Space-based. Solar power SB SP is the concept, of collecting, solar power in outer space and distributing. It to earth. Potential. Advantages, of collecting, solar energy, in space include, a higher collection, rate in a longer collection, period due to the lack of a diffusing atmosphere, and the possibility, of placing a solar collector in, an orbiting, location, where there is no night a, considerable. Fraction of incoming solar energy, 55, to 60 percent is lost on its way through the Earth's atmosphere by, the effects, of reflection, and absorption. Space-based. Solar power systems, convert sunlight to, microwaves, outside, the atmosphere avoiding. These losses in the downtime due to the Earth's rotation but, at great cost due to the expense of, launching, material, into orbit, SB. SP is considered, a form of sustainable. Or green energy. Renewable energy. And is occasionally, considered, among climate engineering proposals. It. Is attractive, to those seeking large-scale, solutions, to anthropogenic, climate change or fossil fuel depletion such, as Peak Oil. Various. SPSP, proposals, have been researched, since the early 1970s. But none are economically, viable with present-day, space, launch infrastructure. A modest. Gigawatt, range microwave, system, comparable, to a large commercial, power plant would require launching, some 80,000. Tons of material, to orbit making, the cost of energy from such a system, vastly, more expensive, than even present-day renewable, energy, some. Technologists. Speculate, that this may change in the distant future if, an offworld industrial, base were to be developed that could manufacture solar, power satellites, out of asteroids, or lunar material, or if radical, new space launch technologies. Other than rocketry, should become available in, the future, besides. The cost of implementing, such a system, SB SP also introduces. Several technological, hurdles. Including the problem of transmitting, energy from orbit to Earth's surface for, use, since. Y is extending. From Earth's surface to an orbiting satellite and, neither practical nor feasible. With current technology, SB, SP designs generally, include the use of some manner of wireless power transmission, with its concomitant conversion. Efficiency, as, well as land-use, concerns, for the necessary antenna, stations to, receive the energy at Earth's surface, the. Collecting, satellite, would convert solar energy into, electrical, energy on board powering, a microwave, transmitter, or laser emitter, and transmit, this energy, to a collector, or microwave, retina on Earth's surface. Contrary. To appearances of, SPSP, in popular, novels and video games most designs, propose, beam energy densities, that are not harmful if human beings were to be inadvertently exposed, such. As if a transmitting, satellites, beam were to wander off course, but. The vast size of the receiving, antennas, that would be necessary would, still require large, blocks of land near the end users to be procured and dedicated, to this purpose, the. Service, life of space-based, collectors, in the face of challenges, from long-term exposure, to the space environment including. Degradation from, radiation, and micrometeoroid. Damage could, also become a concern, for Espie Espie Espie. Espie. Is, being actively pursued by Japan China and Russia in. 2008. Japan passed, its basic, space law which established, space solar power as a national, goal in Jay AXA, has a roadmap, to commercial, SPSP, in 2015. The China Academy, for space technology cast. Showcased. Their roadmap at, the international, space development, conference. Topic. History. In. 1941. Science. Fiction writer Isaac Asimov, published, the science fiction short story reason. In, which a space station transmits, energy, collected, from the Sun to various, planets, using microwave, beams, the. SB SP concept, originally, known as satellite. Solar power system, SSPs. Was first described, in November, 1968. In. 1973. Peter Glazer was granted, US patent, number 3 million, 780. 1647, for his method of transmitting, power over, long distances, eg, from an SPS, to Earth's surface using. Microwaves, from a very large antenna, up to one square kilometer, on the satellite, to a much larger one now known as a rec tena on the ground laser then was a vice president, at Arthur D little Inc. NASA. Signed, a contract, with ADL, to lead for other companies, in a broader study in, 1974. They. Found that while the concept, had several, major problems, chiefly, the expense, of putting the required materials, in orbit and the lack of experience on projects, of this scale in, space it showed enough promise to, merit further investigation. And research between, 1978.
