Having abundant, safe, non-polluting energy could represent a tipping point for human productivity and creativity—that one essential ingredient enabling the human race not just to survive but to live up to its potential. If indeed solar energy can make that difference, let us work toward the possibility, as there are no other sustainable solutions currently available to meet our seemingly unending demands for power. References Bienhoff, D. Space infrastructure options for space based solar power.
Cleveland, Ohio. Bullis, K. Startup to beam power from space. Technology Review, April Accessed 5 July Potter, S. Bayer, D. Davis, A. Born, D. McCormick, L. Space solar power satellite alternatives and architectures. Orlando, Florida, 5—8 January Preble, D.
How to build a space solar power system: The Sunsat Incorporation Act. Space Solar Power Workshop. Accessed 23 January Sato, S. Accessed 15 September Yomiuri Shimbun. Space-based solar power set for 1st test. Abstract This chapter describes some of the challenges facing the planet as a result of burning fossil fuels, and the opportunities presented to the satellite industry in response to world demand for cleaner and more abundant energy.
Among the Sunsat uses discussed are the production of baseload electrical power—not just an intermittent source of power—supporting agriculture, saltwater desalination, disaster relief, military operations and related applications. Either way, he says, the world economy collapses Woodcock Alternative terrestrial energy is not the complete answer, either.
Terrestrial solar power works when the Sun shines. Terrestrial wind power works when the wind blows. Terrestrial hydroelectric power is a way of storing water energy until users demand it. This process can include hydroelectric pumped storage, which is the lifting of water uphill where it is held until released to create electricity as it flows through turbines. But there is little capacity remaining on the planet for hydroelectric installations. Geothermal energy is also way to tap stored energy in the Earth itself. Batteries, water electrolysis and hydrogen storage in fuel cells are other ways to provide storage.
But to run a modern power grid exclusively or even largely on terrestrial renewable energy, he says, would require enormous amounts of storage, and storage is expensive. Woodcock concludes that solar power satellites are a potential solution because they can be positioned in space over a particular location to which they can stream continuous sunlight. Supplying power around the clock, such an energy system can serve as a demand source with very little storage required.
He also suggests, given constant solar pointing, the photovoltaic area could probably be reduced by a factor of 10— by using concentrators. Land designated for receiving sites might also serve dual or multiple purposes. It produces regardless of cloud cover, daylight, or wind speed. Hsu and his NASA colleagues were engaged in monitoring and analyzing climate changes on a global scale, through which they received first-hand scientific information and data relating to global warming issues, including the dynamics of polar ice cap melting.
After discussing this research with colleagues who were world experts on the subject, he wrote: I now have no doubt global temperatures are rising, and that global warming is a serious problem confronting all of humanity. No matter whether these trends are due to human Satellite Power Markets 11 Fig. As a technology risk assessment expert, Hsu says he can show with some confidence that the planet will face more risk doing nothing to curb its fossil-based energy addictions than it will in making a fundamental shift in its energy supply.
Satellite Power Markets This new energy market will have lots of stakeholders. Those who contribute to the energy supply and those who receive benefits from an on-demand power resource will represent all sectors in all nations, including business and commerce, government and military and the public at large. Were satellite services to extend their range of offerings to include energy production, baseload electrical power and other applications could conceivably become a major new product line. Here are some illustrative examples. Power-to-Power Utilities One of the obvious opportunities for solar power satellites is to become an on-demand source of electric power for terrestrial utilities.
Once Sunsat providers can demonstrate the capability to direct continuous radio or light frequency power beams to production sites, the owners of coal-fired generation stations will quickly discover the value of this service. The same will also be true of nuclear, gas-fired, biomass and other such plants. With electrical power production ratings of 1 gw or more, solar satellite systems can be designed to meet the short- and long-term needs of the terrestrial power plants at their existing locations, at first to complement but eventually to replace their current fuel feedstocks.
An attractive feature of this approach for space solar power investors is that the utilities have a predictable need for energy in great quantities. Whether producing power from coal, nuclear, gas, biomass or other sources, power utilities can be expected to step forward as early users of this new space asset to begin reducing their mining and transportation costs.
The use of scrubbers and filters will be greatly reduced, if needed at all. Problems related to spent fuel disposal and toxic waste management should be fewer. But mainly the utilities will become clients and possibly investors in the Sunsat business to guarantee a sustainable night-and-day fuel source. Power-to-Agriculture In many places on Earth, the climate, soil and terrain does not permit cultivation.
