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Tabitha Smith, Gwyn Rosaire, Project Bifrost, Sunday, 12-16-12 December 16, 2012

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Tabitha Smith, Gwyn Rosaire, Project Bifrost, Sunday, 12-16-12


Guests:  Tabitha Smith, Gwyn Rosaire.  Topics:  Nuclear propulsion, Project Bifrost, Icarus Interstellar.  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. We welcomed Tabitha Smith and Gwyn Rosaire to our program to discuss Project Bifrost and nuclear space propulsion.  For more information and to contact our guests, visit www.icarusinterstellar.org/projects/project-bifrost. If you are interested in joining Project Bifrost, or have suggestions, please use the “here” email link on the webpage. During our first segment, Ms. Smith started by giving us the origin and meaning of the project name, Bifrost (pronounced BEEFROST).  This discussion included Icarus Interstellar and mention of the Darpa 100 Year Starship Program (100YSS).  I asked Gwyn about our technical status in having a nuclear thermal rocket and he said we had more of an economic problem with nuclear propulsion than a technical problems.  We talked about the lack of a mission for a nuclear rocket and that such a mission would be generated from the White House on down.  Nuclear fuel was a topic as new research is focusing on tungsten fuels rather than graphite though our caller Dr. Jim Dewar suggested new opportunities existed with modern graphite fuels.  Other listeners emailed in both questions and comments about fuel.  Another topic included a discussion about a much larger payload to Mars with a nuclear thermal rocket (NTR) than a chemical rocket so I asked our guests about economic trades as to what would eventually be less costly, multiple chemical rocket launches or the use of a NTR.  Using the Saturn V for our chemical rocket, We carried our analysis to the point of including additional launches to cover for a launch failure and also the human factors side in that a shorter trip means less radiation for the astronauts, thus less shielding and potentially less mass.  I think you will find this discussion and analysis most interesting, including the NRC equation for astronaut exposure to radiation. In Dr. Dewar’s call, he also talked about the B4 core concept & the progress made with NERVA.  We got emails from Bruce in Canada plus other listeners advocating private sector development, a change in ITAR, and the radiation policy changing after Fukushima per this article, www.world-nuclear-news.org/RS_UN_approves_radiation_advice_1012121.html, and the UN Scientific Committee on the Effects of Atomic Radiation (UNSCEAR).

In our second segment, Michael called in to ask about Russian outreach and the Russian nuclear propulsion program.  We then asked our guests for the future Project Bifrost plans.  We learned of several major issues.  One issue centered on U.S. export control. Our guests also noted that the Russian economy was actually gaining in strength and this might cause them to think its better to go it alone than team up with a weak international partner.  Other listener emails inquired about time lines for operation.  It was suggested that about ten years would be needed for the NTR if all goes well.  As for more routine Mars flights, it was suggested that it would take about twenty years after the first human flights to Mars to really have the program operational. We talked about the private sector and our guests suggested that the private sector will play a strong role in developing and using nuclear propulsion.  Moving on, the second project our guests mentioned had to do with ablation technology using NASA Ames facilities.  The third and final project mentioned was at Huntsville, the Decade Module 2 fusion project at Marshall.  During both the first & second segments, our guests talked about Jupiter radiation and magnetic shielding. John asked about this when he called in the second segment.  Doug inquired about Dr. Zubrin’s Mars plans & possible trajectories that could be used with the pros and cons for each. Bruce inquired about fuel vibration problems, then Tim called wanting to know about tours at the Marshall facility & the level of power needed for interstellar travel.  As we were ending, our guests said we needed breakthrough propulsion or new physics for interstellar travel. Both our guests left us with important closing comments relevant to Project Bifrost & nuclear propulsion for our future with space development.  Don’t miss what each had to say as we brought our discussion to a close.

Post your comments/questions on The Space Show blog.  You can email our guests through me or through the above website URL for Bifrost.

