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Dr. Bruce Damer, Friday, 6-12-15 June 12, 2015

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Dr. Bruce Damer, Friday, 6-12-15


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Guest:  Dr. Bruce Damer.  Topics:  Sustainable space exploration to Mars & elsewhere per his two TEDxSantaCruz talks.  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 Dr. Bruce Damer back to the show to discuss his two new TEDxSantaCruz talks regarding sustainable space exploration and new theories on the origins of life.  Watch the first of his two TEDx talks on sustainable space exploration at www.youtube.com/watch?v=wLMHcUg36yc.  His second TEDx talk addressing new theories on the origins of life can be viewed at www.youtube.com/watch?v=6qiW4aUqtvA.  In the first segment of our 1 hour 28 minute discussion, Dr. Damer introduced us to his concept for sustainable space exploration, including round trips to Mars.  His spacecraft is the S.H.E.P.E.R.D   which he fully explained with great animation in the TEDx talk.  This is a method for capturing and enclosing a small but valuable asteroid between Mars and Jupiter, using a chemical process to mine it for volatiles and to fill special tanks with the volatiles and return the cargo to where it is needed, Mars, the moons of Mars, cislunar space, the Moon, or an orbiting space station.  Bruce spent the first segment of our program discussing this technology and the concept, plus explaining how it can be used to facilitate and enhance human spaceflight including human exploration of the solar system.  The YouTube video is just under 10 minutes so be sure to watch it.  Listeners asked him many questions to fully understand the concept so the YouTube talk and his Space Show discussion go hand in hand with one another.


In the second segment, Bruce as asked about the cost to develop, launch, and operate S.H.E.P.E.R.D for a humans to Mars mission.  Bruce did not have costs available but used the Rosetta Mission as an approximate guideline for estimating costs. Also in this segment, he noted the use of inflatables in space and the long history of success in using them back to the early days of the space age and the Echo communication satellites.  He also referenced Genesis 1 and Genesis 2 on orbit through Bigelow Aerospace.  He then said that inflatables would be safer for humans due to less radiation.  Don’t miss his comment on this issue.  Bruce then talked about water and shielding.  As the program was nearing its end, Dr. Damer discussed the second TEDx talk regarding new theories on the origins of life.  He also connected the dots for us with both talks so don’t miss what he had to say. By the way, the sustainable space exploration talk opened the TEDx session and his origins of life talk was the closing talk at the event.  Toward the end, he talked about outreach with his new idea and said he would be giving a FISO talk on S.H.E.P.E.R.D June 24 so those of you who listen to FISO talks be sure to catch this one live or on archives.  Before the show ended, Bill emailed in a question asking him if he had a compelling rational for Martian HSF.  Don’t miss what he said about this.  A Phoenix listener asked Dr. Damer if his concept would help Mars One.  Then a series of questions came in asking Bruce about the use of his idea for going to the Moon, cislunar development, the moons of Mars or someplace else in the solar system.  Bruce said it would support all of these missions and explained why.  Jim asked Bruce to explain why he thought mining an asteroid would be so difficult and far out yet he was mining volatiles from the asteroids he covers up with his plan.  Bruce explained that he was using a chemical process to free up the volatiles, not mining them.


Please post your comments/questions on TSS blog above.




1. J FIncannon - June 15, 2015

Even though the idea is ingenuous it is not clear to me why it is better than the original ARRM concept of a Kevlar-like bag that cinched over the “asteroid”. Currently it sounds like ARRM is moving to an arm to pluck a boulder from a larger asteroid, but originally they had worked out how they could rendezvous with a rotating rock (after matching its rotation) and placing the bag around the rock and then fire some thrusters (not that large) with a certain moment arm and over time the asteroid rotation would cease. Yes, ARRM was only designed to move the object from one place to another, but it avoided the complexity of making a Xenon tight bag, which sounds hard to accomplish.

The guests proposed concept still requires finding the “asteroids” and I imagine the size is going to be close to ARRM’s limit, since it takes alot of fuel to move from beyond Mars to cis-Lunar.

Regarding his filling stations, it is unclear how these are managed since you need to maintain cryogenic temperatures to avoid boil-off, thus you need alot of power.

2. J FIncannon - June 15, 2015

I watched the good Doctor’s TED talk on his concept. Very interesting. I guess I need to read his technical paper because the concept seems short on power (solar arrays too small) and the mission trajectory analysis seems wanting (how much xenon to both fill the bag and provide fuel to the SEP engine?).

B John - June 15, 2015

Power is about bigger solar arrays and more time, who knows if it adds up economically but it seems doable for NEA’s in principle. I think one of the points is that one could use the gas extracted from the asteroid as propulsion mass. If the ion thruster uses xenon gas, maybe it could filter back some of the xenon it inflated the bag with as the extracted volatiles increase the gas pressure, and use it as propulsion mass?

It’s an interesting concept very different from the traditional Caterpillar(R) way of doing mining. When factors like gravity and atmosphere are removed, it affects all kinds of components (even a “simple” bolt gets less stress, but on the other hand gets super cold) and it should be expected that the optimal system for it will be very different. Maybe that’s why the mining industry isn’t interested in space mining? They have little more in common than the popularly used word “mining”.

J FIncannon - June 15, 2015

I heard a brief mention that the bag itself would have solar cells on it. Maybe that would be enough power.