With innovative applications of space solar power, it may be possible to establish multipurpose greenhouses and other agricultural facilities above which space-pointing Earth antennas have been installed for the purposes of producing heat along with electricity. Satellite Power Markets 13 An example is reclaimed strip mine land brought back to productive use with the cultivation of local vegetables, flowers and other high-value crops underneath a several kilometer space solar power antenna.
In this scenario, the SPS rectenna is a wire mesh energy receiver positioned above the greenhouses. The constant temperatures and light created in the generation of energy make for a month growing season. The wire mesh energy receiver produces electricity that can be used to operate machinery and supply the local power grid. This approach creates a business circle: an environmentally friendly energy production operation that can take advantage of seemingly worthless land to produce cash crops and have access to readily usable energy to stimulate the creation of new businesses, thereby improving the rural economy.
Power-to-Terrestrial Solar A slight modification of the power-to-agriculture approach will be the design and installation of an SPS rectenna that covers a terrestrial solar generation site, as in the case of solar farms. Engineers have already figured out that photovoltaic arrays can be designed with an integral antenna built-in, thereby maximizing efficiency, or such systems can be constructed with the space solar collectors working overhead.
In such cases, the dual-use installation assures h power production Landis Such installations do not yet exist, but the technical design and business plan for one of these could easily be modeled upon a project in Appalachian Ohio, where some acres of reclaimed land, mined by the Central Ohio Coal Co.
Kent Tobiska, a space environment scientist, says that one effect of adverse climate change is flooding and fresh water contamination. Population growth has also reduced water supplies while increasing demand. Tobiska, in a paper written for the American Institute of Aeronautics and Astronautics AAIA , notes that continued population growth in coastal areas makes it economically feasible to begin considering seawater desalination as a larger source for metropolitan water supplies. He also notes that the process of desalination is, however, energy intensive, which has discouraged its widespread use.
Tobiska , p. He writes: California offshore oil and gas platforms already use seawater desalination to produce fresh water for platform personnel and equipment. It is proposed that as California coastal oil and gas platforms come to the end of their productive lives, they be re-commissioned for use as large-scale fresh water production facilities. Solar arrays, mounted on the platforms, are able to provide some of the power needed for seawater desalination during the daytime. However, for efficient fresh water production, a facility must be operated 24 h a day.
The use of solar power transmitted from orbiting satellites Solar Power Satellites—SPS to substantially augment the solar array power generated from natural sunlight is a feasible concept.
The architecture of using an SPS in geosynchronous orbit will enable 24 h a day operations for fresh water production through seawater desalination. Production of industrial quantities of fresh water on re-commissioned oil and gas platforms, using energy transmitted from solar power satellites, is a breakthrough concept for addressing the pressing climate, water, and economic issues of the twenty-first century using space assets Tobiska Fig. Power-to-Cities It is predicted that by there will be 26 mega-cities—defined as a population area of ten million or more—in the world, primarily in the newly industrialized third world Landis , p.
Almost all of these high population areas will be scrambling to find the energy resources to meet even basic needs, with the more prosperous cities already having teams of planners trying to find answers. Here again, California can be used as illustration. The year contract with Solaren Corp. Air Force and Hughes Aircraft Company, with decades of experience in the space industry. Air Force and director of advanced digital applications at Boeing Satellite Systems, among other positions Marshall Among the arguments given was that the energy available in space is eight to ten times greater than on Earth.
Even if hard to reach, real estate in space is still free. Solaren would need to acquire land only for the receiving station, which it can locate near existing transmission lines. Where the rectenna is located can make some difference in reducing delays. The concept for a future-oriented solar power satellite solution to disaster recovery came from the team mentor Dean E.
Davis, aerospace systems engineer, Lockheed Martin Corporation Davis But destruction to the local infrastructure greatly slows rescue efforts, wasting precious recovery time. Finding ways to quickly recover from power outages and to restore communications in large-scale disasters can help to ameliorate its devastating results. Illumination: In the context of natural or man-made disasters, rescue workers need to be able to work around the clock.
Due to the absence of lighting, they are often limited to working full force only during the day. The lack of illumination can be addressed, in part, by satellites orbiting Earth. Networked in constellations, specially designed satellites will act as mirrors to reflect sunlight upon the spot facing a disaster situation. Each of these satellites will host a m-thin film solar-reflecting mirror orbiting in a Sun-synchronous orbit. Potentially, these satellites could focus between 10, and 20, lumens of light, or about as much light as the Sun gives off in the daytime.