Dr. James Dewar, Sunday, 2-12-12 February 12, 2012

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Dr. James Dewar, Sunday, 2-12-12



Guest:  Dr. James (Jim) A. Dewar.  Topics:  Nuclear Thermal Rocket (NTR), changing paradigms to use the NTR from Earth launch, nuclear economics.  You are invited to comment, ask questions, and discuss the Space Show program/guest(s) on the Space Show blog, https://thespaceshow.wordpress.com.  Comments, questions, and any discussion must be relevant and applicable to Space Show programming. Transcripts of Space Show programs are not permitted without prior written consent from The Space Show (even if for personal use) & are a violation of the Space Show copyright.  We welcomed Dr. Dewar back to The Space Show to further discuss the Nuclear Thermal Rocket (NTR) and his paradigm changing approach to use the NTR to launch from Earth rather than using it only in space.  During this nearly 2.5 hour discussion, Dr. Dewar makes the case for the NTR based on probable economics, the previous history associated with NERVA, and the assumed benefits flowing to private companies engaged in public private partnerships along the lines Dr. Dewar described.  In the first segment, Dr. Dewar started out describing the existing barriers to using the NTR to LEO rather than only in space, plus he referred us to his 29 page introductory paper which is available on The Space Show blog for your download and review.  During this segment, we fielded many listener emails and calls wanting to discuss the NTR ISP, possible fuels, testing, and legal issues impacting the use of the nuclear rocket. Michael called and talked about the discussions for a new treaty, the Fissile Material Cut-Off Treaty (FMCT) and how that would adversely impact using the NTR.  Dr. Dewar talked about treaty issues over the years and suggested that treaties are not that easy to establish in this era while suggesting that they could also be modified.  Near the end of the first segment, questions about thorium came up as did questions about additional commercial uses for the nuclear engine here on Earth. 

In the second longer segment, we talked about winning over the public and the media.  Charles Pooley called in with a set of questions and we talked about reentry vehicles, highly enriched uranium, and more.  Jim described a Titan missile accident in Arkansas as an example of the safety controls even in a very large explosion.  Another listener asked about cooling and Jim told us about pulse cooling.  Dr. Dewar’s air launch idea was brought up again by another caller andMarshall sent in an email inquiring about the nuclear engine replacing coal in our terrestrial power plants to make electricity.  I asked Dr. Dewar about risk assessment for the nuclear rocket and reprocessing given terrorism, etc.  He said the reprocessed material would be carefully guarded but also weighed against the environmental risks associated with burying waste, burning it, or even dumping waste in the ocean.  Dr. Dewar was asked about using the nuclear rocket only in space rather than attempting to use it to launch from Earth.  He compared using it only in space to the Pony Express. Don’t miss his full response in replying to this question.  Later in this segment, I asked Jim for his first step in advancing the NTR.  He said the first step was to get people talking about the subject.  Tom called in and also wondered how to get people to rally to the cause.  Near the end of the program, Jim talked some more about potential economic benefits along with secondary commercial products such as heat pipes.  As our program was ending ion engines came up as did Vasimr.

Please post your comments/questions on The Space Show blog.  If you want to contact Dr. Dewar, send your note to me for forwarding.

To download and read Dr. Dewar’s paper, see below:

A Technical and Economic Introduction to Nuclear Rockets

A Technical Note on Nuclear Rockets-1


The John Batchelor Show, “Hotel Mars,” Wednesday, 1-25-12 January 26, 2012

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The John Batchelor Show, “Hotel Mars,” Wednesday, 1-25-12

Project Icarus, Nuclear Thermal Rockets, Project Bifrost


Guests: John Batchelor, Dr. Richard Obousy, Dr. David Livingston. Topics: Project Bifrost, nuclear thermal rockets, Project Icarus.  You are invited to comment, ask questions, and discuss the Space Show program/guest(s) on the Space Show blog, https://thespaceshow.wordpress.com. Comments, questions, and any discussion must be relevant and applicable to Space Show programming. Written transcripts of Space Show programs are not permitted without prior written consent from The Space Show (even if for personal use) & are a violation of the Space Show copyright. This program is archived on The Space Show website, podcasting and blog sites with permission from John Batchelor. Please visit the John Batchelor Show website for more information about this fine program, www.johnbatchelorshow.com.  The topics in this 11 minute plus segment focused on Project Bifrost, nuclear thermal rockets, and Icarus Interstellar with Project Icarus.  Dr. Obousy expanded on these topics, the issue of interstellar flight and even some timelines looking off into the future.  Please visit  www.icarusinterstellar.org for more information. This is one of many excellent articles on Project Bifrost:  http://news.discovery.com/space/project-bifrost-interstellar-space-fission-120120.html.  Please post your comments about this segment on The Space Show Blog URL above.  If you want to send a note to Mr. Batchelor or Dr. Obousy, please do so to me at drspace@thespaceshow.com and I will forward it to them.

