On Monday, May 29, 2017 at 2:21:39 AM UTC+12, Jeff Findley wrote:
First, this isn't my "subject", it's the title of this article:
Mining the moon for rocket fuel to get us to Mars
May 14, 2017 8.04pm EDT ?Updated May 18, 2017 9.01am EDT
http://theconversation.com/mining-th...-to-get-us-to-
mars-76123
I saw this article (or a variation of it from another online
publication) on Twitter. I replied something to the effect that this
article glosses over all of the hard stuff, like the fact that the lunar
soil and rock is horribly abrasive and that mining equipment isn't
anything like the lightweight rovers that NASA/JPL has flown in the
past. For crying out loud, JPL keeps using ALUMINUM for the rover
wheels to keep them light, even though they're wearing holes in the
things after less than 100 miles. Mining equipment can't be that weak!
Anyway, I replied that mining equipment is *really heavy* because it's
made of steel and hardened steel.
The response by one Twitter follower was along the lines of, "That's why
the mining equipment will be built on the moon from local materials".
At that point, "I couldn't even". I mean WTF? So, to build mining
equipment on the moon, you're going to build an entire freaking factory,
from local materials?!?!? So, WTF are you going to use to mine the
materials to build the factory?!?!?!?
Don't get me wrong, I think *eventually* we'll be mining the moon for
water to turn into LOX and LH2 (or possibly methane) to supply a fuel
depot in lunar orbit. But, needless to say, I think the supporters of
this notion are daft if they think it's going to happen in the next 20
years or so by building a freaking factory on the moon that's capable of
building mining equipment that's not JPL class "toys" that wear out
faster than you can build them.
Jeff
--
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These posts do not reflect the opinions of my family, friends,
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Development is non-linear and results in a technological singularity. Growth is not
y = EXP(t), t=0 to infinity
it is
y = 1/(t-1), t = 0 to 1
Where one is the year 2035AD and 0 is now.
https://en.wikipedia.org/wiki/Technological_singularity
The singularity is generally thought of as a time when machines are smarter than people, and this is true, however, it involves more than that. Anything it is physically possible to do, will be doable after this date.
The Delta launcher took 30 years and $60 billion to develop. SpaceX took 15 years and $10 billion. RocketLab took 4 years and $100 million and its present capacity is the capacity of the original Delta space launcher was less than the Electron (RocketLab's launcher). The trend toward more capacity at less cost is obvious. The singularity approacheth.
The discovery of water ice on the poles of Mercury, have awakened many to the possibility that water is a lot more common on rocky planets than previously thought. It seems protons in the solar wind, interact with silicates in the rocky planet to create water and if a rocky planet or moon can hang on to it, that can be accumulated, and used as a propellant resource.
The use of Earth's moon and moons in general as resource bases is energetically very favourable. Not only around Earth, but around Mars. Deimos and Phobos are thought to have lots of water in them as well. Since they have very low densities.
So, finding water is the first step.
An abundance of power is the second step.
In the 1950s this was thought to be nuclear fission power. Today this is most popularly solar power. Tomorrow, it may be nuclear fusion power.
Advanced tooling is the third step.
Again, in the 1950s, specialty equipment was made to transform life on Earth, making all manner of expensive consumer items more cheaply than it had ever been made before.
This requires a lot of expensive tooling be designed fabricated and tested, and then transported. If lightweight enough, it really wasn't a burden for space applications. So, instead of making a million cans of soup a day, or V8 engine blocks, we build highly automated machinery, that's lightweight, operates with a mobile power source, and makes what small groups of individuals need, to make stuff from materials found around it without a lot of labour.
Many social scientists have pointed out that the wars that have been fought throughout the 20th century have really been a reflection of the social conflict between a ruling oligarchy and the vast majority of humanity they have exploited. That is the wars we fight are to keep the tremendous productive capacities from being used to eradicate poverty hunger and want, which is how the ruling elite maintain control. War provides a simple explanation of this, and conveniently absorbs the expanded productive capacities.
