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

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

http://archived.thespaceshow.com/shows/1711-BWB-2012-02-12.mp3

NUCLEAR THERMAL ROCKETS

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

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

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

http://archived.thespaceshow.com/shows/1697-BWB-2012-01-24.mp3

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.

Nicholas (Nick) Johnson, Monday, 12-5-11 December 6, 2011

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Nicholas (Nick) Johnson, Monday, 12-5-11

http://archived.thespaceshow.com/shows/1666-BWB-2011-12-05.mp3

 

Nicholas (Nick) Johnson. Topics:  Space debris issues.  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.  The Space Show/OGLF is now engaged in its annual fundraising drive. Please see & act upon our appeal at https://thespaceshow.wordpress.com/2011/11/21/space-show-2011-fundraising-campaign.  We welcomed Nick Johnson back to the show for a comprehensive discussion on space debris issues.  We started out with an assessment of the space debris problem as of today.  Here, Mr. Johnson talked with us about the impact of sun on space debris through both the solar max and the solar minimum.  I referenced the NRC report and asked if concurred that we were at the “tipping” point in the debris issue.  We talked about cleaning up debris and our guest said that various options were being looked at but we were not there yet.  Nick mentioned a few possible technologies but that funding was needed, demo projects needed to be carried out, and that international cooperation and funding consortium ideas were being explored.  Space attorney Robert called in regarding some of the legal issue needing to be addressed based on the Outer Space Treaty, the Liability Treaty and other legal documents.  Perhaps the biggest legal issue is that of needing permission from the owner of the hardware to retrieve or do something with it so that it does not add to the debris problem.  We did talk about mitigation strategies for newer satellites and I inquired why the 25 year boundary for keeping the satellite from becoming debris.  Jerry called in and wanted to know about the possibility of magnetic cleansing and suggested VASMIR.  Another listener asked about satellite upset events that happen when a satellite gets hit with really small flakes of debris causing the satellite to reboot.  Before the break, we talked about the return to Earth of the Upper Atmosphere Research Satellite (UARS) and Nick talked about tracking the return of objects.  Don’t miss this discussion.  I also asked him about Burnt Frost, the U.S. satellite shoot down in 2008.  We started the second segment with a listener question about possible titanium tanks on Phobos-Grunt and reentry concerns.  Nick said that Russia said the main tanks were aluminum and that Russia should be addressing reentry concerns.  We talked in general about the problem of hydrazine and it remaining frozen during reentry.  Another listener asked about plutonium on board spacecraft and the Russian accident in Canada with Cosmos 954.  Another listener asked about cubesat and possible debris issues.  Space tugs for debris removal were discussed as were Earth-based lasers.  International cooperation was discussed and of course ITAR came up.  As the program was ending, we talked about NASA’s reentry plans for both the ISS and the Hubble Space Telescope.  Nick also clarified the law for us regarding keeping pieces of satellites or debris that hit the Earth as they remain the property of the launching country.  Please post your comments/questions on The Space Show blog URL above.