This space-based asset will enable rescue workers to continue working at nighttime, thus making it possible to save time and lives. Power: Light alone will not be sufficient, as areas struck by disaster will also likely need electrical power. Terrestrial power can be replaced by space solar power. Although the first constellation of Sun-synchronous SEO Earth-orbiting satellites provides light, imagine a second set of orbiting satellites. With giant solar collectors onboard, the satellites will collect energy via their solar cells and convert the energy into electrical power, to be wirelessly transmitted to the ground.
In largescale emergencies, it can be expected that terrestrial sources of electrical energy will also be damaged; thus an intermediate power source is needed, which can be supplied with the help of a high-flying airship. Navigable airship: In this design, power in the form of laser energy will be sent from SEO solar power satellites to an intermediate platform hovering high in the stratosphere. The 1 gw is sufficient to power a million homes during a crisis, matching the capacity of a coal or nuclear power plant. Portable, expanding receptor antennas can be erected on site to receive this energy with the purpose of running generators or beefing up the existing electrical grid.
Emergency communications: When a devastating hurricane hits, one of the greatest constraints in providing relief will be the lack of communications.
In this design, the same airship providing power will be equipped to serve as a tall multi-purpose telecommunications tower, filling in as a relay and hub for telecommunication services. Search and rescue sensors: Such airships can also be equipped with passive electrooptical EO and active radar sensors allowing rescue managers to quickly scan the debris and locate people trapped in the aftermath of the disaster.
This task can be accomplished in a fraction of the time it would take to find them in other ways. The brief concludes that, in the event of a disaster, solar power satellites have an important role to play in saving lives as well as restoring order. With access to space-based solar power produced by Sun-synchronous satellite networks, rescue agencies will be able to direct electrical power to any location on the planet.
Although still in the planning stages, this technology is paving the way for an alternative power grid that can be used to the benefit of all Power All of these are possibilities. References Athens Messenger. Region poised to reap employment from giant solar farm on stripmined land. Accessed 7 October Davis, D. Hsu, F. Online Journal of Space Communication. Accessed 20 May Landis, G. Reinventing the solar power satellite. National Aeronautics Administration. Accessed 26 May Mankins, J.
A fresh look at space solar power: New architectures, concepts and technologies. Marshall, J. Space solar power: The next frontier? Accessed 13 April National Space Society. Space solar power: An investment for today, an energy solution for tomorrow. Ad Astra, 20 4 , p. Accessed 25 May Potter, D. The basis for the Sunsat visualization and technical brief provided by Ohio University students in Issue No. Tobiska, K. Vision for producing fresh water using space power. American Institute of Aeronautics and Astronautics.
Accessed 25 March Wang, U. Solaren to close funding for space solar power. Green Tech Media. Accessed 1 December Woodcock, G. Solar power satellites: A brief review. Accessed 15 May Abstract This chapter suggests several strategic designs for future Sunsats, to include substantially larger photovoltaic arrays in space, solar concentrators, energy converters, wireless power transmitters and power beaming.
Technical feasibility and some key technology challenges are addressed, including suitable orbits for Sunsat placement and managing the space environment. Hsu worked at Brookhaven National Laboratory, where he was a research fellow in such areas as risk assessment, safety and reliability and mission assurances for nuclear power, space launch and energy infrastructure. He is now an even stronger advocate of space power in his role as senior vice president of systems engineering and risk management with the Space Energy Group, a commercial enterprise focusing on renewable energy.
Hsu, who gave permission for his written responses to the Journal to be quoted here, notes that roughly 7—20 times less energy can be harvested per square meter on Earth than in space, depending on location. Likely, this is a principal reason why space solar power has been under consideration for more than 40 years.
To be historically correct, as early as Nikola Tesla, inventor of wireless communication, was writing about and seeking to demonstrate the means for broadcasting electrical power without wires. Tesla later addressed the American Institute of Electrical Engineers regarding his attempts to demonstrate long-distance wireless power transmission over the surface of Earth. Hsu noted that Dr. Peter Glaser first developed the concept of continuous power generation from space in Glaser et al.