One of the benefits of space program of this nature, where the engineers and scientists that brought you everything from contact lenses to soda pop, now turn their considerable skills to producing small self sufficient communities that eke out a living on the moon or asteroids, would have been the advanced tooling to live on the moon, would have benefitted everyone on Earth too.
Vertical farms of today lean heavily on the studies of the 1950s through 1970s space colonies. Had these space colonies been funded at the time, we would likely have licked hunger and starvation as well as poverty, and already have an abundant world of plenty. This would have changed social structure, and even us genetically, without the constant threat of violence a radically new sort of existence opens before us.
https://www.youtube.com/watch?v=0jFGNQScRNY
Since high incomes in a population translate to low birth rates, particularly as women participate equally with men, overpopulation would have been licked by 2000 as well, and will be licked by 2050 in any case.
This was written about by the futurist Herman Kahn in the 1950s and 60s - and was commented upon seriously. Some feel this is why the aggressive space program of the Kennedy Administration was abandoned in favour of the War in Vietnam by the deep state and the ruling oligarchy that runs it. The funny thing is, had they adopted and embraced Kahn's vision of the future (apart from his willingness to engage in nuclear warfare) the oligarchy would have been 'first among equals' in the post singularity age. As it stands, they are growing ever more reviled, and will not likely make it through the singularity unchanged.
Today we have 3D printing, early versions of AI, and the possibility of 'clanking replicators' which reduce the overall cost of the process described above. This permits private companies to do what it took than entire societies to do in the 1950s. So, Elon Musk and others can today make a decision to develop off world colonies and seriously do so.
The long term benefits remain the same, yet the scale of the enterprise is that of a corporate programme, rather than a national programme like a war, or a highway system, or a rail system, so today we see private companies announcing plans that were discussed as a social goals in the 1950s, and we also see the erosion of the power of governments.
Social scientists point out that the ruling oligarchy always used governments to fool people into believing they had power, when in reality they had owners and debt. With the arrival of the singularity in the next few years, this is no longer a tenable position. So, the oligarchy is appealing to direct power politics, to quote PNAC.
http://www.antiwar.com/orig/stockbauer1.html
So, look for corporations to dominate going forward, until the erosion of government has proceeded so far, that power politics itself begins to erode and we see corporate owners power erode as well. This is not the socialist or communist prediction of the rise of the proletariat. Government at that time will have long been discredited. It will be the rise of an emergent system that depends heavily on AI and the internet, and will be beyond the control of anyone or any group.
Tomorrow, post singularity, we will have advanced AI and utility fog. This will allow individuals to wish to do a thing, and if that thing is physically possible, and they have access, the utility fog will make it so. Access and how to get it will shape post singularity society every bit as much as money and how to get it shapes our society today.
In a rational society the transition would be a smooth one. Humans are rarely rational.
Vector Currency
https://www.youtube.com/watch?v=DOkCXiqnEDA
Utility Fog
https://www.youtube.com/watch?v=Q1CKRltKS7g
http://www.nanotech-now.com/utility-fog.htm
Moon bases as resupply for interplanetary travel
So, to recap, for moon bases to work, we need;
(1) Water on the moon we're going to use,
(2) An abundant low cost power source,
(3) The means to turn that resource into rocket fuel,
Of course, the argument has always been, if we have a lightweight portable nuclear fission power plant, or a solar pumped laser, or a fusion power plant, why not make a fission, laser, fusion rocket and dispense with chemical rockets altogether?
Well that's a good argument, however, we can imagine details - such as fission power is too dangerous, or solar power to bulky, and so forth - that says we need to have them at stationary bases making chemical fuels for chemical rockets.
Since actual decisions must await actual programmes that actually do something, one can argue interminably about what's better. Yet, to understand a thing its good to think it through, and give it real consideration.
So, let's do that now.
Deimos Water Company
http://www.spacefuture.com/archive/t..._company.shtml
According to this study, If you look at the energetics involved, Deimos - the outermost moon of Mars - is the best place to mine water to support an interplanetary transport system. The link above goes into detail and worth looking at since the details will also work with a water supply on the moon with some slight variation.
