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“ Certainly still smaller bodies exist but cannot be seen from Earth. Table 4.8 summarizes available information on the widely variable surface compositions of asteroids (Lunar, 1978) . The predicted large quantities of rare elements, such as chromium and vanadium, and common metals such as iron and nickel might ultimately have great importance to terrestrial markets and space industries (Gaffey and McCord, 1977; Kuck, 1979) . Industrial facilities and habitats constructed from asteroidal materials would make possible the rapid spread of humanity throughout the Solar System. ”

“ Space manufacturing directly leverages the effectiveness of any system for transporting goods and materials off-Earth if the value added to the space products is less than the value added by launch of functionally similar goods from Earth (Goldberg, 1981) .
STS components such as exhausted hydrogen/oxygen propellant tanks call be used for raw materials. Shuttle external tanks could provide approximately 140 kg/hr of alumina and 10 kg/hr of other elements (e.g., plastics, residual propellants) for early development of manufacturing procedures and products, assuming 30 Shuttle flights per year. ”

“ When launch charges reach $1/kg a large Earth-to-LEO traffic becomes reasonable, since most terrestrial goods are valued at $1-2/kg (Ayres et al., 1979) . However, if space industry someday is to approach cost distributions typical of terrestrial industries, then the supply of bulk or raw materials from the Moon and the asteroids must fall to a few 4/kg (Criswell, 1977a, 1977b) . On an energy basis alone, this goal appears achievable using high throughput lunar-mass drivers and relatively cheap solar energy (O'Neill, 1974) . ”

“ Refining and processing system designs would be significantly affected by the structural configurations of asteroids.
The third and final phase involves large-scale utilization of asteroidal materials either on-site or following transport into near-Earth space. There is a need to develop systems for despinning asteroids, emplacing powerful thrusters, then returning the body to near-Earth space. Ultimately, whole factories might be delivered to or evolved upon individual asteroids. ”

“ A survey of Solar-System resources available to mankind in the near-, mid-, and distant-future is appropriate in evaluating the potential of the SMF mission concept. Such background is necessary to identify terrestrial and lunar resources, asteroidal materials, and various additional sources for space manufacturing feedstock. ”

“ A few comets have been named after those who made extensive studies of their motion (e.g., Halley and Encke) . Comets with periods less than 200 years are arbitrarily called "short-period" and are often written with a preceding P/ for periodic (e.g., P/Tempel 2) . Long-period comets are sometimes preceded by C/ just to designate they are comets (e.g., C/West) . When one observer or combination of observers discovers more than one short-period comet, the names are followed by an Arabic numerical in order of their discovery to tell them apart (e.g., P/Tempel 1 and P/Tempel 2) . ”

“ Mankind has launched about 5000 t into LEO since 1959. Most of this was propellant for Apollo lunar missions and for satellites hurled into geosynchronous orbits or into deep space. Approximately 1000 t was hardware. Averaged over the last 10 years, humanity has ejected mass from Earth at approximately 0.05 t/hr or 400 t/yr. ”

“ At some point in the future, major mass fractions of space facilities may be constructed of nonterrestrial matter. Space hardware should be produced in orbit at the rate of 10 kg/hr to match the 1970s and anticipated 1980s launch rates. ”

“ Though the team can offer no conceptual designs for such systems, it is intriguing that the solar wind output of most elements rivals or far exceeds their corresponding current annual terrestrial production rates. ”

“ Earth's upper atmosphere also may prove a valuable source of nitrogen and oxygen for use at LEO and beyond. At 200 km altitude a scoop 1 km in radius oriented perpendicular to the orbital motion intersects approximately 4 t/hr of molecular nitrogen and 3 t/lir of atomic oxygen. Physical convergent nozzles might be used to collect either N2 or 0+, and a convergent magnetic field might be employed to recover O+. Power must be supplied to liquefy the gases and to accelerate a portion of the gathered material to maintain orbital velocity. ”

“ The composition of lunar soil is essentially the same as for lunar basalt, with grain constituents including agglutinates, basalt clasts, anorthite clasts, plagioclase, olivine, ilmenite, and glass. The average grain size is approximately 40 um, but lunar soils often display bimodal size distributions.
Plutonic anorthosites are present in the highland areas. The mineral distributions in three anorthosite samples collected during Apollo missions are given in table 4.5. ”