NOTE: Space Shuttle External Tanks contain a fair amount of copper, an element not too common on the Moon. ETs could be processed in LEO at solar powered space stations that cut up the tanks with CO2 lasers and grind up the metals, separate and smelt them. Titanium and aluminum from ETs could have construction uses in LEO. The copper could be shipped to the Moon with efficient ion drive tugs. Some ETs are made of lithium/aluminum alloy and these could be a source of lithium which is also rare on the Moon. Lithium can be used as coolant in fission reactors. Or the Li/Al tanks could be cut up and the metals sent to the Moon as is. If a Shuttle Derived Heavy Lifter is devised to orbit payloads and the ETs are rocketed to orbit instead of ejected they could be an important resource for LEO, GEO and the Moon. Cargo modules made of graphite composites, which have half the density of aluminum, are lighter than magnesium and even stronger than steel could be another resource to cannibalize for the Moon. Styrofoam and plastic packing materials for the cargos could also be useful. Ejecting ETs is a terrible waste of a valuable resource. Even the polyurethane foam could be removed from ET surfaces before cutting up the tanks and shipped to the Moon by ion tug.
If hundreds of ETs are orbited as part of a massive push to the Moon for energy and other space industries we could get about two metric tons of copper up there with each launch and several hundred tons of copper altogether. Used wisely it will go a long way. If say we mass produced ETs in robotic factories on the cheap and used advanced Shuttle Orbiters and a cargo carrying SDV to build space hotels for tourists and space factories we might orbit thousands of ETs before a better rocket is developed. ETs as is can be used as space station modules, spaceship hulls, surface habitat (buried under a few feet of regolith for thermal, radiation and micrometeorite protection), storage tanks for fuel depots, tubes for huge space telescopes; raw metals for construction, thin aluminum foil reflectors to increase solar cell output or heat boilers for turbogenerators, make antenna dishes, concave reflectors for solar smelting furnaces, aluminum wire, and even rocketfuel when powdered and mixed with LOX. Using the ETs gives us another 25 to 30 tons of useful payload per launch and improves the economics of each space launch, even if the ETs are as expensive as they are now; however, robotic mass production could reduce their price tremendously and make the financial picture even more lucrative, especially when we are bringing in billions, perhaps hundreds of billions, of dollars worth of helium 3 every year and selling gigawatts of electricity from SPSs.
At two cents per kilowatt hour one gigwatt of SPS power is worth 175 million dollars per year and the world in 2050 will use about 50 terrawatts or 50,000 gigawatts; so the sale of merely one terrawatt (1000 GW) from SPSs is worth 175 billion dollars a year! And that's at two cents per kilowatt hour, as cheap as coal or uranium. With largely automated assembly line style rocket stack assembly and launch preparation, the cost of launching a Shuttle Derived Heavy Lifter by private enterprise could be slashed. Rockets could even be launched from an equatorial or near equatorial launch base to take advantage of Earth's rotational speed and do away with the need to expend fuel and time to change the orbital plane of the Orbiters and Cargo Modules. Space dock stations and fuel depots would be located in equatorial or near equatorial orbits unlike the ISS which is orbiting at about 50 degrees to the equator. Orbital plane changes take a lot of energy and thus orbital maneuvering fuel.
A couple of tons of residual hydrogen and oxygen remain in ETs after each launch and these too could be used for atmospheres, water, fuel and fuel cell reactants. We've got to use every last bit. When agriculture is going we will use every part of the plants we grow and if livestock is raised every part of the animal. It's also possible that we will culture animal cells or "meat cells" in vats and not have to deal with livestock. We'll still need nutrients to feed the cell cultures and inedible parts of plants like roots, stems and leaves could be processed with sulfuric acid to break the cellulose down into glucose. Proteins or amino acides can be preciptated out with trichloro-acetic acid. I worked in a lab once and that's what we used to get the protein out of bacterial cells for analysis. Enzymes can be used to break proteins down into amino acids. Fats can be gotten by squeezing the oil out of dried roots, stems and leaves and digested further with enzymes. Minerals can be dissolved out with boiling water. Genetically programmed bacteria can make enzymes. So we can produce plenty of nutrients for the meat cell cultures. Some plants like hemp could be farmed to get fiber for paper, string, cloth; all which will be recycled, and oil that can be mixed with lye to make soap. There is sodium on the Moon to make lye. It's as simple as electrolyzing solutions of sodium chloride to get NaOH and HCl then electrolyzing the HCl to recover chlorine, a rare element on the Moon, and reusing it. Also, if we can get disodium oxide, Na2O, straight from Moondust we can just react it with water to make NaOH.
Aglae like Spirulina could also be cultivated. This stuff grows like wild, doubling its mass four times a day, so we could harvest lots of it daily and use it for food. It is high in protein and can be mixed with wheat flour or corn meal to increase the protein content of breads, biscuits, cakes, and other foods. We could extract the green chlorophyll out of it with ethanol, made by fermenting glucose, and use the chlorophyll as a green pigment for inks perhaps and as an odor absorber. Or we could eat green bakery goods. Is the Moon made of green cheese?
Finally, we could use bioleaching, the use of bacteria to extract trace elements like copper, zinc, etc. from Moon dust. |
