Broadcast 3503 Dr. Pekka Janhunen

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Guest:  Dr. Pekka Janhunen;  Orbiting space settlements, O'Neilian space colonies, 1 g settlement, shielded dumbbell settlement concept at L5 and more. 

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We welcomed Dr. Pekka Janhunen from Finland to the show to discuss his three papers published on the NSS Space Settlement Journal website,  We spent most of the time discussing the most recent paper by our guest, "Shielded Dumbbell L4 Settlement" (see  In addition to our primary focus on his latest paper, we discussed the two earlier papers published by our guest on the same website as we move into the latter part of the second segment of the program.  Our program was a 1 hour 45 minute discussion over two segments with my reading sponsor messages between the first and second segment.  I certainly urge you to read the Shielded Dumbbell paper by our guest as we spent a considerable amount of time discussing this concept.  Reading the paper will enable you to follow along as we did not talk about all of the details relating to this concept. 

As stated above, most of the first segment was devoted to orbiting space stations per the O'Neilian concept, the establishment of one g on the orbiting station, and dumbbell concept as explained in Dr. Janhunen' s paper.  We covered many related topics such as why 1 g, comparable settlements on either the lunar or Martian surface, solar power compared to nuclear power, radiation shielding, microcavity issues particularly on a planet's surface since it would be hard to establish 1 g on the surface of either the Moon or Mars,  plus much more.  Our guest went into detail describing the physical size and characteristics of his orbiting space settlement, how much space each person would have, plus construction details and materials needed. 

Listeners brought up life in a centrifuge questions, cosmic rays and shielding, magnetic field concerns, plus Fremont John called to inquire about the cost for the settlement which was estimated at $300 per kg.  I asked our guest about TRLs for actually building such an orbiting platform settlement along with asking for a plausible timeline.  By the way, TRLs were suggested but for the most part our guest said we were around a TRL 3 at the present time. For other parts of the orbiting settlement, Pekka estimated the TRL to be about a 1.  Listen to all of what he said about our technology readiness at this time on into the near to medium range future.

Todd got in a question asking about private sector or government involvement or government and which did he prefer.  This led to questions about economic returns and payoffs for private companies engaged in building the settlement.  The subject of settlement sustainability came up with our guest saying there would have to be children on the settlement. Listeners and I brought up questions about children in space, then pregnancy and infants in space.  Our guest mentioned ethical and other concerns in this area but do listen to all of what he said to get the full picture. 

We ran through the break with my delaying sponsor messages until the end of the program.  Pekka brought up lighting from his other paper about natural illumination. He talked about needing Earth day and night lighting, the preference and use of LED lighting, then he talked about maintaining CO2 levels which was the subject of his other paper mentioned earlier in this summary and in the key words.  Listener Judd asked about nuclear power instead of solar power.  Pekka then talked about why we want the station to be near Earth.

Listener Randy provided us with a change of pace question by asking if there was any market demand for an O'Neilian space settlement.  Our guest talked about costs, a type of condominium business model since he said the settlement residents would build other settlements and make money doing that and selling them.  Listen to his economics.  Tell us what you think by posting on the blog.

As we were approaching the end of the discussion, we did a comparison of a settlement on the Moon, one on Mars and then the free space concept.  Listener Joe in Dallas asked about space in Finland.  Fremont John called back to mention the economics put forward by the plans developed by Al Globus for his LEO low radiation settlement which he has presented many times on TSS.  Pekka went back to talking about the need to regulate and adjust CO2 in the settlement. 

Please post your comments/questions on TSS blog for this show. Our guest can be reached by email through the footnotes of his papers published in The Space Settlement Journal mentioned earlier in this summary as well as through The Space Show.




"Shielded Dumbbell L5 Settlement" Concept per

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01 May 2020 Dr. Pekka Janhunem
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