Broadcast 3539 Dr. Alan Stern

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The Space Foundation Conference

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Guest:  Dr. Alan Stern;  Topics: Multiple topics including New Horizons, Pluto, the Kuiper Belt, propulsion, nuclear power, searching for life, space settlement, planetary missions, NASA & scientific priorities plus much more.

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We welcomed Dr. Alan Stern back to the program for a one segment 90 plus minute multiple topic discussion.  Note that to avoid breaking the discussion flow and caller participation, we omitted the break and I did not read sponsor messages.  Our sponsors are very important for us so let me now thank each and everyone of them:  Northrop Grumman, The Space Foundation, Astrox, AIAA, Moonwards, Celestis, The National Space Society, and The Space Plan.  We would not be bringing you these programs were it for the very important ongoing support afforded TSS by our great sponsors. If you are interested n being a Space Show sponsor, please email me at  Remember, sponsor messages are on the archived programs so your message is heard every time the program is played in all formats for years to come. This is a very affordable and more than efficient way to get your message in front of thousands of interested industry and related folks. 

Alan started the discussion by letting us know that New Horizons was coming up on its Fifth Anniversary, July 14!  That opened the door to start talking about New Horizons, the data it has sent back to Earth and more.  Our guest talked about the quantity of data received from New Horizons, that fact that all of it has been received, he mentioned how much time it took to transmit and download it and the science being done as the findings are researched and studied.  This was a most interesting discussion so don't miss it as much more was said about the New Horizon findings and studies.

As I have been doing with other archived programs, one of the best ways to briefly summarize the program, mostly in the order discussed, is to copy the Tags/Key Words right here in the summary.  Here they are: 

Pluto, New Horizons spacecraft, the Kuiper Belt, New Horizons 5th anniversary, New Horizons data evaluations, Pluto orbital mission, Pluto is or is not a planet, planetary science, future New Horizons targets in the Kuiper Belt, Arrokoth, RTGs, plutonium, Nuclear Power, Killopower, New Horizons power time line, subsurface Pluto ocean, Pluto heat source, Enceladus, Europa, Eris dwarf planet, Delta V to orbit Pluto, RTG batteries, Pluto lunar tidal forces, New Horizon compared to Mars rover popularity, Cassini, RTG Plutonium 238 limits, smaller nuclear reactor designs, New Horizons speed as a variable, New Horizons parallax experiment, Public Private Partnership, Artemis, lunar return, settlement, solar power, chemical rockets, ion power. 

Alan received multiple listener phone calls and emails during the program so many of the topics and matters discussed were listener generated.  A few of the discussions stood out such as when Alan was asked the question if New Horizons confirmed that Pluto was a planet.  This question got a big response from Alan that was also fun.  Make sure you hear all of it.  Nuclear power and the use of RTG's also got a big discussion.  Don't miss what was said about spacecraft power including chemical, solar, ion and nuclear.  In addition, there were multiple conversations about the Kuiper Belt, other Kuiper Belt objects, additional New Horizons targets, and searching for life.  Note what Alan said about Europa, Enceladus and the possibility of something akin to life in the subsurface Pluto oceans. 

Public Private Partnerships as a way going forward played a role in our discussion, especially when Alan was asked for his personal opinion about Artemis.  While providing us with his Artemis opinion, note what he said about human spaceflight, settlement and the need to return to the Moon.   While I mentioned Alan's RTG discussion above, Alan provided us with the specifics of the half-life decline re NH power in wattage over the life of the spacecraft.  I thought this was very interesting and had not heard or come across this information before.  Before moving on, lot's was said about other Kuiper Belt objects and selecting another flyby target for NH.  Both Arrokoth and Eris were talked about in some detail.

Ft. Worth John had an interesting question for Alan, asking him about the Delta-v needed to orbit Pluto.  Don't miss how Alan answered John's question plus the fact he provided for us all.  John also asked about the source of heat on Pluto re the subsurface ocean.  You don't want to miss how our guest responded to that question.

As we were nearing the end of our program, I asked Alan if NASA or anyone else collected stats on the popularity of NH as compared to Mars rover missions.  Alan had much to say about that, using Curiosity as an example.  He also talked about the upcoming Mars 2020 mission, NASA PR and outreach in general and I talked about Space Show experience with different NASA officials talking about key planetary and solar system missions.  We would like to know your thoughts on these topics so post on our blog.  Rick sent in a near end of show email about limits to RTG usage due to Plutonium 238 limitations.  Alan discussed this issue in some detail so once again don't miss what our guest had to say.  This opened up an additional nuclear reactor discussion with a note from Marshall specifically asking about small reactors for spaceflight. 

Final topics including asking Alan if the speed of New Horizons could be increased and if so, would it be beneficial.  We discussed future planetary missions and wondered if increasing the budget for such missions was the key factor in doing more missions.  Be sure to hear what Alan said in response to these questions.  We then moved toward the summary with a question for Alan about his upcoming participation in the NSS A Day In Space Program set for July 18 plus, a question about additional NH parallax experiments and key events for NH that will be upcoming later this year and next year. 

Please post your questions/comments for this program on our blog for this show.  Dr. Stern can be reached through me, The NH website plus his website,, or his Southwest Institute Boulder website.




Pluto, New Horizons, Kuiper Belt and more

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12 Jul 2020 Dr. Alan Stern
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