100 years on
Magazine Within a Magazine. Celebrating 200 Years of Flight
- By the Editors
- Air & Space magazine, January 2004
(Page 2 of 4)
Space Elevators
Once relegated to the world of science fiction, space elevators have gotten serious attention in recent years as a means to lower the cost of reaching space. A series of NASA and non-NASA conferences have concluded that the basic concept is feasible, although the engineering capability is not yet in hand. It could be in as little as 10 or 15 years, however, according to some experts.
The idea is to anchor a long-and extremely strong-cable at the equator, extending up past geosynchronous orbit, 22,000 miles above the Earth's surface. A "car" attached to the cable and propelled by a variety of means would move up and down. By the time it reached geosynchronous altitude, the car would be moving at orbital velocity (still anchored to the rotating Earth), and could be handed off into orbit. Or, from higher altitudes where it would have even more velocity, it could be slung out and away from Earth.
The biggest technical stumbling block has been developing a material strong enough to be used for the cable. Engineers believe they have found a solution in carbon nanotubes, a synthetic material far stronger than steel now produced in the laboratory. That breakthrough leads some Space Elevator gurus, like Bradley Edwards of the Institute for Scientific Research to predict that simple elevators can be built in the near future with investments amounting to several billion dollars.
Solar farm/hydrogen fuel depot
The hydrogen economy doesn't begin to take off until the early 2000s, when the four-wheel automotive industry begins serious development of fuel cells and other systems to escape the cycle of combustion of hydrocarbon fuels, in which ancient methane, petroleum, and coal are burned, releasing unwanted atmospheric byproducts. Hydrogen is initially derived from methane and ethanol generated through 20th century processes. The bio-engineering of existing species of plants that can survive-and even thrive-in irrigation with sea water opens up vast desert areas to the restoration of biomass, and in the short term, eliminates concern about shortages of traditional hydrocarbons while virtually doubling the absorption of atmospheric carbon dioxide.
Moving in parallel with these events are incremental, compounding improvements in the non-dynamic generation of solar energy from static, solar cells, initially, and later, from the combining of quantum solar generation as provided by the original solar arrays of the 1900s with the bio-engineering of bacteria that work in conjunction with the electrical cell to improve efficiency by a factor of three. The steady progress in traditional solar generation is the "tortoise" to the thermonuclear-fusion movement's "hare." (A popular 2102 hologram reads, "Fusion power is 25 years away, and it always will be," as an arch comment on the long-illusive technology of fusion.)
Dynamic solar energy from the heating of various media by large complexes of focusing mirrors and lenses driving some fluid from liquid to high-energy gases to turn a rotating power generator is under continuous development, but offers only minor improvements decade on decade. It is unable to keep up with the advances in static cellular arrays generating direct current to inverters, which convert it to standard AC. Lack of efficiency gains combined with high capital costs lead to the gradual abandonment of "steam" plants in favor of the cells, with the eventual biological breakthrough merely serving to seal the coffin.
So the production of plentiful methane and ethanol from biomass, coupled with massive investment in the process of harvesting hydrogen from these sources, provides an initial impetus to the conversion to hydrogen infrastructure. At Neil Armstrong Intercontinental Airport, the majority of hydrogen is produced through boosted electrolysis that relies on the bio-solar process. Recent introductions of proprietary bacterial strains from a Brazil research laboratory have bumped up efficiency another 2.2 percent.
The result of a whole century of development and energy evolution is plentiful energy for the foreseeable future but at significant cost to users as the enormous capital investment in infrastructure cannot be recovered until 2140 at the earliest. And who knows what new investments may yet be needed?
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