More on energy and getting SPS into GEO
Energy is a relative thing, the difference between high pressure and lower pressure, the difference between hot and colder, between fast and slower. Energy is the ability to do work. Forces of the natural world that we harvest, harness to do our work for us; as we direct its changes from a higher form to a lower form, getting our task done along the way.
The creation of a windmill has much in common with creating Solar Power Satellites in GEO.
So for an analogous example, to convert wind energy we need to do all necessary to create a windmill at an appropriate location, and connect it to the electric power grid; anchored to the mass of the the earth, the windmill's blades drag against the fast moving air pathway, slowing the air a bit while converting that wind movement redirected to electrical energy increase.
It takes thought and energy and materials (and human physical activity) to create the windmill, and generally the amount of energy extracted and input to the power grid needs to be far more than the sum energy used to create the windmill there. To some extent this energy can be equated to monetary terms, but the complications of human involvements in the processes of creating the on-site windmill weigh heavily on those monetary descriptions.
The vast collections of ideas humanity has compiled thru history (each idea hard-won originally) is the instrument of thought that provides the patterns for human activity in the creation of the windmill or whatever the device contrived to get out work done by the forces of nature. Given somehow the unified activity of people sufficient to get the project going and done, more energy (and perhaps other involvement usefulness) needs be gotten out of the result, than is put into its original creation.
Thus the chemical fueled reaction engine propulsion for ground to space access technique we have used exclusively so far for space activity, the energy of fuel to lift from ground to GEO far exceeds the energy expectable from SPS in GEO, especially considering energy used to build the launch vehicle and infrastructure, as well as in the building of the parts for the SPS. This is why the mid-1970's approach of building SSPS at L5 (equidistant from the Moon and the Earth) out of lunar materials by people living in Stanford Torus type cities in L5, was conceived.
We were on a roll then, routinely landing Apollos on the lunar surface; those who foresaw our need for clean electrical abundant energy delivered worldwide by SPS built there, forgot that the reason we were landing on the Moon was not to prepare the way for civilization's future success through space resources, but instead to block a rival nation from building missile launch stations on the Moon, rivals who had attempted to do that in Cuba recently at the time, and next were aimed at getting to the Moon. When war threats were sufficiently prevented by our Apollo project, having won the "space race", Apollo dried up and so went the dreams of SPS built in L5 out of Lunar materials.
Three decades later, the energy crisis has overtaken us now, and we still struggle to find ways for chemical propelled rockets to be used (since that is a technology we know how to use well, and businesses are set up to do that abundantly) to put SPS into GEO, maybe gossamer-thin SPS lifted on big dumb rockets; or even build them on the Moon mostly out of Lunar materials, and beam energy at the Earth's rectenna power receivers from there: still trying to do it the old way, or so it seems.
Thoughts of other means for lifting up there have sloshed around in mankind's thinking mill, now more driven by the hungers of stomach and egos in the raised awareness we need clean energy more, and maybe it is getting serious?
Jeers at ideas of Earth-rotatated counterweight supported anchored tether space elevators made of "Unobtanium," have given way to consideration of carbon fiber derived tethers of constant stress cross-section, something to climb up and down upon; and if a high enough strength to mass ratio tether material is created, then true counterbalanced elevator car lift is conceivable, the tether ribbons slung between pulleys located at ground and above GEO.
Another kind of ground to GEO access structure is also conceivable, a structure that fully encircles the Earth and is whirling around the planet so fast that its outward centrifugal force counterbalances the weight of the parts of the structure that are not whirling. Its path would resemble an orbital transfer trajectory ellipse between earth surface on the equator, up around to a high point above the opposite side of the planet at GEO altitude. Some of the kinetic energy of that circulating high velocity mass stream that is moving upward, could be used via electrodynamic braking upward to lift the vehicles up the structure to GEO. All electric, this transportation technique could eventually be sustained by some of the SPS electrical power it enables built in GEO.
So, some potentially adequate techniques for lifting SPS constructions materials from ground to GEO exist in the thought base of civilization.
As to whether or not SPS get built there, depends on the comprehension that survival of America depends not on just keeping the rival's rocket nukes off the moon, but instead in the providing of environmentally clean adequate power to America and indeed the whole world, to throttle down the greenhouse gas bringing on cascade failure of the world environment. Will this comprehension exceed the inertia of industry and business? No sign of it happening so far. Even the potentials of the anchored tether space elevator and/or that of the carousel space escalator concepts represent aerospace corporations being aced out by the elevator/escalator concept becoming "the only game in town" thus is an unacceptable thing in the eyes of those who are rich and powerful enough to make these things happen: a "catch 22" kind of thing that probably is already too late to save the world ecosystem if the recent analysis by the scientist James Lovelock, originator of the term "Gaia", the world's unified living entity, is correct "(Lovelock: The Point of No Return is Behind Us.")
The shakers & movers of this nation did not take on the Apollo project to save civilization's future, they did it for self preservation from a human threat; and they still cannot conceive of threat to their supportive system as being of nature's needs for survival along with their own, thus nothing gets done to preserve civilization this way. We need to have multi-focused paths for survival, certainly, including the creation of ways to harness land-accessible forms of extracting solar-originated energy of wind and water and direct sunlight; and carefully of nuclear energy. The well being of general mankind may well be dependent on them getting those who have focused on personal power to find ways to make the fastest megabuck while lolling around in luxury unimaginable by most of us. Can we get their attention enough to be responsible to civilization, a somewhat different focus than making money and playing the ego power games?
Even the corporate kind of "entity" has the form of snobbery called the "NIH" (the "Not Invented Here" syndrome), that interferes with the wisest selection of ideas which pattern possibilities. Much of the managerial leadership is driven by climbing around in the org chart, the hierarchy of people, instead of technological arenas of energy and resources and human consumption, other than considering them as forces of motivation sources of their income and social delights.
It may come down to the old problem of how the people can get the bully mentalities which cleverly grabbed leadership over them, to pause enough from battle's excitements of board room and elsewhere, to much more responsibly lead them all into better survival and even plentifulness? It is likely that such people don't actually "see" the environment they crush, seeing only people as significant items in the world. Felling the opponent, rewarding the ally, and the goodies all default into the winner's hands. To get their assistance in saving the world, somehow the task needs be put into terms of which they can be aware. Put the task into terms of people, not in terms of the vaster natural world of which people are only parts, yet which make in aggregate such major impact.
Again, some potentially adequate techniques for lifting SPS constructions materials from ground to GEO already do exist in the thought base of civilization, and are ready for serious R&D. That is not the major problem.
by Jim Cline on 20060725