The solar energy would be converted to direct current by solar cells; the direct current would in turn be used to power microwave generators in the gigahertz frequency range. The generators would feed a highly directive satellite-borne antenna, which would beam the energy to Earth. On the ground, a rectifying antenna rectenna would convert the microwave energy to direct current, which, after suitable processing, would be fed into the terrestrial power grid.
Hsu said the satellite would host a solar panel area of about 10 km2 in size, and a spaceto-Earth transmitting antenna of about 2 km in diameter.see
Benefits of space exploration
On the ground, a rectenna would be constructed about 4 km in diameter corresponding to the expected size and density of the energy beam. Such an installation could yield more than 1 gw of electric power, roughly equivalent to the productive capability of a large-scale nuclear power station. Commercial Viability Among the key SPS technology techniques are microwave generation and transmission, wave propagation, antennas and measurement calibration and wave control.
Hsu, New Architectures 21 satisfied that SPS meets each of the key criteria except for cost, which is increased by current space launch and propulsion technology. He continues: We all know that the expense of lifting and maneuvering material into space orbit is a major issue for future energy production in space. The development of autonomous robotic technology for on-orbit assembly of large solar PV or solar thermal structures along with the needed system safety and reliability assurance for excessively large and complex orbital structures are also challenges.
Nevertheless, no breakthrough technologies or any theoretical obstacles need to be overcome for a solar power satellite demonstration project to be carried out. Our society has repeatedly overlooked or dismissed the potential of space-based solar power. The U. A government-funded SPS demonstration project is overdue. What I really want to point out here is that we can solve the cost issue and make solar power satellites a commercially viable energy option.
We can do this through human creativity and innovation on both technological and economic fronts. Yes, current launch costs are critical constraints. However, in addition to continuing our quest for low cost RLV reusable launch vehicle technologies, there are business models for overcoming these issues. The SE approach is based on systematic development of solar technologies for terrestrial and for space environment applications. The company expects to rely on extensive terrestrial solar technology development as the stepping stone, focusing on the space-grade thin film PV technology innovations for launch cost reductions.
Increased demand in space tourism will certainly bring about a greater number of launches, which should drive down space transportation costs.
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New Architectures From to , NASA conducted a re-examination of the technologies, systems concepts and terrestrial markets that might be involved in future space solar power systems. A summary of the study, its goals and findings, is instructive for our consideration of Sunsat feasibility. Approximately experts in a wide variety of disciplines participated in this 2-year study, which involved three major workshops.
Working within the global energy marketplace of the twenty-first century—including a major focus on emerging nations—the study examined five different markets and about 30 different SPS concepts, ranging from the SPS Reference Concept defined by the U. Department of Energy and NASA to very advanced concepts involving technologies that have not yet been validated in the laboratory Fig. Several innovative concepts were defined and a variety of new technology applications considered, including solid state microwave transmitters, extremely large tension-stabilized structures both tethers and inflatable structures , and autonomously self-assembling systems using advanced in-space computing systems.
The study gave attention to what had changed to make it possible in and thereafter to consider implementing space-based systems for energy production. Mankins wrote that the most important contextual change was the increasing demand for energy globally and the growing concern regarding carbon combustion, CO2 emissions and global climate change. As a result, a major priority was being placed on the development of renewable energy sources. He also noted a change in U. This is, of course, an absolute requirement of space solar power. As the perceived cost of space solutions was thought to be a barrier, their approach was to examine and create the conceptual designs for more practical approaches to space power production and delivery Landis , p.
Three new concepts for solar power satellites were invented and analyzed. The concepts included 1 a solar power satellite positioned in a higher orbit e. The integral-array satellite had several advantages, including an initial investment cost approximately eight times lower than the conventional design. The related details of these approaches, including their disadvantages, can be found in the paper.
Previous space solar power architectures were designed to deliver h power; this design constraint was relaxed. Several findings of this study were thought to be helpful in accelerating Sunsat implementation. In the s, this team worked to address some of the problems of introducing and managing mechanical systems in space.
Seeking innovative solutions that might lead to more economically and technically feasible designs for solar power satellites, the researchers tackled four big issues: modularity, material systems, structural concepts and in-space operations. An example of this would be military bases in remote and hostile regions, where the logistics train for fuel to run generators is very expensive, dangerous and subject to constant disruption. Low power SSP systems may also be used in orbit around the Moon, Mars and other Solar System planets and moons to provide power to surface rovers and outposts.
