Broadcast 2965 Dr. Franklin Chang Diaz, Dr. Erik Seedhouse

  • The Space Foundation Conference

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  • The Space Foundation Conference

The Space Foundation Conference

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Guests:  Dr. Franklin Chang Diaz, Dr. Erik Seedhouse;  Topics: Erik's new book, "To Mars And Beyond, Fast!", plasma propulsion, VASIMR, advanced propulsion, and lots more.  Please direct all comments and questions regarding specific Space Show programs & guest(s) to the Space Show blog which is part of archived program on our website,  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

We welcomed Dr. Franklin Chang Diaz to the show for the first time along with Dr. Erik Seedhouse regarding Erik's latest book, "To Mars And Beyond, Fast!".  This book documents and details the work by Dr. Diaz on the plasma propulsion system referred to as VASIMR by the Ad Astra Rocket Company.  The book, authored by both Dr. Diaz and Dr. Seedhouse, is an absolute must for understanding the history, present status and future potential for this exciting technology.  Remember, if you buy the book, and I strongly urge you to do so, make sure if you use Amazon to use the Space Show/OGLF portal so that Amazon will donate a portion of your purchase price to the show.  Click on the large Amazon link on our home page (center) for instructions or email me if you have questions.

During our 60 minute one segment program, Dr. Seedhouse introduced us to his book, the subject, and why he wanted to research and write about VASIMR which he said several times during our program :"was the way of the future."  Erik then passed the microphone to Dr. Diaz and we spent most of the rest of our time discussing plasma propulsion and VASIMR in detail along with listener questions and a phone call.

Dr. Diaz started by giving us a short introduction and history for plasma propulsion, the type of fuel it would use which was essentially any type of gas, comments about the 3-5 million degree temperatures for the exhaust gas, the magnetic nozzle and electromagnetic containment.  He said they had a working engine with test firings at 200 kw and were working toward the NASA requirement for a 100 hour continuous test at 100kw to be conducted later in  2018.  Once the 100 hour test has been successfully concluded, they will be ready for an in space test at the ISS.  Dr. Diaz explained this process and the timing in detail so don't miss it.

Franklin also talked about the fuel saying any gas would work.  He said with the heavier gasses, you get more thrust but less efficiency.  For their tests they have been using argon but they could get significantly more energy using hydrogen.

Franklin talked about locating VASIMR at an Earth-Moon LaGrange point with cargo being brought to it via a chemical rocket. Later in the discussion he said they would be open to talking with all chemical rocket companies but that they were not ready for that at this time.  Our guest further said that for going to Mars or someplace closer, they could use SEP (solar electric power) but that were they to go much beyond Mars, they would need nuclear electric propulsion.  In fact, he said nuclear electric power was essential for Mars and beyond and human spaceflight.  Ad Astra Rocket Company would not be building the nuclear electric propulsion systems, others would have to do that. We talked about roadblocks to nuclear electric propulsion, fear, and other issues.  This is a potential bottleneck but our guest said other nations might develop it if we don't.  The subject of SEP and nuclear electric propulsion came up several times during our discussion so don't miss the additional comments.

I asked Franklin about a potential interstellar application for VASIMR.  Don't miss his reply which was largely focused on imagination laced with present day reality checks.  He mentioned the long term possibility of seeing things morph into using a thermo nuclear powered rocket but stressed this was very futuristic. 

The subject of mass to Mars was discussed. Franklin cited the equation of kilos over KW.  He showed the changes using nuclear electric power.  Make sure you listen to what he said about this.  Don't miss it.

George asked him about Ad Astra funding.  You do not want to miss  this short discussion because the funding history reflects VASIMR progress.  His response included a discussion of the current three year NASA contract for $9.1 million.

I asked both Erik and Franklin for the current TRL for VASIMR and what TRL was needed for commercial operation.  Erik explained that there was lots of competition for dollars with other systems.  Hall thrusters was one such system mentioned.  Franklin said the current TRL was about 5.  At the end of the upcoming 100 hour test the TRL would be 6.  After that, he said the technology would advance faster but the costs would go up.  Don't miss this TRL discussion.

Listener Adrian sent in the following question:  "This question is for Dr. Diaz. In the 2014 proposal for a VASIMIR  Europa mission paper the point is made that for use of hydrogen as a ion source the helicon frequency would require a modification to a 240 megahertz RF unit that could double as a probe radar system. Would the ICH frequency also need to be adjusted to compensate for the correct ion cyclotron resonance frequency? So would each VASIMIR engine utilizing other ion sources such as krypton or argon need to be customized for each fuel?"  Franklin provided Adrian with a thorough answer so don't miss it.

I asked Franklin what I would see if I were looking at VASIMR during the 100 hour test.  Franklin described the test, the very large vacuum chamber which he said was about 4M X 10M.  He told us what we would see were we looking through the porthole during the test.  Also, what we would hear. 

Terry from Texas gave us a call talking about fuel, the reference mission and the lunar location.  Richard sent in a note asking about SEP, cislunar logistics and commercial usage.  The subject of chemical rocket transport to VASIMR on station was discussed. 

A listener as well as myself asked Franklin about the exhaust heat and he explained the heat was the kinetic energy coming out the rear of the rocket making the rocket move forward.  Don't miss his explanation and discussion.  He also talked about VASIMR specific impulse.

Adrian sent in another note wondering if VASIMR had a commercial potential for cleaning up orbital debris.  Franklin said yes and talked briefly about their "sweeper" plans.  There were a few additional comments before we ended our program.  Erik concluded saying that VASIMR was the way of the future.  Franklin talked about this being a huge human endeavor for the entire planet.  Don't miss his ending remarks.

Please post your comments/questions on TSS blog for this show.  Check out the Ad Astra Rocket Company website for the latest in VASIMR news, videos, and information  (  You can reach Franklin or Erik through me or their websites.  Again, a very special thanks to Monica in the Ad Astra office for helping to arrange this program.  Her efforts, friendliness, and skill were fabulous!




Erik's new book, "To Mars & Beyond, FAST!, plasa propulsion, VASIMR

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14 Aug 2017 Dr. Franklin Chang Diaz, Dr. Erik Seedhouse
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