And 1986, the Congress, authorized, the Department, of Energy DOE and NASA to jointly, investigate. The concept, they. Organized, the satellite, power system, concept, development, and evaluation, program the, study remains, the most extensive. Performed, to date budget, fifty million dollars. Several. Reports, were published investigating. The engineering, feasibility. Of such an engineering, project. They. Include. Resource. Requirements. Critical, materials, energy, and land. Financial. Management, scenarios. Public. Acceptance. State. And local regulations. Is applied to satellite, power system, microwave, receiving, antenna facilities. Student. Participation. Of laser for SPSP, power transmission. International. Agreements. Centralization. Decentralization. Mapping. Of exclusion, areas for rectina sites. Economic. And demographic issues. Related, to deployment. Some. Questions, and answers. Meteorological. Effects. On laser beam propagation, and direct solar pump lasers. Public. Outreach experiment. Power. Transmission. And reception technical. Summary and assessment. Space. Transportation. Topic. Discontinuation. The, project, was not continued, with the change in administration's. After the 1980, US Federal Elections the. Office of Technology, Assessment concluded. That too, little is currently, known about the technical, economic. And environmental. Aspects, of SPS, to make a sound decision whether to proceed with its development, and deployment. In. Addition. Without further, research, in SPS, demonstration. Or systems, engineering, verification. Program would be a high-risk venture. In. 1997. NASA conducted its, freshlook. Study. To examine the modern state of SPSP, feasibility. In. Assessing. What, has changed, since. The DOE study NASA, asserted, that the US, National Space, policy now, calls for NASA to make significant. Investments, in technology not. A particular, vehicle, to drive the costs of at of2, orbit, transportation. Down dramatically. This. Is of course an absolute. Requirement of, space solar power. Conversely. Dr., Pete worden of NASA claimed that space-based, solar is about five orders of magnitude more expensive. Than solar power from the Arizona, desert with a major cost being the transportation. Of materials to orbit, dr.. Worden referred to possible, solutions, as speculative, and which would not be available for, decades at the earliest on November, 2nd 2012, China proposed, space collaboration. With India that mentioned, SPSP, maybe. Space-based. Solar power, initiative, so that both India, and China can, work for long term association. With proper funding along with other willing spacefaring. Nations, to bring space solar power to earth, in. February, 20 nineteen teens. To. Build power satellites. Topic. Space. Solar power exploratory. Research and, technology. Program. In, 1999. NASA's, space solar power exploratory. Research and, technology, program cert, was initiated. For the following purposes. Perform. Design studies, of selected, flight demonstration. Concepts. Evaluate. Studies of the general feasibility. Design, and requirements. Create. Conceptual. Designs, of subsystems, that make use of advanced, SSP, technologies. To benefit, future space or terrestrial applications. Formulate. A preliminary, plan of action for the u.s. working with international, partners to undertake, an aggressive, technology, initiative. Construct. Technology, development, and demonstration roadmaps. For critical, space solar power SSP, elements, cert went about developing a solar power satellite, SPS, concept, for a future gigawatt, space power system, to provide electrical, power by, converting, the sun's energy and beaming, it to Earth's surface and provided, a conceptual, development path, that would utilize current.
Technologies. Surt, proposed, an inflatable, photovoltaic, gossamer. Structure, with concentrator. Lenses, or solar heat engines, to convert sunlight into electricity. The. Program, looked both at systems, in Sun synchronous orbit, and geosynchronous, orbit. Some. Of se artis conclusions. The. Increasing, global energy demand is, likely to continue for many decades resulting. In new power plants, of all sizes being, built. The. Environmental. Impact of those plants, and their impact on world energy, supplies and geopolitical. Relationships. Can be problematic. Renewable. Energy is a compelling, approach, both philosophically. And in engineering terms. Many. Renewable, energy sources are limited in their ability to affordably. Provide, the base load power required, for global, industrial, development, and prosperity because. Of inherent land, and water requirements. Based. On their concept, definition study. Space, solar power concepts. May be ready to re-enter the discussion. Solar. Power satellites, should no longer be envisioned, as requiring unimaginably. Large initial, investments. In fixed infrastructure, before the emplacement, of power, plants, can begin. Space. Solar power systems, appear to possess many, significant. Environmental, advantages. When compared, to alternative. Approaches. The. Economic, viability of, space solar power systems, depends, on many factors in, the successful, development of various new technologies, not least of which is the availability, of much lower cost access to space than has been available however the, same can be said of many other advanced, power technologies. Options. Space. Solar power may well emerge as a serious, candidate, among the options for meeting the energy demands, of the 21st century. Space. Solar power satellite, technology. Development, at the Glenn Research Center an, overview. James. II Duden Hofer and Patrick J George NASA Glenn Research Center Cleveland. Ohio. Launch. Costs, in the range of $100. To $200. Per kilogram, of payload, from low Earth orbit, to geosynchronous, orbit. Are needed if SPS, is to be economically, viable. Topic. Japan, aerospace exploration. Agency. The, May 2014, I Tripoli spectrum, magazine, carried a lengthy article it's, always, sunny in space. By. Dr., Seuss uma Sasaki the article. Stated, it's, been the subject of many previous studies, and the stuff of sci-fi for decades, but space-based, solar power could at last become, a reality and, within. 25. Years according. To a proposal, from researchers, at the Tokyo, based Japan, aerospace exploration. Agency. Jay AXA. Jay. AXA, announced, on the 12th of March 2015, that they wirelessly, beamed 1.8. Kilowatts, 50 meters to a small receiver by converting electricity, to microwaves, and then back to electricity. This. Is the standard, plan for this type of power on the 12th, of March 2015. Mitsubishi Heavy, Industries, demonstrated. Transmission, of 10 kilowatts, kW of, power to, a receiver, unit, located at a distance of 500 meters, M away. Topic. Challenges. Topic. Potential. The, SPSP concept, is attractive, because space has several major advantages. Over the Earth's surface for, the collection, of solar power, it. Is always solar noon in space and full Sun. Collecting. Surfaces, could receive much more intense, sunlight owing, to the lack of obstructions. Such as atmospheric gases. Clouds, dust, and other weather events. Consequently. The intensity. In orbit is approximately. One hundred and forty-four percent of the maximum attainable intensity. On Earth's surface a. Satellite. Could be illuminated. Over 99%. Of the time and be in Earth's shadow a maximum, of only 72. Minutes per night at the spring and fall equinoxes. At local midnight. Orbiting. Satellites, can be exposed, to a consistently. High degree, of solar radiation generally. For 24, hours per day whereas, Earth's surface solar, panels, currently, collect power for an average of 29%. Of the day, power. Could be relatively, quickly redirected. Directly, to areas that need it most a. Collecting. Satellite, could possibly, direct power on demand to different surface locations, based on geographical. Base load or peak load power needs. Typical. Contracts, would be for base load continuous.
