Broadcast 2249 (Special Edition)

25 May 2014 Joe Carroll, Dr. John Jurist, Dr. Jim Logan
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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, 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 For those listening to archives using 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 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: 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 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.



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