Dr. Steve Howe, Tuesday, 1-24-12 January 25, 2012

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Dr. Steve Howe, Tuesday, 1-24-12


Guest:  Dr. Steven Howe.  Topics:  space nuclear power for power & propulsion systems, & radioisotope power generators. You are invited to comment, ask questions, & discuss the Space Show program/guest(s) on the Space Show blog, https://thespaceshow.wordpress.com.  Comments, questions, & any discussion must be relevant & applicable to Space Show programming. Transcripts of Space Show programs are not permitted without prior written consent from The Space Show (even if for personal use) & are a violation of the Space Show copyright.  You will want to follow the websites along with our guest:  http://csnr.usra.edu/index.html &  www.usra.edu.  If you are interested in the CSNR 2012 Summer Fellowship Program, you can learn more & apply no later than March 9, 2012  from CSNR at  http://csnr.usra.edu/2012_summer_app2.html.  We welcomed Dr. Howe to the program to discuss space nuclear power.  We started out with an overview of both the Center for Space Nuclear Research & the Universities Space Research Association.  Dr. Howe then told us that they were working on nuclear rockets with the Aerojet Corporation, focusing on a new fuel form away from based on tungsten.  During our discussion, he had much to say about this fuel, its advantages, & its testing.  He also talked about ISP & thrust to weight ratios.  He was asked about testing & we learned they plan on doing ground tests at the Nevada Test Site.  Listen to why their tests will be different from earlier nuclear rocket engine tests & how they are expelling the exhaust into the ground.  You will hear There is no radiation, only hydrogen which bleeds into the rock strata.  We also talked about public concern for nuclear power in space, then we shifted our focus to a nuclear rocket mission to Mars.  Dr. Howe told us about the three year Mars mission but also said with a nuclear rocket a one year mission would be possible.  We also talked about the costs for developing the nuclear rocket as well as the possibility of other countries doing it before the U.S.  Next, we talked about the use of uranium & even the possibility of thorium, including why thorium is not useful for weapons. One listener question asked about the Mars Direct method & insitu resource utilization.  Dr. Howe supported the use of insitu but suggested it for later trips as it might be too risky for the initial trips.  He then described their Mars Hopper project which will certainly interest us all.  As this segment ended, we talked about using the nuclear rocket for going to the Moon & for a lunar & even Martian habitat. 

As we started our second segment, Dr. Howe was asked if QuickLaunch could be useful.  Dr. Dewar sent in a clarification note about U-233 as a byproduct of  thorium & why its a problem for weapons.  In talking about a lunar habitat, Dr. Howe told us about the NASA Fission Surface Power Program (FSP).  We also talked about using the new tungsten fuel for habitats.  He told us about the Nuclear Thermal Mars Sample Mission Study that compared the nuclear rocket to Delta IV launches.  Listeners asked about Vasimr & our guest was asked to clarify for us the differences between nuclear electric propulsion & nuclear thermal propulsion & why the latter is preferable.  Dr. Dewar sent in another note to talk about Y-12.  Later, much was said about plutonium & its pending shortage.  Make sure you hear what Dr. Howe had to say about this looming shortage. Near the end, Dr. Howe mentioned his efforts with Hbar Technologies, LLC, suggesting that possibly using these nuclear advancements for medicine, specifically cancer, might be a driver for space applications. As we concluded, Dr. Howe told us about his books on Kindle & the consolidated all in one book, “Earth Rise.”  Here is the Amazon URL & remember, if you buy it using this URL, Amazon contributes to The Space Show: www.amazon.com/Earth-Rise-ebook/dp/B005LD3LYS/ref=onegialeafou-20

Post your comments/questions on the blog URL above.