Power Since, peaking power is ephemeral. Elimination. Of plant and wildlife interference. With. Very large-scale, implementations. Especially. At lower altitudes, it potentially, can reduce incoming, solar radiation reaching, Earth's surface. This. Would be desirable for counteracting the effects of global warming. Topic. All backs. The. SPSP, concept, also has a number of problems. The. Large cost of launching, a satellite into, space. The. Thinned array curse preventing, efficient, transmission, of power from space to the Earth's surface. Inaccessibility. Maintenance. Of an earth-based solar panel, is relatively, simple but construction and maintenance on, a solar panel in space would typically be done tele robotically. In. Addition, to cost astronauts. Working in geo geosynchronous. Earth orbit, are exposed, to unacceptably. High radiation, dangers, and risk and cost about 1,000, times more than the same task done tele robotically. The. Space environment, is hostile, panels, suffer about eight times the degradation they, would on earth except, at orbits that are protected, by the magnetosphere. Space. Debris is a major hazard to large objects, in space and all large structures, such as SPSP. Systems, have been mentioned, as potential, sources of orbital, debris, the. Broadcast, frequency. Of the microwave, downlink, if used would require isolating. The SP SP systems, away from other satellites. Geo. Space, is already well, used and it is considered, unlikely the ITU, would allow an SPS, to be launched. The. Large size and corresponding. Cost of the receiving, station on the ground. Energy. Losses during several phases of conversion, from photons, to electrons, two photons, back to electrons. Design. Space-based. Solar power essentially, consists, of three element. Collecting. Solar energy, in space with reflectors, or inflatable mirrors, onto solar cells. Wireless. Power transmission, to earth via microwave, or laser. Receiving. Power on earth via, retina, a microwave, antennas, space-based, portion, will not need to support itself against, gravity, other than relatively, weak tidal, stresses, it. Needs no protection, from terrestrial wind, or weather but will have to cope with space, hazards, such as micro, meteors, and solar flares. Two. Basic methods of conversion, have been studied, photovoltaic, PV, and solar dynamic, SD, most. Analyses, of SPSP. Have focused, on photovoltaic, conversion, using. Solar cells that directly, convert sunlight into electricity. Solar. Dynamic, uses mirrors to concentrate light. On a boiler, the, use of solar dynamic, could reduce mass per watt wireless. Power transmission. Was proposed early on as a means to transfer, energy from collection, to the Earth's surface using. Either microwave, or laser radiation, at a variety of frequencies. Topic. Microwave. Power transmission. William. C Brown demonstrated. In 1964. During Walter, Cronkite CBS, news program, a microwave, powered, model helicopter, that received all the power it needed for flight from a microwave, beam, between. 1969. And, 1975. Bill brown was technical, director, of a JPL, Raytheon, program, that beamed 30 kilowatts, of power over, a distance of 1 mile 1.6, kilometers. At, 84, percent efficiency. Microwave. Power transmission. Of tens of kilowatts has been well proven by existing, tests at Goldstone in California. 1975. And grand Bassin on Reunion Island. 1997. More. Recently, microwave. Power transmission. Has been demonstrated. In conjunction, with solar energy capture. Between a mountaintop, in Maui in the island of hawaii 92. Miles away by a team under john c Mankins. Technological. Challenges, in terms of array layout single, radiation, element design and overall efficiency as. Well as the associated, theoretical. Limits are presently a subject, of research as, it was demonstrated, by the special, session on analysis, of electromagnetic. Wireless. Systems, for solar power transmission. Held. During the 2010, I Triple, E symposium. On antennas, and propagation, in. 2013. A useful, overview was published, covering, technologies. And issues associated with, microwave. Power transmission. From space to ground it. Includes, an introduction, to SPS, current, research and future prospects. Moreover. A review, of current methodologies. And technologies for, the design of antenna arrays for microwave, power transmission.
Appeared In the Proceedings, of the IEEE Tripoli. Topic. Laser, power, beaming. Laser, power, beaming was envisioned by some at NASA as a stepping, stone to further industrialization. Of space in. The 1980s. Researchers. At NASA worked on the potential, use of lasers, for space to space power beaming focusing, primarily on, the development, of a solar-powered laser, in. 1989. It was suggested that power could also be usefully, beamed by laser from earth to space in. 1991. The Saleen project, space laser energy, had begun which included, the study of laser power beaming for supplying power to a lunar base the. Selene program, was a two-year, research effort but the cost of taking the concept to operational. Status was, too high and the official, project ended, in 1993. Before reaching a space-based, demonstration. In 1988. The use of an earth-based laser to power an electric thruster. For space propulsion was proposed, by grant Logan, with technical, details worked out in 1989. He. Proposed, using, diamonds solar cells operating, at 600, degrees to convert ultraviolet. Laser light. Topic. Orbital. Location. The. Main advantage, of locating, a space power station, in geostationary. Orbit, is that the antenna geometry, stays constant, and so keeping the antennas, lined up is simpler, another. Advantage, is that nearly continuous. Power transmission. Is immediately, available as, soon as the first space power station, is placed in orbit other space-based, power, stations, have much longer startup, times before, they are producing, nearly continuous. Power a collection. Of Leo low-earth, orbit, space power stations, has been proposed, as a precursor, to geo geostationary. Orbit, space-based. Solar