New Mars Forums

Google billionaires, James Cameron backing space resource venture.
By Alan Boyle

Today's media alert says the new company "will overlay two critical sectors — space exploration and natural resources — to add trillions of dollars to the global GDP. This innovative start-up will create a new industry and a new definition of 'natural resources.'"
    "That sounds like asteroid mining," Christopher Mims writes on MIT Technology Review's "Mims' Bits" blog. "Because what else is there in space that we need here on earth? Certainly not a livable climate or a replacement for our dwindling supplies of oil."
    Parabolic Arc's Doug Messier, meanwhile, writes that the venture will be an "extraterrestrial mining company."
    Diamandis has said on more than one occasion that he's intrigued by the idea of digging into asteroids, for materials ranging from water (for fuel as well as for astronauts) to precious metals such as platinum. The Verge points to a TED talk in 2005 where Diamandis discusses his dream, while Forbes magazine has brought up the subject with him more than once in the past few months.

http://cosmiclog.msnbc.msn.com/_news/20 … ce-venture

  Bob Clark

It would be very hard to build a Bessemer converter that worked in a near-vacuum CO2 atmosphere.  Direct reduction would be much better.  Easier to do,  because it's all closed reactor vessels that don't care what's outside. 

You'll have to melt the sponge iron in an electric furnace,  adding just the right amount of carbon and alloying elements.  The electrical demand to power that is enormous. 

We do it all the time here with our electric grid,  but on Mars with no grid at all,  that's going to take dedicated atomic power of large capacity.  I would suggest a big water electrolysis plant powered by a big reactor.  The electrolysis goes offline in favor of the furnace when making steel.  That way the reactor itself runs a constant power. 

GW

So if that machine found a collection of attributes reasonably near a favored location and that prompted the first settlement to be established there what would that collection be?

I have this list of probable materials in Hellas.
-Magnetic Meteor Iron.
-Glaciers, and probabbly other ice under the soil in places.
-Thicker atmosphere.
-Not a true polar location (Not as harsh as the poles).
One other thing I think is possible is Copper Sulphate?
http://spacefellowship.com/news/art2077 … lakes.html
http://en.wikipedia.org/wiki/Copper(II)_sulfate
I am presuming that if the last part of the wet period of Mars was acid as is said, copper in the soil and rocks would have been leached out, and would end up as disolved materials in lakes in Hellas, and that when those lakes dried up, there would have been salt pans.  I don't know how to get copper out of copper sulphate, but I would imagine it can be done somehow.

I might also what to find salt domes and perhaps even petroleum in association with those.  But, I am not thinking that such a convenience is likely to be near the site which would be selected, but maybe.

I guess a really big need would be the resources to make good glass with, but I don't know what that is yet.

The tires could alway be replaced by the wire mesh tire system the lunar rover used. I suppose its springiness would even mimic the shock absorbing ability of pneumatic tires. Zubrin seemed to think that liquid methane and liquid oxygen could be used in internal combustion engines with atmospheric carbon dioxide as a dilutant. One could also recycle the exhaust as a dilutant gas. Yes, Spacenut, if you google "utility vehicle" you'll find four other manufacturers listed. The gator struck me as cute and light, a sort of lunar rover for crossing the Rocky Mountains. Of course, it may be too small for men in space suits!

I made the subject name start similar to "Mars Colony Cement and Concrete".  In fact I was considering putting this there and you can certainly move it if you want.

In this case I am hoping that forms would allow natural materials such as dune material to be "Vacuum welded/Sintered" into blocks by the material being exposed to a higher vacuum than is natural on the surface of Mars, and also with the application of heat.

Here are some links for reference:
http://en.wikipedia.org/wiki/Vacuum_cementing
http://en.wikipedia.org/wiki/Sintering

This would involve molds, a vacuum, and a heat source, and perhaps a Hydrolic Ram.

The mold itself could be evacuated, or I think more probabbly a building would be constructed where the pressure is evacuated, a large vacuum bell.  This should be more practicle to do on Mars as it is now, than it is to do on the Earth (~6MB vs ~1000MB+).

I presume that people in counterpressure suits could work inside of that chamber, as easily as out on the surface of Mars.

Obviously I am attracted to the dunes because there may be a general similarity of the particles in a dune, and these might be cemented with ice, but otherwise it should be possible to shovel the stuff up.

This then would be a "Ceramic" material.

However, there has been a discussion of collecting magnetic iron from the surface of Mars.  I wonder if that could be cleaned could it also be sintered?  Not likely to be a high grade metal material, but maybe as good as Cast Iron?  In such a sintering process, could fibers of a material with a equal or higher melt point be imbedded, to provide greater strength?  Sintering occurs at a temperature below the melting point of the materials.

Another thought is could the magnetic iron collected be ground down in a "Balling Drum" to a powder, and that poweder also be used to print 3D objects inside of the vacuum bell, using Vacuum Welding/Sintering?  If structured and with fiber additives, perhaps something quite strong could result, without the standard steel making process.  I used to work in a place with "Balling Drums"  used to grind Taconite Ore. It was a wet process.

