on Earth but only 47.6 lbs. on the Moon.  Molly gets to the Moon by winning a Good and Plenty Scholarship for two at the NeilArmstrongUniversity on the Moon. Molly got the scholarship based on being a plus-sized student and her “cholesterol readings, body-fat ratio, Fibonacci number sequence for digesting chocolate and high school cafeteria records.”  The story unfolds from there, goes to Mars, depicts a luxurious Martian hotel, and more.  Molly took her boyfriend Drew with her to ArmstrongUniversity but in short order, Drew dumped her.  Our guest talks about how she integrated real space facts into her story when available but she did not focus on rockets, propulsion, and transportation.  We also learn that while the Moon is the place for obese people, Mars for thin people.  Near the end of the first segment, Jackie talked about her art which you can find out more about by visiting her website.

In the second segment, we learned more about the mystery which is based on a poison in the Chocolate Moons.  Jackie tells us about some of the marketing issues for a book that falls in-between the science fiction and humor genres, especially in getting quality shelf space in book stores.  We talked about the luxurious Nirgal Palace Hotel on Mars, some of the other story characters, & the mystery surrounding the Chocolate Moons.  As our program was ending, we asked Jackie about her teaching experiences which she shared with us. Note that the two articles she mentioned are available on her website. Jackie said more about her art, especially in the Estee Lauder Collection.  Another item discussed was her naming of certain characters after famous historical people & characters.  Jackie is working on a sequel to the book which may become available during the next few years.

Please post your comments/questions on The Space Show blog above.  At the end of the program, Jackie does give out her email address for those of you wanting to get in touch with her.

Gary Hudson, Tuesday, 5-29-12 May 30, 2012

Posted by The Space Show in Uncategorized.
Tags: , , , , , , , , , , , , , , , , , , , , , ,
4 comments

Gary Hudson, Tuesday, 5-29-12

http://archived.thespaceshow.com/shows/1784-BWB-2012-05-29.mp3

Guest:  Gary Hudson.  Topic:  Variable gravity research station as a free flyer near the ISS.  You are invited to comment, ask questions, and discuss the Space Show program/guest(s) on the Space Show blog, https://thespaceshow.wordpress.com. Comments, questions, and any discussion must be relevant and applicable to Space Show programming. Transcripts of Space Show programs are not permitted without prior written consent from The Space Show (even if for personal use) & are a violation of the Space Show copyright.  We welcomed back Gary Hudson, President of the Space Studies Institute, to discuss the Space Studies Institute variable gravity research station program known as G-Lab.  You can read about G-Lab at http://ssi.org/2012/04/ssi-update-april-2012-introduction-to-g-lab.  To find out more about The Space Studies Institute, please visit http://ssi.org.  In our first segment, Gary Hudson provided us with an overview of the data points we have on the effect of microgravity on the human body dating back from the beginning of the space age.  If the goal is the permanent human expansion and settlement in space, we have very few if any data points, yet we need this information if we are to expand beyond short trips to the ISS or another turnaround lunar mission.  In terms of artificial gravity, we don’t know what levels humans require other than we know we are designed for 1 G.  As Gary pointed out several times during our discussion, the permanent settlement in space implies families, child birth, and the things that we do here on Earth but we are lacking any meaningful and relevant information to make this possible  The G-Lab concept is to be able to do long term properly designed centrifuge research in free flying labs around the ISS, doing animal studies in lunar, possibly Martian, and Earth gravity. The experiments would be long term, properly designed by researchers with NASA as well as other institutions.  Financing the project would be in segments and phases and involve the private sector & the public sector.  Mr. Hudson described five phases with the first three phases being privately funded while the last two a combination of public/private funding.  The Falcon Heavy is a possible launch vehicle but so are other launchers.