power. Earth-based. Receiver. The. Earth-based, rectina, would likely consists, of many short dipole antennas, connected via diodes. Microwave. Broadcasts. From the satellite, would be received in the dipoles, with about 85%, efficiency. With. A conventional, microwave. Antenna, the reception efficiency. Is better but its cost and complexity, are also considerably. Greater, rec. Tenors would likely be several, kilometers across. Topic. In space, applications. The. Laser SP SP could also power a vase or vehicles, on the surface, of the Moon or Mars saving. On mass costs, to land the power source, a spacecraft. Or another satellite, could also be powered by the same means, in. A 2012, report presented. To NASA on space solar power the author mentions, another potential. Use for the technology behind space, solar power could be for solar electric, propulsion systems, that, could be used for interplanetary, human. Exploration missions. Topic. Launched costs. One problem for the SPSP, concept, is the cost of space launches, and the amount of material, that would need to be launched. Much. Of the material launch, need not be delivered to its eventual orbit, immediately which. Raises the possibility that, high efficiency, but slower engines, could move SPS, material, from Leo to Geo at an acceptable, cost. Examples. Include ion, thrusters, or nuclear, propulsion power. Beaming from geostationary. Orbit, by microwaves, carries, the difficulty, that the required optical, aperture, sizes are very large, for. Example the. 1978. Nasser SPS, study required, a one kilometer diameter, transmitting. Antenna and the 10 kilometers, diameter, receiving, rectina for a microwave, beam at 2.45. Gigahertz. These. Sizes, can be somewhat, decreased by using shorter, wavelengths, although they have increased atmospheric absorption, and, even potential, beam blockage, by rain or water droplets. Because. Of the thinned array purse it is not possible, to make a narrow beam by combining, the beams of several, smaller satellites. The. Large size of the transmitting, and receiving antennas. Means that the minimum practical, power level for an SPS, will necessarily be, high small, SPS, systems, will be possible, but uh neck anomic, to give an idea of the scale of the problem, assuming, a solar panel mass of 20 kilograms, per kilowatt, without considering, the mass of the supporting, structure, antenna, for any significant. Mass reduction of any focusing, mirrors a full gigawatts, power station, would weigh about 80,000. Metric tons all of which would in current circumstances. Be launched from the earth very. Lightweight designs, could likely achieve, one kilogram per kilowatt, meaning, four thousand, metric tons for, the solar panels, for the same four gigawatts, capacity, station, this. Would be the equivalent of between 40, and 150. Heavy lift launch vehicle HL, LV launches, to send the material, to low-earth orbit, where it would likely be converted, into sub assembly solar arrays which then could use high-efficiency, ion, engines style rockets to slowly reach geo geostationary. Orbit, with. An estimated, cereal, launch cost for shuttle based, I ll v's of 500 million dollars to 800 million dollars, and launch costs, for alternative, HL LVS at 78, million dollars total launch, costs, would range between 11, billion dollars low, cost HL, LV low weight panels and 320.
Billion Dollars expensive. HL LV heavier, panels, to. These costs, must be added the environmental. Impact of heavy space launch missions, if such costs, are to be used in comparison. To earth-based, energy, production, for. Comparison. The direct, cost of a new coal or nuclear power, plant ranges, from three billion dollars, to six billion dollars, per gigawatt not including, the full cost to the environment from, co2 emissions, or storage, of spent nuclear fuel, respectively. Another example, is the Apollo missions, to the moon cost a grand total of twenty four billion dollars, 1970s. Dollars taking, inflation into account would, cost one hundred and forty billion dollars today more expensive, than the construction, of the International, Space Station. Topic. Building. From space. You. Topic. From, lunar, materials. Launched, in orbit. Gerard. O'Neill noting. The problem of high launch costs, in the early 1970s. Proposed. Building, the SPS is in orbit with materials, from the moon launch. Costs, from the moon are potentially, much lower than from Earth due to the lower gravity, and lack of atmospheric, drag this. 1970s. Proposal, assumed the then advertised, future, launch costing, of NASA's Space Shuttle, this. Approach would require substantial, upfront. Capital investment. To establish, mass drivers, on the moon, nevertheless. On, the 30th, of April 1979. The, final report lunar. Resources. Utilization. For space construction. By. General, Dynamics convair, division, under NASA contract, na s nine - fifteen thousand. 560. Concluded. That use of lunar resources, would be cheaper than earth-based, materials. For a system, of as few as 30 solar power satellites, of 10 gigawatts capacity. Each in 1980. When it became obvious NASA's. Launch cost estimates, for the Space Shuttle were, grossly optimistic. Only al published, another route to manufacturing. Using lunar, materials, with much lower start-up, costs, this. 1980s. SPS, concept, relied less on human presence in space and, more on partially, self-replicating. Systems, on the lunar surface and, a remote control of, workers, stationed, on earth the. High net energy gain of this proposal, derives, from the moon's much shallower gravitational. Well. Having. A relatively, cheap per pound source of raw materials, from space would lessen the concern, for low mass designs, and result in a different sort of SPS, being built, the. Low cost per pound of lunar materials, in O'Neill's vision would be supported, by using lunar material, to manufacture. More facilities. In orbit than just solar power satellites. Advanced. Techniques, for launching, from the moon may reduce the cost of building a solar power satellite, from lunar materials.