RobS wrote:

...
The three decks of the capsule-shaped vehicle together have a volume of 52 cubic meters; the Space Shuttle provided 68, if I recall, so it's similar in size to the shuttle. The mass includes 1.5 tonnes for an inflatable and furniture (Zubrin used 200 kg for a two-person inflatable). I am assuming a crew of up to 7. If the inflatable fails en route they'd have to retreat into the Gryphon and the space would be very tight, but presumably people would survive. The 10 metric tonnes of cargo would be the 4 metric tonnes of consumables needed on the trip out plus 6 metric tonnes of various things the crew of 6 needs on the surface (some essential equipment, some consumables). The rest of the consumables and equipment arrives by Hohmann trajectory 2 months after the crew arrives. Ideally, the hab can be retracted, deorbited to the Martian surface, and used there as well.
The delta-v of 4.4 km/sec is carefully chosen; that's what you need to go from low Earth orbit to Mars in 6 months (4.3 plus 0.1 for mid course corrections). You need 4.1 km/sec to go from the Martian surface to low Mars orbit; very similar. The idea is to refuel the vehicle in low Earth orbit, launch to Mars, aerobrake, refuel in low Mars orbit sufficiently to land, refuel on the surface, return to low Mars orbit, refuel there sufficient for TEI, and head for Earth. The fuel in Mars orbit could be made on Phobos, Deimos, or the Martian surface and delivered. A round trip would require 55 tonnes out, maybe 5-10 tonnes to land, 55 tonnes to return to Mars orbit, and about 15-20 tonnes for TEI.

I like the idea of having refueling stations in orbit at Earth and Mars, and the reusable shuttle between the two planets. These two concepts might indeed make possible Elon Musk's concept of a Mars ticket for a few hundred thousand dollars.

Bob Clark

Large payloads of 20 plus landing on mars still has not been solved...but still 4 launches to get the 20 plus to mars, is still alot of launches to get in a 2 month window....for each unit for leg of use

Let me sum the state of the argument.

Wikipedia, bad. Zubrin's thoughts on anything, worse.

Mars, Luna- space. They are all so vastly different from our historical experience as to make any analogy laughable. The Frontier model  is an over simplification to win hearts and minds for those who have want a fantasy to fill their canvas.

I really don’t want to waste our collective time by showing you the fallacy of some out dated historical model and how it simply cannot apply to space exploration, or by association, colonization, but I will, if I have to.

Bamboo is actually a decent structural material.  Good strength/weight,  and rather easy to work.  Joining seems best done with lashings,  actually. 

You will have to have a place with air and water to grow it in.  There's osmotic pressures of transpiration to consider,  among many things. 

I doubt we'll bio-engineer anything that could live outside until Mars is terraformed.  The water vapor pressure problem is insoluble at 7 mbar dry CO2. 

GW

That article says mid latitudes (30-60 degrees) not the equator. But there must be ice near the equator somewhere, too. I said "as close to the equator as possible" for this reason.

Hellas would be interesting and low. The Chryse lowlands near the mouth of Kasei would be interesting, too, but Chryse doesn't seem to have a lot of subsurface ice. It's too bad.

P.S.: Somewhere, someone said the Dragon's heatshield seems to be only 8% the mass of the vehicle, rather than the normal 16%. What's the evidence of that? I'd like to see that info.

3.8 km/sec and 6.4 km/sec are the numbers for Hohmann (minimum energy) transfers, which take 8-9 months each way and are not free return trajectories. If you go a bit faster (4.3 km/sec outbound and about 7 km/sec inbound) you make the trip in 6 months instead and you put yourself into a 24-month solar orbit, so if you miss Mars on the way out (say, because of damage to the craft) you come back to Earth anyway. You also cut down on consumables.

Zubrin calculates that a Falcon Heavy putting 53 metric tonnes in LEO, including a hydrogen-oxygen stage, can push 17 tonnes to trans-Mars injection, put 14 metric tonnes into orbit, and 11 metric tonnes on the surface. I suppose those numbers represent 3 metric tonnes of heat shield and retrorocket fuel and 3 tonnes of TMI staging. If you can protect the stage with your heat shield, you can probably land it on Mars as well, but that probably means a bigger heat shield and more landing fuel, so your 11 tonnes of cargo diminishes to maybe 10 or 9. As we have noted elsewhere, the "Red Falcon" project manages to put even less on the surface, probably because they are using bigger margins and RP1/LOX propellant all the way.

Nine or 10 tonnes may be enough for a 1-way trip for 1 or 2 people, but it'd be hard to include enough other stuff to make it a round trip. If you already have solar panels and a robotically drilled water well, it might be barely enough, but I doubt it. You'd do better by launching two Falcon Heavies, one with a dedicated LH2/LOX stage to which the earlier launch would dock. Both Falcon launches would need to include propulsion stages, but the one with the cargo would have a much smaller stage and your payload mass doubles; a bit more than doubles, probably. If you can land 22 or even 24 tonnes on the surface, you're getting close to the Mars Direct ERV (28.6 tonnes).

Louis, why are you talking about building rockets on Mars? I could see it several decades after human arrival, but sooner? The Falcon system is designed to be reusable. The Falcon second stage masses about 53 tonnes, fueled, and is being designed to return to the Earth's surface from low Earth orbit. A Falcon Heavy could put an entire second stage into Earth orbit and after it burns its fuel to send cargo on its way to Mars, the second stage could actually land itself on Mars, where it could be refueled and used as a rocket. It looks to me that Musk has the problem of supplying Mars with rockets solved already.

Besides, 100 people would build a pretty primitive rocket; the Falcon system requires a thousand or two. Why should 100 people build a primitive rocket when they can get a sophisticated one that has been tested many times?