If they had H2/O2 engines, then that would address the concern about even fuel. Or perhaps they don’t even need combustion, just blowing the gas out a nozzle. I doubt they would recycle the Xenon since ion engines are finicky about the purity of the fuel and would foul with <99.9999% Xenon.

3. DougSpace - June 13, 2015

The description of telerobotic mining given by the guest starting about 12:00 is so contrary to the type of ice harvesting that would be done on the Moon as to nearly constitute a straw man argument. His family’s experience with hard rock mining is not applicable to ice harvesting on the Moon because ice harvesting would not be hard rock mining.

His reference to teeth on buckets breaking at 0 degrees Celsius is not applicable because those teeth are probably steel working against hard rock. Of course they would start breaking at those temperatures when working against hard rock and using steel. But ice harvesting on the Moon would use aluminum which does not get brittle at cryogenic temperatures (consider the Space Shuttle main tank) and ice harvesting on the Moon will not involve hard rock. If it helps cement memory let me repeat: Lunar ice harvesting will NOT involve hard rock. Terrestrial mining illustrations involving very heavy equipment frequently breaking down is not applicable because terrestrial mining involves hard rock and deals with ore typically at far less concentrations than ice is at the lunar poles as proven by LCROSS.

There is no reason why heavy terrestrial mining equipment should be confused with the type of ice harvesting equipment that would be used on the Moon. I would hope that the following two pictures would be self explanatory as to how different they would be:

The amount of rock excavated in a terrestrial operation is probably 1,000 (WAG) times more than fluffy regolith would be excavated in lunar operations. Ice harvesting on the Moon would be done much more carefully resulting in less dust kicked up. If a no-contact (e.g. microwave) approach were used then there would be no dust. These more gentle operations and the processing of much less dirt will directly result in a lower rate of breakdowns.

Lunar operations should have redundant equipment and spare parts with easy release mechanisms to allow for the telerobotic replacement of parts. Lunar ice harvesting equipment should be developed first on a Earth in an iterative approach by engineers in laboratory environments which simulate vacuum, cryogenic temperatures, gritty regolith, 3-second control delays, and suspending 5/6th of the weight.

It would be nice if this more accurate understanding could be brought into the discussion the next time a guest brings up the inaccurate scenario of mining rock on the Moon using heavy equipment.

J FIncannon - June 15, 2015

I would not presume that we really know what the ice looks like on the Moon. If the ice is in some powdery, diaphanous, flaky form, then yes, it is not like rock at all. If a polycrystalline form, the strength of ice at only -55C can be as high at 8000 psi (www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA067583)! But if in a permanently shadowed crater, the temperature is very low. I do not have data for -249C (http://www.nature.com/news/2009/091217/full/news.2009.1149.html)
but the slope of the strength curve suggests >16000psi!

Examining some strengths of rocks show a similarity to this kind of cold ice.

We can always “heat up” the crater to a workable temperature. The same is true for the asteroid.

Do we know the strength of lunar regolith at this low (-249C) temperatures? It seems that if ice is really going to be collected in these cold spots, then you need to first warm up the area so that your robots can survive and to make the ground workable.

DougSpace - June 15, 2015

Here is a very fair assessment by Dr Spudis of the physical nature of lunar polar ice including the uncertainties involved:


The only thing that I would add is that harvesting using microwaves would be a way of extracting water in which the form of the water is not particularly relevant because microwaves would cause it to turn to vapor regardless of the original physical form. Under no circumstances do I imagine having to use ice harvesting equipment as though it is dealing directly with ice in a hard “rock” form.

J Fincannon - June 16, 2015

“Under no circumstances…”
To bad that you have such an absolutist opinion of lunar ice given we know very little about it. Yes, I had previously read Spudis’ article. Still, it is conjecture. Don’t take it as gospel. What is needed is a robotic explorer to probe the icy areas.

By warming up, you can use a variety of heaters besides microwaves if you are concerned about vaporization, although that can be useful too. And I expect you must heat an area up to get an ice/water harvester to survive as well.

4. Matt - June 13, 2015

Hello Dr. Damer, your idea to enclosure a small comet/asteroid by inflatable hull is really interesting concept. I have only a question. I understand that you would like to use gas friction to eliminate the body’s rotation. However, in this case the angular momentum of the comet/asteroid will transfer to your spacecraft (law of conservation of momentum). How much propellant do you need to slow down a 1.000 ton asteroid by help of thrusters to eliminate the angular momentum? It must be a signifikant value.

B John - June 14, 2015

Maybe it doesn’t need to be spun down at all with this concept? Nothing rigid needs to land on it.

The “asteroid mine in a bag” should have no need to match the asteroidlet (as in “moonlet”) while enclosing it in vacuum. When the bag is filled with gas the bag will indeed slowly start to spin and tumble. But is that really a problem if the bag could be station kept out of stiff contact with the asteroid?

After having extracted the available volatile surface resources, the “bagcraft” (not a new word, just a new meaning 🙂 should be able to undock and then despin its collected cargo. Instead of having to despin the entire mass of the asteroid. Maybe by already using some of it as fuel or as solar powered reaction mass. The extracted raw fuel resource has to be transferred from the bag content to a rigid tank anyway in order to be usefully processed and transferred to some client spacecraft for consumption. Maybe the bag itself should be evacuated of its gaseous content and left wrapping its asteroid by its tankcraft.

5. rocketaholic - June 12, 2015

interesting discussions

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