Some. Proposed techniques, include, the lunar mass driver in the lunar space elevator, first, described, by Jerome Pearson it would require establishing. Silicon, mining and solar cell manufacturing, facilities, on the moon. Topic. On the, moon. Physicist. Dr. David, Cresswell suggests. The moon is the optimum, location for solar power stations, and promotes, Luna based solar power the main, advantage, he envisions, is construction. Largely from locally, available lunar. Materials, using, in situ resource utilization, with. A teleoperated. Mobile, Factory, in crane to assemble the microwave, reflectors, and Rovers, to assemble, and pave solar cells which would significantly reduce, launch, costs, compared to SB SP designs. Power. Relay, satellites, orbiting, around Earth in the moon reflecting, the microwave, beam are also part, of the project a demo. Project, of one gigawatt starts, at fifty billion dollars, the. Shimizu corporation. Used combination, of lasers and microwave, for the lunar ring concept, along with power relay, satellites. Topic. From an asteroid. Asteroid. Mining has also been seriously. Considered, and NASA design, study evaluated. A 10,000, ton mining, vehicle, to be assembled, in orbit that would return a 500,000. Ton asteroid, fragment, to geostationary. Orbit. Only. About 3,000. Tons of the mining ship would be traditional aerospace-grade. Payload. The. Rest would be reaction. Mass for the mass driver engine, which could be arranged to be the spent rocket stages, used, to launch the payload. Assuming. That 100 percent of the returned asteroid, was useful, and that the asteroid miner itself, couldn't be reused that represents, nearly a 95, percent reduction. In launch costs. However. The, true merits of such a method would depend on a thorough mineral, survey of the candidate, asteroids, thus far we have only estimates, of the composition. One. Proposal, is to capture the asteroid, Apophis into, Earth orbit and convert, it into 150. Solar, power satellites, of 5 gigawatts each or the larger asteroid, 1999. A and 10 which is 50 X the size of APIs, and large enough to build. 7500. 5 gigawatt, solar power satellites. Topic. Gallery. Topic. Counter-arguments. You. Topic. Safety. The. Use of microwave transmission. Of power has been the most controversial, issue in considering, any SPS, design, at. The Earth's surface a suggestive microwave, beam would have a maximum intensity. At its center of 23. Millivolts, per square centimeter, less than 1/4 the solar irradiation, constant. And an intensity, of less than 1 milli watt per square centimeter, outside, the rectina fence line the receivers, perimeter, these. Compared, with current United States Occupational. Safety and Health Act OSHA workplace. Exposure, limits, for microwaves, which are 10 milli watts per square centimetre, the limit itself being expressed, in voluntary, terms and ruled unenforceable. For federal osha enforcement. Purposes, a beam. Of this intensity, is therefore, at its center over similar magnitude to, current safe workplace, levels, even for long term or indefinite, exposure, outside. The receiver it is far less than the OSHA long term levels over 95%, of, the beam energy will fall on the retina the.
Remaining, Microwave, energy will be absorbed and dispersed, well within standards, currently imposed. Upon microwave. Emissions around the world it. Is important, for system efficiency, that as much of the microwave, radiation as possible be focused, on the retina. Outside. The retina microwave, intensities. Rapidly, decrease so nearby towns or other human activity, should be completely, unaffected exposure. To the beam is able to be minimized, in other ways on the. Ground physical, access is controllable, eg, via fencing, and typical, aircraft flying, through the beam provide, passengers, with a protective metal, shell ie a Faraday, cage which, will intercept, the microwaves. Other. Aircraft, balloons, ultralight, etc. Can avoid exposure, by observing air flight control, spaces, as is currently done for military and other controlled, airspace, the. Microwave, beam intensity, at ground level in the center of the beam would be designed and physically, built into the system simply. The transmitter, would be too far away and too small, to be able to increase the intensity to, unsafe, levels even in principle. In addition, a design, constraint, is that the microwave, beam must not be so intense as to injure wildlife, particularly, Birds. Experiments. With deliberate, microwave, irradiation at. Reasonable, levels have failed to show negative effects, even over multiple, generations. Suggestions. Have been made to locate rec tenors offshore but this presents serious, problems, including. Corrosion, mechanical, stresses and biological. Contamination, a, commonly. Proposed, approach to ensuring, failsafe beam, targeting, is to use a retro, directive, phased array antenna, rectina, a. Pilot. Microwave. Beam emitted from the center of the retina on the ground establishes. A face front of the transmitting, antenna, their. Circuits. In each of the antennas sub-arrays, compare, the pilot beams phase front with an internal clock phase to control the phase of the outgoing signal. This. Forces the transmitted. Beam to be centered precisely, on the retina and to have a high degree of phase uniformity. If the pilot beam is lost for any reason, if the transmitting, antenna is turned away from the retina, for example, the phase control, value fails and the microwave, power beam is automatically, defocused. Such. A system, would be physically, incapable of, focusing, its power beam anywhere, that did not have a pilot, beam transmitter. The. Long-term effects, of beaming power through the ionosphere in, the form of microwaves, has yet to be studied but nothing has been suggested, which might lead to any significant. Effect. Topic. Timeline. You. Topic. In the, 20th century. 19:41. Isaac asimov published the science fiction short story, reason. In, which a space station transmits, energy, collected. From the Sun to various, planets, using microwave, beams. 1968. Dr. Peter Glazer introduces. The concept of, a solar, power satellite. System. With square miles of solar collectors in, high geosynchronous. Orbit, for collection, and conversion, of sun's energy into, a microwave, beam to transmit, usable energy to large receiving. Antennas, rec tenders on earth for distribution. 1973. Dr., Peter Glaser is granted, United, States patent number 3 million 780. 1647. For his method of transmitting, power over long distances, using microwaves, from a large 1 square kilometer antenna, on the satellite, to a much larger one on the ground now known as a rec tenner.