In our second segment, we started off with a listener question about a Space Review article suggestion the Dragon be used for microgravity experiments in support of a human Mars Mission.  You can read the article by Tom Hill at www.thespacereview.com/article/2089/1.  Gary commented on this but remained focused on their project supporting permanent settlement in space, not just a trip to Mars.  This is an important distinction so do listen to how Gary explains this difference.  Other listeners asked Gary questions based on other Space Show programs/guests dealing with genetic modification and the need to work with gravity here on Earth as we age.  Listeners suggested simpler experiments.  One person suggested using insects but Gary made it clear that animals with a backbone were essential for these studies.  As the segment was drawing to a close, Gary mentioned a few of the challenges other than funding including power, life support, human crew needs, keeping the lab animals healthy, and being able to carry out all the needed experiments.  We talked about funding and Gary mentioned philanthropic naming opportunities for the centrifuge labs just as donors name buildings at hospitals and universities here on Earth.  If you have comments/questions for Gary Hudson, please post them on the Space Show blog.

If you want to get in touch with Gary specifically for this project, you can e-mail him through their website by using the About tab, then selecting Officers and Board.

Drs. Adrian LeBlanc, Thomas Lang & John Jurist, Sunday, 5-6-12 May 6, 2012

Posted by The Space Show in Uncategorized.
Tags: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,
3 comments

Drs. Adrian LeBlanc, Thomas Lang & John Jurist, Sunday, 5-6-12

NASA Bone Loss & Bisphosphonate Study

http://archived.thespaceshow.com/shows/1769-BWB-2012-05-06.mp3

Guests:  CLASSROOM:  Dr. Adrian LeBlanc, Dr. Tom Lang, Dr. John Jurist.  Topics:  Bone loss issues for human spaceflight & the use of bisphosphonates for mitigation.  You are invited to comment, ask questions, and discuss the Space Show program/guest(s) on the Space Show blog, https://thespaceshow.wordpress.com and The Space Show Classroom blog, http://spaceshowclassroom.wordpress.com.  Comments, questions, and any discussion must be relevant and applicable to Space Show programming. Transcripts of Space Show programs are not permitted without prior written consent from The Space Show (even if for personal use) & are a violation of the Space Show copyright.  In addition, at the end of this summary, you will find links to relevant papers for our discussion as provided us by Dr. Lang.  We welcomed Dr. Adrian LeBlanc, Dr. Tom Lang and Dr. John Jurist as co-host to discuss the NASA bisphosphonate and bone loss study in progress.  Dr. LeBlanc along with his associate in Japan, Dr. Toshio Matsumoto, are leading this study and Dr. Lang is part of the team.  We started our discussion with Dr. LeBlanc providing us with a brief historical overview of bone loss issues of concern to NASA since the early days of the space program.  We talked about Skylab, Mir, the use of the DEXA scan, the use of quantitative computer tomography (QTC) and CT scans through to the ISS, Space Shuttle, and current research projects.  Our discussion was technical at times so if you need to look up or Google a technical term, please do so. In addition, we had some audio issues with the phone line used by Dr. LeBlanc as he faded in and out from time to time.  We apologize for any inconvenience this might have caused.  The first segment went through the bone loss issues, problems, consequences, & the methodologies involved in analyzing the conditions encountered by the astronauts participating in these studies.  Issues we discussed included the use of prescription drugs in space, long term use of bisphosphonates, risk factors for spontaneous hip fractures, exercise programs, bone strength, bone mass, the impact of radiation, skeletal recovery back on Earth after spaceflight to something different than before the spaceflight took place as well as the implications for astronauts as they age.  We talked about using artificial gravity to mitigate bone loss.  You might be surprised to learn that using partial gravity may not help matters.  Bisphosphonates do seem to help and will possibly play a role with exercise as we move to long duration spaceflight but we are in the very early stages of fact finding on these issues.  We also discussed informed consent with the astronauts regarding their participation in these and other experiments.

In the second segment, a listener asked about the relevance of this type of space research to the taxpayer who funds it and to the general population.  Our three guests responded to this question, explaining why the research is relevant and important. Don’t miss their answers.  We then talked about following the astronauts here on Earth to see the continued impact of having been in space on their bones as they age.  We learned that bone changes after being in space for four weeks or more and it is important to follow these changes as part of the aging process.  Our guests talked about calcium excretion issues in space and the risk this causes for a renal stones.  Bisphosphonates may inhibit calcium excretion which would help mitigate this risk.  Near the end of our discussion, we learned about new medications being developed that are more advanced than the bisphosphonates we have today.  We also talked about the competition with astronauts for different scientific experiments.  As Dr. Jurist pointed out, we really do need lots more human spaceflight!  At the end a listener asked about bed rest studies and our guests provided us with the basics.  If you are interested, visit https://bedreststudy.jsc.nasa.gov.  Our guests made important closing comments and take away points.

