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Dr. Jason Cassibry, Friday, 12-20-13 December 21, 2013

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Dr. Jason Cassibry, Friday, 12-20-13

http://archived.thespaceshow.com/shows/2147-BWB-2013-12-20.mp3

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Guest:  Dr. Jason Cassibry.   Topics:  Nuclear propulsion including fission, fusion, reactors in space and more.  Please direct all comments and questions regarding Space Show programs/guest(s) to the Space Show blog, http://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.

We welcomed back to the show Dr. Jason Cassibry from the University of Alabama Huntsville to discuss nuclear propulsion of all kinds.  In our initial segment of this 1 hour 30 minute discussion, I first asked Dr. Cassibry about a fusion drive project as reported at www.youtube.com/watch?v=r-jlv1x3ov4.  Dr. Cassibry spoke about the work going on at the University of Washington which was mentioned in the fusion drive video above.  We then talked about transit times to and from Mars and the differences with chemical propulsion, nuclear thermal, and then fusion.  During this discussion, Jason also described the differences in nuclear thermal and nuclear electric propulsion.  A related issue we discussed dealt with the nuclear regulatory environment.  We talked about the nuclear climate, protests, and how best to overcome such protests.  Doug called asking about timelines and said it was moving at such a slow pace, for his projects that he thinks about, he dismisses nuclear propulsion, instead opting for analysis and mission planning using chemical rockets though many are not much further along than a Power Point at this point in time.  Doug also thought it might be easier to do nuclear propulsion by partnering with Russia as they might be easier on the regulatory environment than the U.S.  Our caller asked about ion propulsion and thrusters as well as thermal protection needs.

In the second segment, Jerry emailed about nuclear propulsion in other countries plus more about possible consumer protests.  Ben asked if we could substantially improve chemical rockets and I inquired as to why the recent nuclear program Prometheus was killed.  VASIMIR was next brought up for discussion.  I asked Jason about nuclear accidents in space or on Mars and would they be as destructive as nuclear reactor accidents here on Earth.  Jason provided a most interesting answer saying he thought nuclear reactors in space would be accident proof!  Christine in Dallas suggested we need a better story for more support for nuclear propulsion.  Don’t miss the reply offered by Dr. Cassibry. Near the end of our discussion, I asked our guest about suborbital propulsion.

Please post your comments/questions on TSS blog above.  You can email our guest through me.

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

http://archived.thespaceshow.com/shows/1915-BWB-2012-12-16.mp3

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, http://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. Jason Cassibry, Tuesday, 10-9-12 October 10, 2012

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Dr. Jason Cassibry, Tuesday, 10-9-12

http://archived.thespaceshow.com/shows/1869-BWB-2012-10-09.mp3

Guest:  Dr. Jason Cassibry.  Topics:  A technical description and the potential of fusion propulsion.  You are invited to comment, ask questions, and discuss the Space Show program/guest(s) on the Space Show blog, http://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. Jason Cassibry to the program to guide us in our discussion of the potential for fusion propulsion.  At times, this was a very technical discussion.  To assist in following it, I have uploaded to the blog his published paper delivered at the AIAA Joint Propulsion Conference, “The Case and Development Path for Fusion Propulsion.”  In addition, below are the URLs for several articles on fusion propulsion that Dr. Cassibry shared with us: www.uah.edu/news/items/10-research/2501-slapshot-to-deep-space#.UDrKn-iPVuY;
www.popularmechanics.com/science/space/rockets/the-big-machine-that-could-lead-to-fusion-powered-spaceships-9450996; http://io9.com/5921673/nuclear-slapshots-could-propel-a-spacecraft-to-mars-in-just-weeks; www.centauri-dreams.org/?p=23442
and http://nextbigfuture.com/2012/10/zpinch-nuclear-fusion-pulse-space.html.   Dr. Cassibry started out by providing us with a working definition of fusion propulsion.  We talked about nuclear propulsion as well and the overall state of development for fusion energy.  I asked Dr. Cassibry if in their economic projections for fusion propulsion, they considered the political and policy impact on fossil fuel pricing and supply availability.  As you will hear, generally such factors are not included in their studies though he concurred with me that such policies can strongly skew the economics one way or the other.  Several calls came in on a wide ranging group of associated topics.  We talked about the main fusion fuel, lithium deuteride, magnetic nozzles, and the use of a nuclear fission reactor to start the fusion propulsion unit.  Z-Pinch technologies were defined and discussed.  As the segment drew to a close, I asked about funding sources for this research and we learned that most all of the funding is from public sources.

In our second segment, more listeners called in regarding insitu resource usage, nuclear propulsion to start the fusion unit, and the power consumed for all of this.  We talked about using fusion propulsion for a Mars mission and what it did for travel times.  Jason also put forth a suggested time line and path to follow to operation in perhaps 25 years, depending on funding.  More calls came in with fuel questions, vibration impact, G force acceleration, thrust, and more.  Another topic discussed was fusion propulsion for the launch vehicle.  We then compared some real mission travel times such as Cassini, Voyager, and New Horizons, asking what the transit times would have been like using fusion propulsion.  As we were ending the program, I asked about the students entering aerospace engineering at UAH, both the undergrad and graduate level, plus the gender mix of the students.  There appears to be strong demand by the students to study these fields at all levels.  In conclusion, Jason suggested that we could look for breakeven with fusion in about ten years, maybe less.

If you have comments/questions, please post them on The Space Show blog.  Dr. Cassibry’s faculty page at UAH is www.mae.uah.edu/faculty/cassibry.shtml.

 

Cassibry et al case for fusion 072812

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