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Don Nelson, Tuesday, 11-3-15 November 4, 2015

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Don Nelson, Tuesday, 11-3-15

http://archived.thespaceshow.com/shows/2578-BWB-2015-11-03.mp3

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Guest: Don Nelson.  Topic:  Development of a fleet of privately operated Commercial Space Shuttle Freighters (CSS Freighter) for commercial space, NASA & Air Force.  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 Don Nelson back to the show for this 90 minute discussion regarding his Commercial Space Shuttle Freighter (CSS Freighter) concept.  During the first segment, Don provided us with an overview of our current launch and human spaceflight situation, he talked about safety and reliability, then he started describing his CSS Freighter Concept.  You can learn more about it at his website, www.spacetran21.org.  He spent time explaining why wings were needed despite the common misconception that they become worthless mass in space.  He said over and over again that if one does the trades, wings come out far better than carrying additional propellant for a vertical landing.  He also said he was a strong proponent of full reusability, not just first stage reusability.  In response to several questions, he said his CSS Freighter was modeled after the shuttle but with new upgrade designs and technology though to save money and reduce development time, the freighters were to be based on existing technology.  He had much to say about the difficulty they had in upgrading space shuttle systems so this time around he said upgrades would be modular and as close to plug and play as possible.  His idea is that the freighters will be built and operated by the private sector.  He suggested the extensive use of composite materials to save on mass and to use reusable Space Shuttle Main Engines (SMEs).  He referenced the Air Force X-37B program, he talked about the advance state of the thermal protection systems (TPS) for this top secret spacecraft suggesting it would be the TPS of choice for the freighters.  Our guest was challenged in both segments regarding other reusability options including the advancement toward success represented by SpaceX and the Falcon 9.  Don said it was first stage only, he was talking about full vehicle reusability and making the case for his approach with wings.  Don’t miss the challenges and the replies. Don also spelled out the advantages of horizontal as compared to vertical vehicle landing regarding reusability.

In the second segment, BJohn asked about the Soviet version of the shuttle, the Buran.  Don mostly talked about lessons learned by their not having a reusable space shuttle main engine (SME).  Don was asked about international vehicle participation in his freighter project. He said not with this Congress and referenced our policy on not talking with China.  Don was also asked for the rational for doing this and he focused on competition.  Make sure you hear this discussion.  He said he was including the Air Force in his plan given the rapid turnaround time for the vehicle (five days).  He explained the Air Force market in detail and is in touch with key Air Force people.  In addition, he has made presentations to members of Congress and their staffs plus key people at NASA.  I asked him how they responded to the concept.  You don’t want to miss what he said about that.  Alex asked an email question about launch pads and NASA having altered or gotten rid of the shuttle launch pads.  Don said launch pads were not an issue, even suggested foreign launch sites, but did say KSC was a prime launch location in the U.S.  Don attacked expendable rockets over and over again in both segments so Ben from Seattle pressed him as to why his reusable freighter would be more reliable than an expendable rocket.  He said each flight of an expendable rocket was a test flight.  Our guest received a questions about suborbital flight evolving to orbital flight, listeners asked about private Bigelow space stations, and one listener wanted his thoughts on the Skylon.  Tim called in and talked about chemical rockets and rocket fuel. He also inquired about scramjets and Big Dumb Boosters.  Doug called in to challenge his reusability comments citing the Falcon 9 to make his case that wings were wasted mass.  Don’t miss this discussion.  When asked if he thought things would change as a result of the coming elections, he suggested that a new congress would likely terminate SLS given our budget & SLS problems.  Don’t miss the balance of his concluding comments.

Please post your comments/questions on TSS blog above.  You can reach Don Nelson through me or his website.

Space Show Webinar with Dr. Haym Benaroya, Dr. John Jurist, Sunday, 2-17-13 February 14, 2013

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Space Show Webinar with Dr. Haym Benaroya, Dr. John Jurist, Sunday, 2-17-13

Behind The Scenes Engineering for Space Structures and Infrastructure

http://archived.thespaceshow.com/shows/1951-BWB-2013-02-17.mp3 (audio only)

http://vimeo.com/channels/thespaceshow  — Video

Guests:  Dr. Haym Benaroya, Dr. John Jurist.  Topics:  Engineering space structures, hardware, and habits for LEO, the Moon, and Mars.  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 our main guest Dr. Haym Benaroya and co-host Dr. John Jurist to our first Space Show webinar for 2013.  As Dr. Benaroya is a mechanical and aerospace engineering at Rutgers University and well known for lunar architecture and engineering structures, we asked Dr. Benaroya to take us behind the scenes for a look into the engineering needed to have something in LEO, on the surface of the Moon, or Mars.  Dr. Benaroya prepared a special .pdf presentation for us which is on The Space Show blog per above.  I urge you to follow along with the .pdf slides as Dr. Benaroya discusses space engineering.

