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Dr. Doug Plata, Sunday, 3-16-14 March 17, 2014

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Dr. Doug Plata, Sunday, 3-16-14

http://archived.thespaceshow.com/shows/2208-BWB-2014-03-16.mp3

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Guest:  Dr. Doug Plata.  Topics:  Selected trades for the Cis-Lunar One Transportation Architecture as developed by Dr. Plata.  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. 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 back Dr. Doug Plata to the show to discuss his selected trades for his Cis-Lunar One Transportation Architecture.  You can find Doug’s Choices of Selected Trades document on The Space Show blog at https://thespaceshow.wordpress.com under the summary for this particular program and date.  In the first segment of our 2 hour 6 minute discussion, Dr. Plata started out giving us an overview of his project, mostly by reading to us the “Overview of the Cis-lunar One Architecture” which is part of his document on our blog.  In addition, Dr. Plata wants your feedback regarding his project, including constructive criticism.  You can email Dr. Plata at dougspace007@gmail.com.  After discussing the project overview with us, Doug started addressing the trades listed in his document.  We started with Trade 1 Launcher.  Doug went through all of his considerations for launchers, was clear that he was not ruling any particular rocket out of the question.  Make sure you note his “Table1: Choice of Launcher & Fuel.”  The led us to discussing payload issues for the mission.  Also note that Doug has named his lunar craft the Condor upper state LL as you will see that name show up throughout our discussion.  Doug then went to Trade #2 and discussed propellant choices.  Note his Table showing the specifics of his Choice of Fuels assuming 53 tons at LEO and a 15% dry mass.  He received several listener questions, including questions about where to on the Moon.  See Trade 8 Initial Landing Sites for his choices and reasoning.  We skipped to Trade 12 Power in Shadows.  He discussed power options in some detail and went through the four options listed in this trade.  Mary Beth sent in some questions asking Doug about his propulsion discussion and Marshall called in with a series of questions about ice and the regolith.  Doug then took us to Trade 17 Repairs.

In our second segment, Doug started with Trade 17 repairs, focusing on redundancy, spare parts, & surface equipment easy designs.  Later in the segment, Dr. Plata was asked about lunar dust and maintenance/problems for the equipment.  A listener emailed him about market possibilities, our guest fielded other listener email questions and then Doug addressed Trade 9 Landed Configurations including belly landings and tail landings. Trade 14 Surface Equipment was discussed, then John called in to talk about a needed detailed lunar surface survey.  I asked our guest for his detailed cost projections for his mission followed by his next step in promoting his architecture.  He talked about having called his Congressman, Representative Mark Takano.

Please post comments/questions/feedback on TSS blog per above.  You can also email Dr. Plata at his above email address, plus its on his trade document which is on TSS blog.

Comments»

1. James Fincannon - April 30, 2014

Dear Dr. Plata,

I listened with interest to your explanation of your lunar
architecture on the Space Show. I have a few comments.

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20080008842.pdf is a good paper for the various power transfer modes on the surface. Separately, I had looked into using mirrors to beam sunlight onto solar arrays in a crater, which might work. http://www.cnn.com/2013/11/01/travel/rjukan-sun-mirror/. But power cables do seem easier.

Regarding the “Peaks of Eternal Light” you wish to land at, the current data shows there are no such locations. Even Spudis states this in http://www.airspacemag.com/daily-planet/new-light-on-the-lunar-poles-156800678/ . More recent analysis of LRO data show no such locations too. The paper entitled “Persistently illuminated regions at the lunar poles: Ideal sites for future exploration” in Icarus, Volume 222, Issue 1, January 2013 http://www.sciencedirect.com/science/article/pii/S0019103512004174 used LRO WAC and NAC images and did not find any such spots within 2 deg of the poles. But, I do not think their data very useful for a number of reasons we needn’t go into here. The TRUE data source to determine lunar polar illumination is the LOLA (laser bounce data) altimetry. Both LRO and Kaguya did this. Kaguya (“Illumination conditions at the lunar polar regions by KAGUYA(SELENE) laser altimeter”, Geophysical Research Letters, Volume 35, Issue 24,December 2008 http://onlinelibrary.wiley.com/doi/10.1029/2008GL035692/pdf ) reported that no 100% illumination areas were found. But the best source of data is from LRO ( “Illumination conditions of the lunar polar regions using LOLA topography”, Icarus, Volume 211, Issue 2, February 2011). The best he could find was 86.6% illuminated with a solar array starting at 30 feet above the lunar surface at the north pole. What all this means is that you will need batteries to survive, because although you can go into dormancy, if the duration is a day or two, you need to provide heat to the hardware in the crater and on the rim to keep from freezing solid (especially the joints and electronics).

Regarding use of lunar materials for ion thrusters: magnesium works and is available in lunar regolith (6% in the form of MgO). Szabo, J., Robin, M., Duggan, J., Hofer, R., “Light Metal Propellant Hall Thrusters,” 31st International Electric Propulsion Conference, IEPC Paper 09-138, University of Michigan, Ann Arbor, Michigan, September 20 – 24, 2009. http://richard.hofer.com/pdf/iepc-2009-138.pdf
Szabo, J., Robin, M., Paintal, Pote, B., S., Hruby, V., “High Density
Hall Thruster Propellant Investigations,” 48th AIAA/ASME/SAE/ASEE
Joint Propulsion Conference, AIAA Paper 2012-3853, July 2012.
http://arc.aiaa.org/doi/pdf/10.2514/6.2012-3853

Regards,
James

DougSpace - May 1, 2014

Hi James,

Thank you for your thoughtful response. I found your NASA profile and so appreciate someone who works in the field considering my proposed Cis-lunar One concept.