1978. To 81, the united, states department of, energy and nasa examined. The solar power satellite, SPS, concept, extensively. Publishing. Design and feasibility, studies. 1987. Stationary. High-altitude relay, platform, a Canadian, experiment. 1995. To 97, NASA conductor. Freshlook. Study. Of space solar power SSP. Concepts. And technologies. 1998. The space solar power concept, definition study, CDs identifies. Credible, commercially. Viable SSP. Concepts, while pointing out technical, and programmatic risks. 1998. Japan, Space Agency, begins developing, a space solar power system, SSPs. A program, that continues to the present day. 1999. NASA's space solar power exploratory. Research and, technology, program cert, Cibolo. Begins. 2000. John Mankins, of nasa testifies. In the US House of Representatives saying. Large-scale. SSP, is a very complex, integrated, system, of systems that requires numerous significant. Advances, in current, technology, and capabilities. A. Technology. Roadmap, has been developed, that lays out potential, paths for achieving all needed advances, will, be it over several decades. Topic. In the 21st, century. 2001. NASD. A one, of Japan's national, space agencies, before it became part of jxa, announces, plans to perform additional research, and prototyping. By launching an experimental. Satellite, with 10 kilowatts, and 1 megawatt of power. 2003. ESA, studies. 2007. The US Pentagon's, national, security, space office, NSSO. Issues, a report on October, 10th, 2007. Stating, they intend to collect solar energy, from space for use on earth to help the United, States ongoing, relationship, with the Middle East and the battle for oil a demo. Plant could cost 10 billion dollars produce, 10 megawatts, and become, operational, in 10 years. 2007. In May, 2007. A workshop, is held at the u.s. Massachusetts. Institute of, Technology MIT, to. Review the current state of the SPSP, market, and technology. 2010. Professors, Andrea Mathur and Giorgio francesca, T announced a special session on the analysis. Of electromagnetic. Wireless, systems, for solar power transmission. At, the 2010, Institute, of Electrical and, Electronics, Engineers, international. Symposium, on antennas, and propagation. 2010. The Indian Space Research, Organisation. And US National, Space Society launched. A joint forum. To enhance partnership. In harnessing, solar energy, through space-based, solar collectors. Called. The Kalam NSS, initiative, after the former Indian president dr., APJ Abdul, Kalam the, forum will lay the groundwork for the space-based, solar power program, which could see other countries joining, in as well. 2010. Skies, No Limit space-based. Solar power the next major step in the Indo us strategic, partnership, written, by USAF. Leftenant, Col Peter Garretson was published, at the Institute, for Defense studies, and analysis. 2012. China proposed, joint development between, India and China towards. Developing, a solar power satellite, during a visit by former, Indian president dr., APJ Abdul. Kalam. 2015. The space solar power initiative, SSPI. Is established, between Caltech. And Northrop, Grumman Corporation an. Estimated. Seventeen, point five million dollars, is to be provided, over a three-year project for, development, of a space-based solar, power system. 2015. J AXA, announced, on the 12th of March 2015, that they wirelessly, beamed 1.8. Kilowatts, 50 meters to a small receiver by converting, electricity, to microwaves, and then back to electricity. 2016. Leftenant, general, jiang Yulin deputy, chief of the flower armament development, department, of the Central Military Commission suggested. That, China would next begin to exploit earth-moon, space for industrial, development, the. Goal would be the construction, of space-based, solar power satellites, that would be menergy back to earth. 2016. 13, with membership from the Naval Research Laboratory, NRL. Defense, Advanced Projects, Agency dar. PA Air Force Air University. Joint staff logistics, j4, Department. Of State Macon's, aerospace, and Northrop Grumman won the Secretary, of Defense, SecDef. Secretary. Of State sec, sta t usaid. Director's, agency-wide. E3, diplomacy. Development defense. Innovation, Challenge with a proposal, that the US must lead in space solar power the, proposal. Was followed by a vision, video. 2016. Citizens. For space-based, solar power has transformed, the d3, proposal, into active petitions, on the White House website, America. Must lead the transition, to space-based, energy, and, change.org. USA. Must lead the transition to space-based, energy. Along. With the following video. 2016. Erik, Larsen and others from NOAA, producer. Paper global. Atmospheric. Response to emissions, from a proposed, reusable.