     During the first half of this two hour five minute webinar, Dr. Benaroya started out by discussing some of the basic issues in space engineering including gravity.  He started with Slide 2 and talked about each item and the engineering considerations associated with it, both here on Earth and in space.  As you will hear, not only are the engineering considerations significantly different between Earth and space, but many are also different from one another depending on if the project is in LEO, on the Moon or Mars.  Make sure you follow along with him using his slides.  Listeners, Dr. Jurist, and I asked Professor Benaroya many questions about lunar based habitats, LEO habitats, shapes, pressure forces, regolith issues, heat issues, and more.  Referring to Slide 5 Dr. Benaroya talked about gravity issues and concerns.  Slide 6 was about lunar dust issues, tidal forces, seismic concerns.  We compared seismic reinforcing in San Francisco or other terrestrial earthquake zones to what would be needed on the Moon.  The subject of engineering for extreme and rapid temperature changes came up for LEO, the Moon & Mars.  Dr. Benaroya suggested many times during our discussion that we would need to use ISRU given the high cost of getting materials to space.

     In this first segment, other topics included the potential afforded lunar engineers by having a Lunar Space Elevator available and even a lunar bulldozer!  The subject of heavy lift came up as it always does on these programs and all of us talked about fewer larger launches as compared to many smaller launches, even using depots. Doug called in to argue for the Falcon Heavy.  As Dr. Jurist pointed out, putting mass on the Moon is about 10% give or take of the rockets IMLEO mass capability.  In responding to Doug, both Dr. Jurist & Dr. Benaroya illustrated the difference between the Falcon Heavy and SLS regarding landing a specific mass on the Moon.  Just before the segment ended, in responding to a question from Dr. Jurist, Professor Benaroya suggested that each person on the Moon would need about 20 times his or her weight in mass on the lunar surface for around a six month stay.  To determine the most cost effective way to get the needed infrastructure and mass safely to the lunar surface, lots of issues go into the trade studies to determine the best approach, including launch vehicle choice.

     In the second segment of our webinar, we took a call from John in Florida who wanted to ask Dr. Benaroya about his earlier comment about using magnesium on the Moon as a type of rebar in lunar concrete.  We next talked about reliability, power sources, competing technologies and design issues.  One of the issues brought up was the need to design the structure to be successful during the design phase, not just the completion stage. This was a most interesting discussion, don’t miss it.  One of the points he made was that we can’t test structures in space like we can on Earth so engineering design issues must be considered & dealt with for space that would not be encountered on Earth.  He talked about the preferred shape for a lunar structure and advocated the arch as in Slide 21.  Our professor then talked about design standards here on Earth, the fact that we have none for space so all of the Earth standards are extrapolated to work in space though we have no history for doing this. Also, he talked about using four to five times for a safety factor where on Earth the safety factor might be more like 1.5 or 1.6.  We also talked about confidence intervals. While on Earth, something may be done with a CI of 95% or higher, he suggested that on the Moon or in space the CI would more likely be pretty low, around 70 or maybe 80%!  He cited dust design as an example of what he was talking about as dust is not a big factor in terrestrial engineering but it will be on the Moon or Mars.  Doug called again to advocate inflatable structures rather than the engineering and building of structures.  Prof. Benaroya suggested that they may be used early on but that most of the studies show their primary advantage to be in transportation because on the surface they have to be made rigid.  This is another discussion you don’t want to miss.  Near the end of our webinar, advanced manufacturing for the future was discussed.  Dr. Benaroya talked about advances in robots, layered manufacturing and 3D printing. He explained how these can really change the game for space structures, engineering, manufacturing, and costs.  Near the end, questions came in as to why the Moon instead of Mars, the 7-8 year time lines mentioned by the lunar companies and Mars One as well as wanting to know if space engineering was strictly an academic project or if it was being worked real time by companies that can actually make hardware.  As you will hear, it’s a combination of both at this time.  Dr. Benaroya kept talking about time lines 2-3 decades long and I asked him about speeding that up and the short time lines for the lunar and Mars One group.  He did not think the shorter time lines were feasible.  See what you think after you hear his and Dr. Jurist’s comments on emerging company time lines.  Dr.  Benaroya concluded by pointing out the popularity of these subjects in both undergraduate and graduate classes and the importance of student research and its benefits.

     Please post your comments/questions on The Space Show blog above.  To email Dr. Jurist, do so through me at drspace@thespaceshow.com.  You can contact Dr. Benaroya at benaroya@rci.rutgers.edu.

Here is Professor Benaroya’s webinar presentation material:

Space Show Prof. Benaroya Webinar Lunar Structures Engineering 2-17-13

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