Yes, I have been aware that the so-called “Peaks of Eternal Light” are more of an historic term rather than technically correct. My future documents will use the term “Peaks of Persistent Illumination” instead although, as a physician, PPIs are normally what we use to manage stomach acid.🙂

None-the-less, Dr. Spudis and others point out that you can connect these peaks with wires and hence get coverage approaching 100%. Whereas I think this is a likely scenario later on, the initial emphasis of the Cis-lunar One concept is to establish basic operations and to harvest enough volatiles ASAP in order to initiate cis-lunar operations first to LLO followed shortly by EML1 and then LEO operations.

My sense is that the risk of operations being suspended due to mechanical breakdown due to harvesting is greater than suspension due to the failure of a battery system to keep equipment warm during a partial lunar night. However, power-intensive operations would have to cease until the solar panels at the peak came into the sunlight again. So I suspect that it would be better for the second launch to have spare parts and redundant equipment rather than more solar panels and wire. But, if harvesting operations go well then I could imagine the third launch delivering more solar panels to another peak and the connecting wire in order to get closer to continuous electricity production.

I would like to point out that another solution besides batteries would be to burn a bit of the (initially reserve and later produced) propellant by using a fuel cell. So there are some interesting options.

I too thought about using mirrors. I have seen stretched reflective Mylar which works very well yet is low mass. But I do have a concern about missing the receiving solar panels at the worksite down in the shadowed crater and hence warming our precious source of volatiles. Like you, I think that draping a wire down the side of the crater during the initial hop is easy enough that I think it stands out as the best trade.

Regarding magnesium as an ion propellant, thanks for that info as well. I think that including ion propulsion within the cis-lunar transportation system could be a real advantage. A quick look showed that lunar scientists have found an area of magnesium spinel which is about 17% by mass of magnesium. In the end, economics would determine where we would get our source of ion propellant.

If you’re willing, I’d like to communicate with you a bit more about the energy requirements of a lunar surface operation. My address is: FirstLast at gmail. Thanks.

J Fincannon - April 24, 2015

“None-the-less, Dr. Spudis and others point out that you can connect these peaks with wires and hence get coverage approaching 100%. ”

Bussey using Kaguya LIDAR (2010) data show 94%, not “approaching 100%”. The old Clementine data suggested 98% (1998), but that was somewhat flawed (not worse case, deep Winter, of the year, etc).

2. Patrick - March 26, 2014

Interesting show and paper. But I believe there is one major thing missing from the paper: there are no references listed for the claims made!

It looks like you’ve done a lot of research, but without knowing the sources it’s near impossible to dig deeper and validate the base assumptions.

For example you talked about making methane on the moon using Carbon Monoxide. What chemical process are you proposing? How much energy does it take? How much carbon monoxide is there suspected to be on the moon and how would it be harvested?

3. DougSpace - March 21, 2014

Hi Jim,

In the Cis-lunar One scenario, supportive transfer infrastructure on the surface would definitely be in place. Previously landed Condor landers would be fully fuelled. So if people became stranded anywhere in cis-lunar space or at a distant lunar location then a robotic lander could be launched to their location with enough propellant to either take them to the lunar base or as far back as Earth. I am not too concerned about fuel margins for manned landings. I would rather the manned landers be fuelled with more than enough fuel to allow abort to LLO or even to Earth. Regarding a “soft crash” are you thinking about, in an emergency, the crew pod detaching from the fuel & LOX tanks? Interesting possibilities. I could imagine that the computer would automatically handle the different abort modes.

DougSpace - March 21, 2014

I mean…Joe !

4. Joe from Houston - March 20, 2014

I mentioned concerns about fuel margins for aborted lunar landings back to orbit and back to Earth like they had during Apollo. A colleague recommended having a way to abort to the lunar surface. That uses way less fuel than going into lunar orbit. It gets the crew out of harms way until they can return to lunar orbit in a fully fueled surface to orbit transfer vehicle. The difference being a supportive transfer infrastructure on the surface versus none during Apollo. A soft crash landing is also an option with a crew cabin filled with nitrogen and the crew being in their space suits would not catch fire or explode on impact. At 1/6th Earth gravity, the soft impact would be a lot softer.

5. Jim Davis - March 19, 2014

This was a good show. I have two comments, somewhat related.

I think it would be a good idea if Dr. Plata would state what level of beyond LEO activity would justify his cislunar development scheme. A statement like “This project will break even when mass beyond LEO rises to x times the current level” or something similar.

I was disturbed by Plata’s retreat to the “If you believe we’re never going back to the moon then of course my scheme makes no sense” position. Space advocacy will be much better served if it could dispense with these emotional appeals. The current COTS program made sense because we had a space station in orbit and we needed a cheaper means to access it. A lunar COTS program only makes sense if there are actual plans for a large increase in beyond LEO activity. Plata wants NASA to act as an anchor tenant for his scheme. This presupposes that there is going to be a large increase in NASA missions to beyond LEO. This does not seem to be realistic given the NASA budget. Plata did not deal with this issue in any substantive way other than muttering “Have faith, have faith.”

I like Plata and I can think of a lot worse ways to spend the NASA budget and I would not at all be distressed if his scheme got funded. But I can’t help but think that this project is another “build it and they will come” effort with words like “public/private partnership” and “lunar COTS” as sugar coating to help a bitter pill go down.

6. Space-for-All at HobbySpace » Space policy roundup – March.17.14 - March 17, 2014

[…] Dr. Doug Plata, Sunday, 3-16-14 – Thespaceshow’s Blog – A discussion of the  Cis-Lunar One Transportation Architecture developed by Dr. Plata. (Find background docs here.) […]


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