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Dr. Jim Dewar, Sunday, 12-6-15 December 7, 2015

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Dr. Jim Dewar, Sunday, 12-6-15


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Please download and read Dr. Dewar’s paper here:  a-technical-note-on-nuclear-rockets-1-2

Guest:  Dr. James (Jim) Dewar.  Topics:  The nuclear rocket, changing the paradigm to use it for economic growth to LEO.  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 Dr. Jim Dewar to the show to discuss his plans for the use of nuclear rockets specifically from Earth to LEO.  In addition, Jim’s book (it is out of print) “The Nuclear Rocket: Making Our Planet Green, Peaceful And Prosperous” is being made available as a Space Show fundraiser and we thank Jim for this great gift.  You can get a new paperback autographed copy of this book for a $50 contribution to The Space Show.  Please make your contribution using Pay Pal on TSS or OGLF websites or mail a check to TSS as instructed on the donation page of the websites.  Also, send me an email telling me your $50 contribution is for Jim’s book, provide your full name and your mailing address.  I need this email to know you want the book in exchange for your donation.  As of the time I am archiving this show, I have only ten remaining copies of the book to give away so act fast as once they are gone, this offer ends.  During the first segment of our two hour show, Dr. Dewar outlined his plan to break the nuclear rocket ban on using a nuclear rocket from Earth to LEO.  Jim spent some time explaining the history behind this ban which is not law!  The ban came to be in 1960 as a result of a luncheon meeting.  Listen to his telling of this story.  Do you find all of this frustrating?  I asked Jim how nuclear propulsion would work from Earth to LEO.  As you will hear, he said it was applicable to second or third stages on the rocket, not the first stage of the rocket.  He explains this in detail so don’t miss it.  Most of the first segment was devoted to discussing this ban, the early nuclear rocket history and tests, questions about the Soviet Union nuclear rocket program, the U.S. Congress, and cost comparisons with chemical rockets figuring in the cost for permits, dealing with protestors, time delays, etc. Jim also explained the economic benefits of his unique public private partnership he wants to see created to do nuclear propulsion to LEO and why.  His methodology for making this happen is potentially doable.

In the second segment, we continued talking tech about the nuclear rocket including core issues, the possibility of gas cores, specific impulse for the NTR, then a question came in about supporting the NewSpace agenda of NASA supporting space settlement and low cost space access.  He was asked if the NTR plan he was proposing supported these NewSpace goals.  Don’t miss what he had to say about this as I believe it was an important part of the discussion.  Jim repeated often during the show that as a nation we were nearly $20 trillion in debt and bankrupt. He then explained the economics of his program and why they would benefit NASA and the country in this challenging economic time rather than be deleted as a program that was just too costly.  Quite the opposite, he stated his program was made to order for these tough economic times.  See if you agree.  I do and we talked about it some more at length as we neared the end of our program. I suggested a sales approach that was much broader than just the space industry.   John in Ft. Worth called to discuss many technical issues and core temperatures.  BJohn wanted to know if the NTR should be reusable and refuelable.  Joe wanted to know how to start the program to advocate the public private partnership Jim was talking about and which he fully describes in his book.  Comments came up regarding Dr. Zubrin and the nuclear salt water rocket,  (see http://path-2.narod.ru/design/base_e/nswr.pdf).  Near the end of the show when we were talking about creating the needed policy for the partnership, Dr. Dewar referenced Admiral Rickover as a model for the type of leadership needed to make the NTR project happen.  As the program was ending, questions came up about Thorium and U233.

Please post your comments/questions on TSS blog per above.  You can reach Dr. Dewar about his first book or anything else through me at drspace@thespaceshow.com and I will send you his email address or forward your note.


1. Paul - December 12, 2015

I personally don’t think you will convince anybody to launch a nuclear reactor through the atmosphere. In fact governments around the world are abandoning the use of nuclear reactors for electricity generation.
If what Elon Musk and others are doing is successful then that will reduce the cost to low Earth orbit dramatically, as basically you only need the cost of the fuel.

jim dewar - January 10, 2016

The flight scenario going to and from LEO with NTR hasn’t been studied for over 50 years. If you read my second book, The Nuclear Rocket, you will read a policy argument for why it makes sense, basically it opens space up to the common man and it is a real money maker for everyone, including the greens. I hold that people will accept risk if the reward is great enough. Been true throughout human history and see no reason why it won’t be true in the future. As far as governments abandoning nuclear power, we’ll see. The shortcomings of wind and solar are becoming more evident every day and coal is a non-starter. So what does that leave you? Natural gas, dams. As far as Elon Musk is concerned, we’ll see. Everybody was elated over the space shuttle when it first flew. How did that work out?

2. Fremont John - December 12, 2015

Dear Dr. Dewar,

If we are to start advocating for the nuclear rocket launch system proposed in your book we will have to convince the environmentalists opposed to the use of nuclear materials on Earth and in the atmosphere that the system is safe. I read your arguments in the Technical Note on Nuclear Rockets from 2010 and they sound convincing…to me. I’m concerned that the fear of anything “nuclear” is so ingrained in the public psyche that it may be difficult to overcome.

I remember the hysteria and the protests from the Greens against the use of RTGs on Cassini. This is what we will be up against. I’m wondering if any of the risk analyses or engineering studies performed by NASA on the potential failure of RTGs during the possible reentry of Cassini in the Earth’s atmosphere upon gravity assist could be utilized? Are you aware of any such studies and would they be relevant (granted, your cocoon was not being evaluated in this case).

I really like the idea of siding with the Greens instead fighting them. Winning them over to our side will be challenging but it is essential to public acceptance of this concept.

3. Fremont John - December 10, 2015

Dr. Dewar
Sorry I missed the show. Was looking forward to your appearance for quite some time but was out of town on business so couldn’t call and had to catch the podcast.

Near the end of the show you were talking about next steps regarding further studies. I mentioned to David on the show a couple of weeks ago that I heard that NASA has just awarded contracts to a couple of American companies to study advanced propulsion for deep space exploration. One of these was development of “nuclear thermal propulsion to enable rapid transport of crew to Mars”. Here’s a link to the article:


I wonder if they will be looking at the same technologies as the B4 Core you described? Even though NASA banned nuclear rockets as launch vehicles in 1960, if the studies will help develop similar concepts maybe they could be applied to launch vehicles when your yet-to-be- named champion advocate gets the ball rolling on changing policy and shifting paradigms. Sign me up!

My wife is buying me your Nuclear Rocket book for Christmas. I’ll get educated and start carrying the (nuclear) torch!

4. Andy Hill - December 8, 2015

I wonder how much prototype work could be done without actual fuel rods. Possibly using some sort of externally powered heating element in place of a core to rough out a design before moving to actual nuclear material?

jim dewar - January 10, 2016

It was done back in the ’60s and is called electric furnace testing. If you have my first book you can read about it in the fuel appendix. Basically, furnace testing was useful, but lacked the nuclear environment so data derived from it was always good, but questionable. Later, the program moved to the Nuclear Furnace, which was a very small reactor designed to test fuel elements only in a high radiation environment. Any restarted program probably would make use of them, since they were designed with a “scrubber” to remove radioactivity from the off-gas hydrogen.
Hope this helps.

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