The discovery of water at the moon's poles also make it an interesting possibility.
http://www.space.com/27388-nasa-moon...ons-water.html
Practical Program that may be started today;
Now, the development of low cost solar panels, along with low cost MEMS based ion rockets that can use water efficiently as propellant, and efficient laser beaming of power, shape the sort of system that is suitable.
(1) Low-cost, highly reusable, chemical booster on Earth;
(2) Low-cost highly reusable laser ion booster is developed;
(3) Solar power satellite that beams power to where its needed, is developed;
(4) Launch three solar power satellites into GEO separated by 120 degrees of longitude;
(5) Launch five more solar power satellites into the Earth/Moon Lagrange Points;
(6) Launch five more solar power satellites into Sol/Earth Lagrange points
(7) Establish a space station in LEO to transfer people and materiel between Earth and Moon
(8) Use space station components and beamed power ion stage to create carrier craft
(9) Use beamed power ion stage to create freighter craft
(10) Develop deep space chemical powered lander
(11) Send a fleet of spacecraft forth first to the moon, then to Deimos, then to Mars
(12) Establish a reusable link to fly regularly throughout the Earth/Moon/Mars system
Mars has a source of carbon, which is the carbon dioxide in its atmosphere. So methane is a possible propellant there. The moon, and Deimos may not have such an easily tapped source. So, we may have to use hydrogen as a fuel in that case. In any even, multi-mode tankage, and multi-mode engines, are preferred over highly specialised single use types. At least ones that can be easily retuned.
Methane Rockets
http://www.dlr.de/Portaldata/55/Reso...5-0212prop.pdf
Methane Propellant
LNG: 422.5 kg/m3 density
112 K - BP
91 K - MP
309.6 seconds - Isp (with LOX, Sea Level)
368.9 seconds - Isp (with LOX, Vacuum)
3.21 - O/F Ratio
830 kg/m3 - bulk density with LOX
Hydrogen Propellant
LH2: 71.0 kg/m3 density
20 K - BP
14 K - MP
391.0 seconds - Isp (with LOX, Sea Level)
451.0 seconds - Isp (with LOX, Vacuum)
6.00 - O/F Ratio
280 kg/m3 - bulk density with LOX
Oxidiser
LOX: 1,140.0 kg/m3 density
90 K - BP
54 K - MP
The point of this is that for a given weight of oxygen, you need 1.86x as much LNG by weight, and 3.18x the volume of hydrogen as LNG.
Weight and Volume Comparison
kg density volume ratios
LOX/LH2
1000 71 14.1 2.676 - LH2
6000 1140 5.3 1.000 - LOX
LOX/LNG
1869 422.5 4.4 0.841 - LNG
6000 1140 5.3 1.000 - LOX
Common Core Interplanetary Module;
So, what pops out from this analysis is that we could have a common deep space module that is configured as a zero boil off tank for LH2, LNG, or LOX, and making use of the 'wet lab' concepts from the 1950s through 70s, from which Skylab was built, we make our tanks big enough to live in is the minimum. Making them spherical, with connections built between using a variant of the common berthing mechanism on the ISS.
Consider then;
A sphere 5.24 meters (17.2 ft) in diameter, holds 86 tonnes of LOX, 5.36 tonnes of LH2, or 31.9 tonnes of LNG. It also has the same interior volume as the Harmony ISS module. 75.5 cubic meters.
Sphere packing
http://math.mit.edu/classes/18.095/2...lect_notes.pdf
Now, if we have 2 LH2 modules and 1 LOX module, we will only be able to use 74.7% of the LOX on board, which is actually okay, if you plan to breathe oxygen and can make use of it that way. You put in only what you need. As a habitation module, a 17.3 ft diameter floor, occupied on both sides, give a total of 464 square feet (43 sq m) living space, and life support and other hardware is attached through the berthing mechanism.
If we have 1 LOX modules for each 2 LNG modules we make use of 59.4% of the LOX for propellant, leaving spare oxygen if needed for breathing. Alternatively, we only fill the LNG tank up 84% capacity, or take extra if we have use for LNG at our destination.