Please post comments/questions on The Space Show and Classroom blogs.

Dr. Lang provided us with these links that will be of interest to us all.  These documents can be accessed without a subscription to the journals. These papers provide some background to the problem of bone loss in spaceflight, the recovery of bone after spaceflight and use of CT and the use of CT-based finite element modeling to assess bone loss.

Cortical and Trabecular Bone Mineral Loss From the Spine and Hip in Long-Duration Spaceflight http://onlinelibrary.wiley.com/doi/10.1359/JBMR.040307/full

Adaptation of the Proximal Femur to Skeletal Reloading After Long-Duration Spaceflight http://onlinelibrary.wiley.com/doi/10.1359/jbmr.060509/full

Reduction in proximal femoral strength due to long-duration spaceflight http://scholar.google.com/citations?view_op=view_citation&hl=en&user=0zFSO9sAAAAJ&cstart=20&citation_for_view=0zFSO9sAAAAJ:4DMP91E08xMC

Click on link on right “[PDF] from http://cof.org.cn ” for free pdf copy of the report.

Dr. John Jurist, Tuesday, 3-27-12 March 27, 2012

Posted by The Space Show in Uncategorized.
Tags: , , , , , , , , , , , , , , , , , , , , , , ,
6 comments

Dr. John Jurist, Tuesday, 3-27-12

http://archived.thespaceshow.com/shows/1744-BWB-2012-03-27.mp3

Part 1, Bisphosphonate Usage in Microgravity

Guest:  Dr. John Jurist.  Topics:  This is the first in a series of programs focused on the use of bisphosphonates to mitigate bone loss in long duration spaceflight.  You are invited to comment, ask questions, & discuss the Space Show program/guest(s) on the Space Show blog, https://thespaceshow.wordpress.com. Comments, questions, & any discussion must be relevant & applicable to Space Show programming. Transcripts of Space Show programs are not permitted without prior written consent from The Space Show (even if for personal use) & are a violation of the Space Show copyright.  We welcomed back Dr. John Jurist for the first of several programs devoted to understanding bone loss in microgravity & the use of prescription the bisphosphonate family of drugs to mitigate the problem.  Dr. Jurist provided talking points which you can find below this summary on The Space Show blog.  A significant portion of the second segment is devoted to understanding these talking points so follow along.  We started our discussion with an explanation of the bone loss problem facing those in microgravity.  Following this brief overview, Dr. Jurist told us about bisphosphonates, the origins of this drug, how it was developed, how its usage, what some of the side effects are, some of the trials that have been associated with the drug, & space/NASA studies.  Later in this nearly hour long segment, we talked about the human population & what happens to our bone mass at various stages in our life. We talked about gender, racial, & ethnic differences in human bone mass issues.  As you will hear, there are gender & other differences among our diverse population.  This led us to asking about using targeted genetics in selecting crews for longer spaceflight missions.  Genetic modification was mentioned, especially for the long term, but for the near term, looking for better exercise routines & pharmaceutical modification/treatment seem to hold the most promise.  Dr. Jurist then talked about bisphosphonate side effects.  Fast transit time to Mars or a long duration mission destination came up. As you will hear, even if you get to Mars faster, you still have the problem on the surface of Mars.  The big problem is we have no credible information on what the gravity prescription for humans needs to be so we do not know if Martian gravity is sufficient to mitigate the problem.  Next, we focused on the need for an orbiting centrifuge, we talked about the size & spin rate of the centrifuge, & what to actually test for in experiments.  Dr. Jurist suggested that starting with 1/6th lunar gravity made sense because if it was sufficient, we would know that anything stronger than 1/6th would work.  If not, we should probably next experiment with Martian gravity which is about 1/3rd Earth gravity.