Space Launch system. The. Paper makes a case that up to two terawatts, per year of power satellites, could be constructed, without intolerable. Damage to the atmosphere, before. This paper, was concerned, that the NOx produced, by reentry, would destroy too much ozone. 2016. Ian's cache of SIAC proposes. Cassiopeia, constant, aperture solid-state. Integrated. Orbital, phased array a new concept, SPS, 1. 2017. NASA, selects, five new research proposals, focused, on investments. In space, the. Colorado, School of Mines focuses. On 21st, century trends, in space-based, solar power generation, and storage. Topic. Non typical configurations. And architectural. Considerations. The typical, reference system, of systems involves. A significant, number several, thousand, multi gigawatt, systems, to service all or a significant. Portion of Earth's energy requirements. Of individual, satellites, in geo the. Typical, reference, design for the individual, satellite, is in the 1 to 10 gigawatts range, and usually involves, planar or concentrated. Solar photovoltaics, PV. As the energy collector conversion. The. Most typical transmission. Designs are in the 1 to 10 gigahertz. 2.45. Or 5.8. Gigahertz RF, band where there are minimum losses in the atmosphere. Materials. For the satellites, are sourced from and manufactured. On earth and expected, to be transported. To Leo via reusable. Rocket launch and transported. Between Leo and geo via chemical, or electrical propulsion. In. Summary, the architecture. Choices, are location. Equals geo energy, collection equals, TV satellite equals, monolithic, structure, transmission, equals RF materials, and manufacturing equals. Earth installation. Equals our LVS Tullio chemical, 2 geo therea several, interesting, design variants, from the reference system alternate. Energy collection location. While geo is most typical, because of its advantages, of nearness to earth simplified. Pointing, and tracking, very small time in occultation and scalability. To meet all global demands several, times over other locations, have been proposed, some fl1, Robert Kennedy the 3rd Ken Roy and David fields have proposed a variant, of the l1 sunshade. Called Dyson, dots where a multi terawatt, primary, collector, would beam energy, back to a series, of Leo's sun-synchronous, receiver. Satellites. The. Much farther distance, to earth requires, a correspondingly. Larger, transmission, aperture. Lunar. Surface dr.. David Cresswell has proposed, using, the lunar surface itself, as the collection medium, beaming, power to the ground via a series, of microwave, reflectors, in Earth orbit, the. Chief advantage of this approach would be the ability to manufacture the, solar collectors, in situ without the energy cost and complexity, of launch. Disadvantages. Include the much longer distance, requiring, larger, transmission, systems, the required overbilled to deal with the lunar night and the difficulty, of sufficient, manufacturing.
And Pointing, of reflector, satellites. Mayo. Mayo, systems, have been proposed, for in space utilities. And beam power propulsion. Infrastructures. For. Example, see Roy Jones paper, highly. Elliptical orbits. Molniya tundra, or quasi zenith orbits, have been proposed, as early locations, for niche markets, requiring, less energy, to access, and providing, good persistence. Sun. Sync leo in this near polar orbit, the satellites, process, at a rate that allows them to always face the Sun as they rotate around Earth this. Is an easy to access all but requiring, far, less energy and its proximity to earth requires, smaller, and therefore less massive transmitting. Apertures. However. Disadvantages. To this approach include having, to constantly shift, receiving, stations, or storing, energy for a burst transmission. This. Orbit is already crowded and has significant. Space debris. Equatorial. Leo Japan's, SPS, 2000. Proposed an early demonstrator, in equatorial, Leo in which multiple, equatorial. Participating. Nations could, receive some power Earth's. Surface, dr.. Narayan Komarov has proposed, a space power grid where excess, energy from an existing grid, or power plant on one side of the planet can be passed up to orbit across, to another satellite and down to receivers, energy, collection the most typical, designs for solar power satellites, include, photovoltaics. These. May be planar and usually, passively, called, concentrated. And perhaps actively. Cooled, however. There, are multiple interesting. Variants. Solar, thermal proponents. Of solar thermal have proposed using, concentrated, heating. To cause a state change in a fluid to extract, energy via rotating, machinery, followed, by cooling in radiators. Advantages. Of this method might include overall, system, mass disputed. Non degradation due, to solar wind damage and radiation, tolerance. One. Recent thermal, solar power satellite, design by keith henson and others has been visualized. Here, two. Solar. Pump laser japan, has pursued a solar pump laser where, sunlight directly excites. The lasting medium used to create the coherent, beam to earth. Fusion. Decay this version of a power satellite, is not solar. Rather. The, vacuum of space is, seen as a feature. Not a bug for. Traditional, fusion, / dr. paul huevos after, fusion even, neutral particles, decay two charged particles, which in a sufficiently, large volume, would allow direct, conversion to current. Solar. Wind loop also, called a dyson harab satellite, here. The satellite, makes use not of the photons, from the Sun but rather the charged particles, in the solar wind which, via electromagnetic. Coupling generator. Current, in a large loop. Direct. Mirrors early, concepts, for direct mirror redirection. Of light to planet Earth suffered, from the problem that rays coming from the Sun are not parallel but are expanding, from a disc and so the size of the spot on the earth is quite large. Dr.. Lewis frost has explored, an array of parabolic, mirrors to augment existing solar. Arrays alternate. Satellite, architecture. The typical, satellite is a monolithic, structure, composed of a structural, trust one or more collectors, one or more transmitters.