Hydrogen and Oxygen can be used to produce chemical power on demand, using a fuel cell, if needed. Natural gas and Oxygen can be used likewise, with an appropriately configured fuel cell.
https://www.youtube.com/watch?v=xK3yxn69q8U
With MEMS based propulsive skin built into the exterior of each zero boil off tank the units are easily moved and can be configured into a wide range of uses.
The same module holds
86.00 tonnes of LOX,
5.36 tonnes of LH2, or
31.9 tonnes of LNG.
A subscale oxygen tank - 3.8 meters in diameter - holds 32.2 tons of LOX - is perfectly suited for the larger LH2 tank - provides an extra capacity of LOX for LNG operations - and a smaller habitable module, and smaller systems generally.
31.9 tonnes of LNG require 102.4 LOX - 16.4 more tonnes than is contained in the larger module. So, many configurations are possible with one or two systems such as these.
The spheres are built around dodecahedral frames and you may also put the smaller sphere inside the larger, which also has great utility.
28.2 tonnes of water based electrospray ion propellant may be stored in the smaller sphere. Electrospray ion engines with 15 km/sec exhaust speeds built into the propulsive skin of the spacecraft, allow a combined module to receive energy and communications via laser or maser beam from solar power stations, and carry people on board. Waste water properly processed may also be used as propellant for such engines.
Using LOX/LH2 on the moon, we have 4.4 km/sec exhaust speeds to carry out 3..2 km/sec delta vee from the lunar surface and back.
With an 11% structure fraction, this means we must expend 1384.6 kg of LH/LOX propellant for every 1,000 kg of payload.
On Deimos, there is no gravity well to speak of, and with the atmosphere on Mars, you can aerobrake, so things are must easier there.
However, there is another possibility. Namely, the ability to use an electromagnetic cannon to shoot material from the lunar surface into orbit.
https://ntrs.nasa.gov/archive/nasa/c...0110007073.pdf
So, the rocket based delivery system is used for people and other fragile cargo that cannot be transported easily by launcher.
So what would a mission look like once all the parts and pieces were in place?
You launch on a highly reusable multi-stage rocket into LEO from Earth. You wait at the space station for the arrival of a beam powered ion engine deep space ship. You transfer to that ship when it arrives. It flies to the moon and enters moon orbit. It is joined by a rocket supply ship, which you can take to the lunar surface, and propellant supply drones launched by electromagnetic launcher.
As you while away your time on the lunar colony, your interplanetary ship is joined by others. When the planets are aligned, its time to leave, you blast back to lunar orbit, and depart aboard your beam powered ion rocket craft.
Arriving at Mars you receive power from the Mars solar stations, and slow into Mars orbit, landing, though docking might be a better phrase, at Deimos.. There you take a local shuttle down to the Martian surface. Using chemical rockets to transfer to a re-entry altitude above Mars, and aerobrake to slow to a soft landing, which is accomplished again by chemical rockets. Chemical rockets boost you out of Mars' atmosphere. Though even here, due to the low density of the carbon dioxide atmosphere, electromagnetic launchers are used on Mars for resupply. Particularly at higher altitudes.
http://newmars.com/forums/viewtopic.php?id=2609
Still there is sufficient oxygen and nitrogen on Mars to pressurise domes made of plastic from materials extracted from water and carbon dioxide -to create Earth normal atmospheric conditions inside.
https://www.linkedin.com/pulse/20141...of-air-on-mars
On Mars people can return to the Moon and then to Earth. People can also choose to rove deeper into the solar system, to the asteroids and beyond. The asteroids have considerable water in them. Ceres has more fresh water than Earth! Self replicating machine systems will rebuild them into thousands of open air space colonies.
https://www.linkedin.com/pulse/how-f...o-william-mook
This is before we build photonic thrusters that accelerate us to near light speed using a large fraction of the sun's output.
https://vimeo.com/40197828
https://www.linkedin.com/pulse/20140...e-in-our-reach
https://www.linkedin.com/pulse/indus...s-william-mook