In our second segment, Dr. Jurist referred to his talking points which you will find on The Space Show blog. We went line by line so follow along with us.  Despite interruptions, John stayed on topic with the talking points.  Listener questions asked about how gravity & having a load on bones works & what happens in space when that load is no longer present.  We talked about the time prescription as well as the load factor (G force).  Toward the end, John told us about a reviewed radiation article from 2010 showing that radiation impacted bone loss so the issue in space is more complex than just microgravity.  Near the end, John got a question asking about ETs & their thin, pencil like shape making them perfectly designed for microgravity.  This was both an interesting & fun discussion, bordering on science fiction.  Another question asked about fish, reptilian, sea mammal, & bird bones.  Our final topic dealt with the release of personal astronaut medical information & others & the ways for private information to be legally released to the public.

Please post your comments/questions on The Space Show blog URL above.  Email for Dr. Jurist can be sent to me for forwarding.

________________________________________________________

Dr. John Jurist Bisphosphonate Talking Points:

Bisphosphonate show Tues 8:00-9:30 MDT Talking Points

Introduction:             Bone is incredibly complex with many inter-related factorsGoal:                          Brief outline of cellular, structural, and functional aspects of bone metabolism in order to help listeners better understand and appreciate the potential role of bisphosphonates (which is the subject of a future show)

Bone Function:          Two types of bone – compact and trabecular: Compact is outer shell, very dense, and fairly strong

Trabecular – also called spongy, contains spicules, plates, and struts of bone tissue with lots of vascular and fatty marrow, called trabecular

Remodeling:             Bone is constantly being turned over or remodeled with portions being torn down and constituents dumped into bloodstream and other portions being built up from nutrients supplied by blood

Very rapid bone loss can lead to kidney stone formation from calcium dumped into blood

Turnover rate and the volume of total skeleton undergoing remodeling at any given time tends to go down with increasing age (remember this – important)

Balance between formation and resorption (tearing down) also tends to be lost after about age 30, lack of activity, certain hormonal imbalances, diseases, etc. with resorption predominating – one rationale for estrogen replacement therapy after menopause

Coordination between formation and resorption partly controlled by mechanical strains on bone tissue (called Wolff’s Law and issue in microgravity) – some evidence that mechanism is electrical in nature – rationale for electric and electromagnetic bone growth stimulators used to treat problematic fractures and improve incorporation of bone grafts

Cells:                          Stem cells differentiate (or specialize) into osteoprogenitor cells which differentiate into osteoblasts which are the bone formers

Osteoblasts create and secrete a protein and polysaccharide matrix called osteoid which is then calcified later to form the stuff we call bone

Interference in that calcification leads to rickets in children and osteomalacia (Greek for soft bones) in adults

Osteomalacia is often a result of interference in Vitamin D metabolism or dietary deficiencies

During bone formation, some osteoblasts “paint” themselves into a corner and get surrounded by bone – they are then called osteocytes and somehow maintain bone tissue

If osteocytes die in a volume of bone, that devitalized bone no longer undergoes remodeling but can eventually be replaced by a process called creeping substitution (remember comment about remodeling volume going down with age)

Devitalized bone can accumulate fatigue defects and eventually suffer fatigue fractures (called stress fractures – common in military recruits and deconditioned people who recondition too rapidly) if the defects are not replaced by new bone during creeping substitution

Other cells, with multiple nuclei and called osteoclasts, differentiate from marrow cells (monocytes and macrophages) which in turn differentiate from stem cells

Osteoclasts are the bone resorbers and destroyers

Autoradiographic studies show that their nuclei also came from osteocytes as well – presumably as they are resorbed during bone destruction process

Osteoclasts are related to multinucleated “giant cells” which are associated with inflammation in ways I do not understand

Bisphosphonates:      Used over past 20-30 years in clinical medicine – brands include Actonel, Boniva, Fosamax, Aredia, etc.