And Occasionally. Primary, and secondary reflectors. The. Entire, structure, may be gravity, gradient stabilized. Alternative. Designs, include. Swarms. Of smaller satellites, some designs propose, swarms, of free flying smaller, satellites. This. Is the case with several laser designs, and appears to be the case with CA LTE CA, is flying carpets, for RF designs and engineering, constraint, is the sparse array problem. Free-floating. Components. Solarian has proposed, an alternative to, the monolithic structure, where the primary reflector. And transmission, reflector, are free flying. Spin. Stabilization. NASA explored, a spin-stabilized, thin film concept. Photonic. Laser thruster, PLT, stabilized. Structure, dr., Jung Bay has proposed, that photon pressure may substitute, for compressive, members in large structures, transmission. The most typical design for energy transmission, is via an RF antenna at, below 10 gigahertz to, erect an ER on the ground. Controversy. Exists, between the benefits of klystrons, gyrotron. Magnetrons. And solid-state. Alternate. Transmission, approaches, include. Laser. Lasers. Offer the advantage, of much lower cost and mass to first power however, there is controversy regarding benefits, of efficiency. Lasers. Allow for much smaller transmitting. And receiving apertures. However. A highly, concentrated beam. Has eye safety, fire, safety and weaponization, concerns. Proponents. Believe they have answers, to all these concerns, a laser, based approach, must also find, alternate, ways of coping with precipitation. Atmospheric. Waveguide, some have proposed, it may be possible, to use a short pulse laser to create an atmospheric, waveguide, through which concentrated. Microwaves. Could flow. Nuclear. Synthesis, particle, accelerators. Based in the inner solar system weather, in orbit or on the planets such as mercury could use solar energy to synthesize, nuclear, fuel from naturally, occurring materials. While. This would be highly inefficient, using, current technology, in terms of the amount of energy needed to manufacture, the fuel compared, to the amount of energy contained, in the fuel and would raise obvious, nuclear, safety issues, the basic, technology upon, which such an approach would rely on has been in use for decades, making this possibly, the most reliable, means of sending energy especially, over very long distances in, particular from, the inner solar system to the outer solar system materials. And manufacturing typical. Design make use of the developed, industrial, manufacturing. System, extant, on earth and use earth-based materials. Both for the satellite and propellant. Variants. Include. Lunar. Materials, designs, exist, for solar power satellites, that source greater than 99%, of materials, from lunar regolith, with very small inputs, of vitamins. From. Other locations, using materials. From the moon is attractive, because launched from the moon is in theory far less complicated than from Earth there is no atmosphere and, so components. Do not need to be packed tightly in an era shell and survive vibration. Pressure and temperature, loads, launch. May be via a magnetic, mass driver and the requirement, to use propellant. For launch entirely. Launched. From the moon the Geo also, requires far less energy than from Earth's much deeper, gravity, well, building. All the solar power satellites, to fully supply, all the required energy for, the entire planet requires less than one millionth of the mass of the moon. Self-replication. On the moon NASA explored, a self-replicating. Factory, on the moon in 1980. More. Recently, Justin. Lewis Weber proposed, a method of speciated, manufacture. Of core elements, based upon John Mankins, SPS, alpha design. Asteroidal. Materials. Some, asteroids, are thought to have even lower delta v to recover materials than the moon and some particular materials. Of interest such, as metals may be more concentrated. Or easier to access, in. Space in situ, manufacturing. With the advent of in space additive, manufacturing, concepts. Such as spider valve might allow mass launch of raw materials, for local extrusion, method, of installation.
Transportation. Of material, to energy collection location. In the reference designs component. Material, is launched via a well understood chemical. Rockets, usually, fully reusable launch, systems, Tullio after, which either chemical, or electrical propulsion. Is, used to carry them to geo the. Desired, characteristics, for, this system, is very high mass flow at low total cost. Alternate. Concepts, include. Luna. Chemical launched Lula has recently showcased a concept, for a fully reusable chemical. Lander XE us to move materials, from the lunar surface to, llo or geo. Lunar. Mass driver launch, of materials, from the lunar surface using, a system similar to an aircraft carrier, electromagnetic. Catapult, an, unexplored. Compact, alternative. Would be the swinger Tron. Lunar. Space elevator, an equatorial, or near equatorial. Cable extends, to and through the Lagrange point, this. Is claimed by proponents, to be lower in mass than a traditional mass, driver. Space. Elevator, a ribbon of pure carbon nanotubes. Extends, from its center of gravity in geostationary. Orbit, allowing, climbers, to climb up to geo problems, with this include, the material, challenge of creating a ribbon of such length with adequate, strength management. Of collisions, with satellites, and space debris and lightning. Mayo. Skyhook. As part, of an AFRL, study roger leonard proposed a meio skyhook. It. Appears, that a gravity, gradient stabilized. Tether with its center of mass in Mayo can be constructed, of available, materials, the. Bottom of the skyhook, is close to the atmosphere, in a non Keplerian, orbit, a, reusable. Rocket can, launch to match altitude, and speed with, the bottom of the tether which is in a non Keplerian, orbit, traveling, much slower than typical, orbital, speed the. Payload, is transferred, and it climbs the cable the, cable itself, is kept from de orbiting, via electric, propulsion and/or, electromagnetic. Effects. Maglev. Launched start room john powell has a concept, for a very high mass flow system, in, a first-gen, system, built into a mountain accelerates. A payload through an evacuated, maglev, track a small. Onboard rocket, circulars, is the payload. Beamed. Energy launch, Kevin, Parkin, and escape dynamics, both have concepts, for ground-based, irradiation, of a monopropellant launch, vehicle, using, RF energy, the. RF energy is absorbed and directly, heats the propellant, not unlike in any RV a.style nuclear, thermal laser, motive, has a concept. A laser-based approach. Topic. In fiction. Space.
Station's, Transmitting. Solar power have appeared in science fiction works like Isaac Asimov's, reason. 1941. That centers, around the troubles caused by the robots, operating, the station. Asimov's. Short story, the, last question. Also, features, the use of SPSP, to provide limitless energy for use on earth, in. Ben bova z' novel power Sat 2005. An entrepreneur, strives to prove that his company's nearly, completed power satellite, and space plane a means of getting maintenance. Crews to the satellite, efficiently, are both safe and economically, viable while, terrorists, with ties to oil-producing, nations. Attempt to derail these attempts, through subterfuge and, sabotage, various, aerospace, companies, have also showcased, imaginative. Future solar power satellites, in their corporate vision videos, including. Boeing Lockheed, Martin, and United, Launch Alliance the, solar satellite, is one of three means of producing energy in the browser-based, game, o game. Equals. Equals see also.
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