Broadcast 3146 Dr. Robert Reynolds

  • The Space Foundation Conference

  • The Space Foundation Conference

  • The Space Foundation Conference

  • The Space Foundation Conference

The Space Foundation Conference

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Guest:  Dr. Robert Reynolds;  Topics:  Astronaut/Cosmonaut competing mortality risks, space explorers and mortality, understanding statistical research & assumptions.  Please direct all comments and questions regarding specific Space Show programs & guest(s) to the Space Show blog which is part of archived program on our website,  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

We welcomed Dr. Robert Reynolds back to the program for a 2 segment 90 minute discussion regarding his latest published work on "The Mortality of Space Explorers" which is now a chapter in the INTECH free online book, "Into Space: A Journey of How Humans Adapt and Live in Microgravity" edited by Thais Russomano and Lucas Rehnberg.  In addition, Dr. Reynolds along with co-author Steven Day has published a new paper, "The effect of competing risks on astronaut and cosmonaut mortality."  These papers and the book chapter have links to them posted on the blog.  I urge you to become familiar with this material and follow along with us as Dr. Reynolds refers to specific tables, charts, grafts, and paragraphs in his discussion.  You can find more of the work for Dr. Reynolds at

During the first segment of our two segment program, Dr. Reynolds told us how and why he got interested in space from an early age and then made it part of his career.  I asked him to explain what was meant by the term "competing risks" since we were about to discuss his paper, "The effect of competing risks on astronaut and cosmonaut mortality."  Per the abstract of his paper, "The data do not support the hypothesis that observed reductions in mortality from natural causes are due in whole or in part to bias created by deaths from external causes at young ages. The data imply that reports of cause-specific mortality for astronauts and cosmonauts may in fact systematically overestimate mortality rates through these findings should be interpreted with caution as they data are thin at the extremes of follow-up time."  Most of the first segment was devoted to this discussion with multiple email questions from the listeners.  Please note that this is a complex but important topic and our discussion while short, was thorough.  Please don't miss it plus have the papers referenced above available so you can follow along with his tables, charts, paragraphs, and graphs.  Also note the categories and classifications used in data collection and analysis.  The small sample size of the number of people having gone to space was and still is an area of great concern.  This was especially true for the number of astronauts having been to the lunar surface. 

Several listeners brought up Mars and wanted Robert to extrapolate from his studies to suggest mortality for going to Mars.  He talked about two of the major risks, radiation and microgravity but other risks were brought.  Also the difference between the acute risk and the long term risk. 

During this segment, the fitness and screening that would probably be applied by private companies to general public astronauts/space visitors was brought up.  Don't miss what our guest said regarding this topic.  Later, I asked Robert if we could effectively screen people for finding future problems or broad risks.  Don't miss what our guest said about this type of screening.  Our guest brought up the Integrated Medical Model which he explained.  Regarding space settlement our guest talked about the usefulness of god analogs.  We then took a blog question from BJohn wanting to know if there were any health benefits for being space.  Don't miss what our guest said in response to this question. He mentioned analogs such as coal mining re lunar dust and other situations and things we know quite a bit about here on Earth that we could apply and extrapolate to spaceflight.

In the second segment, we talked more about the general population going to space, fitness condition, studies, and how best to evaluate this segment for spaceflight.  The Assumption of Risk by the spaceflight participants was discussion but also discussed was the idea of enforcing specific standards should there be a possibility of the mission being ruined by a general public participant with a condition that possibly should have been screened for and excluded due to the condition. 

Listener Randy wanted to know about artificial gravity.  Our guest said we should do it but that it was not clear what the long term artificial gravity would do in microgravity.  Listener Carolyn in Seattle wanted to know about gender, race, ethnic, and other potential differences.. Here, our guest had much to say.  He again noted the very small sample size which makes conclusions difficult.  He noted that about 85% of those having gone to space are white males and there does not seem to be lots of differences. Our guest noted some ethical issues in doing this research but then noted once again the small sample size. 

Listener Ben asked questions about understanding statically based reports.  He asked for guidance to avoid being misled by people who use statistics incorrectly, have created bad surveys and more.  The recent Pew study about the public's thoughts on NASA, going to Mars and related topics was mentioned as reference for Ben's question.  Listener Allan asked about Mars and wondered just how useful the analog studies were, including those that attempted to address microgravity through bed rest studies and then the radiation studies.  Don't miss what Robert had to say about Mars and understand statistical reports and media reporting statistical analysis and conclusions.

As the program was coming to a close, Robert was asked about Earth microbes contaminating Mars or bringing back something dangerous from Mars to Earth.  He said Mars was not a biological eco system but it was prudent to act with caution in bringing samples directly back to Earth.  Don't miss all of his comments on this subject.  Before the program ended, I asked our guest what he was currently working on regarding space related studies.  Then I asked about study sample size since that issue had come up several times during the show.  He said a better sample size for the space studies would be 5-10,000 study participants.  As for now, we have around 350.

Please post your comments/questions on TSS blog for this show.  You can reach our guest through his website above or me.




"Into Space" about microgravity and more

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06 Jul 2018 Dr. Robert Reynolds
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