Multiple mechanisms with different dose-response properties results in clinicians juggling doses and brands to get effects they want without effects they do not want

Bind to hydroxyapatite – the mineralized  portion of bone tissue (calcified osteoid)

Inhibit bone resorption by inhibiting osteoclastic activity

Inhibition of resorption signals osteoblasts to slow down formation rates after a delay (but increases their lifetimes (anti-apotosis)

Bisphosphonates also inhibit mineralization of osteoid – especially at higher doses

That eventually reduces turnover rate and can lead to fatigue fractures with prolonged treatment (remember to call 1-800-BAD-DRUG)

Orthopedic surgeon (Frost atHenryFordHospital) figured out that cyclic therapy exploits delay in osteoblast inhibition relative to osteoclast activity and results in better bone mass gains

Bisphosphonates used in oncology to preserve bone and reduce pathological fractures with osteolytic tumors such as breast and prostate cancers.  Also to counter hormonal blocking therapy used for prostate and breast cancers, but side effects increase with duration of treatment

Interesting sidelight with oncology is some evidence that bisphosphonates reduce risk of tumor metastasis to bone and other sites (somehow involving same signaling pathway as giant cells?)

Oral bisphosphonates cause stomach upset – advise staying upright for an hour or two after taking pill – how does this affect microgravity exposure?

Intravenous bisphosphonates get around oral gastric upset, but placing line or port has risks too (most oncology patients have ports during active treatment)

Also cause osteonecrosis – especially jaw which I believe is septic or infective – and atrial fibrillation (talk to Bill Rowe on this one since he is interested in heart physiology in space)

Bone quality:             Turnover rates and percent of skeleton not devitalized important factors in determining bone strength – measuring bone mass by DEXA or other means is not the be all and end all in evaluating bone strength and risk of fracture.

My Goal:                   General background on bone physiology and function to aid in appreciating upcoming show(s) on bisphosphonates in space medicine

John Batchelor “Hotel Mars,” Wednesday, 12-7-11 December 8, 2011

Posted by The Space Show in Uncategorized.
Tags: , , , , , , , , , , ,
3 comments

John Batchelor “Hotel Mars,” Wednesday, 12-7-11

This segment features Mr. Batchelor,  Dr.Space and Dr. John Jurist discussing bone loss in space

http://archived.thespaceshow.com/shows/1668-BWB-2011-12-07.mp3

Guests:  John Batchelor, Dr. David Livingston, Dr. John Jurist.  Topics:  Bone loss issues for short and long duration spaceflight.  You are invited to comment, ask questions, and discuss the Space Show program/guest(s) on the Space Show blog, https://thespaceshow.wordpress.com.  Comments, questions, and any discussion must be relevant and applicable to Space Show programming. Transcripts of Space Show programs are not permitted without prior written consent from The Space Show (even if for personal use) & are a violation of the Space Show copyright. The Space Show/OGLF is now engaged in its annual fundraising drive. Please see & act upon our appeal at https://thespaceshow.wordpress.com/2011/11/21/space-show-2011-fundraising-campaign.  As many of you know, I have been doing a weekly segment on the John Batchelor Radio Show with Mr. Batchelor on various space topics.  Sometimes I appear with John as the only guest on the segment, at other times I co-host the segment with John and bring on board an expert in the subject being discussed. Mr. Batchelor has given The Space Show permission for these segments to be archived on The Space Show site and blog.  Mr. Batchelor calls these segments “Hotel Mars” and they are targeted toward his significant live and podcast highly educated general audience.  Find out more about the excellent John Batchelor Show and listen to his archived segments at http://johnbatchelorshow.com.  You can hear the live stream of his show if it is not carried live in your radio market at www.wabcradio.com/article.asp?id=531472.  For this segment of Hotel Mars, we discussed bone loss in space and the use of the class of drugs known as bisphosphonates in treating bone loss issues.  This discussion was prompted by various news reports such as this one:  www.dispatch.com/content/stories/national_world/2011/12/06/osteoporosis-drugs-helped-astronauts-scientists-say.html.  Our special guest was Dr. John Jurist and I co-hosted the segment with Mr. Batchelor.  During our eleven minute segment, we addressed bone loss issues for both short duration and long duration spaceflight.  We talked about the use of bisphosphonates, the benefits and the risks associated with them.  We also addressed artificial gravity, issues of both lunar and Martian gravity, and the seriousness of the bone loss issue as well as the other human factors issues primarily for the longer duration voyages.  Post any comments/questions that you might have regarding this John Batchelor Show segment on The Space Show blog URL above.  We thank Mr. Batchelor for allowing us to archive this segment on The Space Show website and blog.  Please note that the copyright to this material remains with The John Batchelor Show.  Any and all uses of this material must be approved by John Batchelor.