The power generation level at the source for this first-phase application might be from to 5, kw. Such large satellites would be developed only when appropriate systems and technologies were sufficiently advanced to make them commercially viable. Using block upgrades on first-phase systems to develop and demonstrate the advanced technologies as they become available would reduce the cost, schedule and performance risks of very large system implementation. In addition, the probability of commercial system development success would be maximized because development would not begin prematurely Belvin et al.
The choice of wireless power transfer technology, specifically the wavelength RF or laser , would influence the SPS antenna size and thermal requirements. Large inflatable concentrators have been proposed as a way to reduce the Corporate Research 25 photovoltaic area and its cost , they said, but little attention has been paid to long-term space durability.
They concluded that technology advances in all four areas over the last 15 years make the technical feasibility of an operational SPS system much greater than it was just two decades ago. Several space scientists and engineers who were or are still employees of Boeing have spent almost their entire careers working on solar power satellite concepts, technologies and applications.
In , the Boeing team working in El Segundo and Huntington Beach, California, published an overview of space solar power satellite alternatives and architectures. System sizes are huge solar arrays several thousand meters across; power levels of thousands of megawatts. Due to the divergence of the microwave beam, a large amount of power must be collected to achieve an economically recoverable power density at the receiver array. Concluding Thoughts The new solar power satellite industry will position above Earth new types of energy infrastructure hosting many of the features of communications platforms, including a satellite bus physical structure , solar arrays, onboard processing, telemetry control and wireless transmission systems.
Whenever technological developments lead to thinner, lighter, cheaper photovoltaic PV cells that make terrestrial power production more efficient, those same benchmarks also benefit comsat systems in space. For solar power satellites, these same advancements will have a multiplying benefit many times greater.
This difference alone may make the launch of Sunsats possible sooner than later, since space producers of energy are looking to reduce the mass and increase the productivity of their antennas. Antenna size and weight are key to holding down costs of launching their considerably larger collector arrays into space. Also benefitting each of these space industries will be promising new developments in remote construction, assembly, repair and replacement.
Among the more innovative Sunsat-related designs are architectures that consist of more than one satellite, networking them together within a common space orbit, creating a larger photovoltaic mass. Such satellite systems may one day be interlinked for global service. References Belvin, W.
Solar power satellite development: Advances in modularity and mechanical systems. Accessed 1 May Glaser, P. Solar power satellites—The emerging energy option. New York: Ellis Horwood. Accessed 22 February Lecture given at the 38th International Astronautical Federation. Accessed September 12, References 27 Space Energy Group. Corporate Overview. Tesla, N. Experiments with alternate currents of high potential and high frequency. Accessed 16 May Abstract This chapter outlines several approaches to delivering powersats into low, medium, geosynchronous, Sun-synchronous and other space orbits.
A historical context is given and next-generation launch strategies are introduced. Increased spacecraft size, mass and deployment frequency of payloads and deployment are among the challenges discussed. Launching Sunsats As with communications satellites, solar power satellites must be lifted from Earth and delivered into designated orbits. Some will be positioned quite near Earth, while others will be farther away. To place any satellite in space for the purpose of relaying energy to the ground, providers of these services must go through a prior approval process with the International Telecommunications Union and other oversight authorities.
The more promising locations for directing power to Earth appear to be in LEO at roughly km, in the geosynchronous Earth orbit GEO at 36, km or in an elliptical orbit that will permit always-in-the-Sun reception. Others look to the Moon as a future base for collecting and beaming solar power to Earth. Such an energy source could be used as well for the electric propulsion of spacecraft into deeper space.
Among the more innovative Sunsat architectures are those that network multiple solar power satellites, treating them as a single photovoltaic mass serving one or more than one world region. An Historical Perspective Space engineer Ralph Nansen has spent much of his career designing, developing and advocating concepts that relate to space solar power. Starting as a designer on the Bomarc rocket-powered missile for the Boeing Company, Nansen was selected in to design the configuration used by Boeing in building the giant first stage of the Saturn V Moon rocket.
In , he became design manager of the Saturn S-1C fuel tanks, the first stage of the rocket that propelled the Apollo astronauts to the Moon. From to , Nansen served as Boeing solar power satellite program manager. He presented numerous papers and participated in international conferences on future space projects in Germany and Egypt.
Nansen was asked to testify before such Congressional committees as the Senate Space Subcommittee in and the House Subcommittee on Space and Aeronautics in and again in September Nansen retired from Boeing in and has since written two books on the world energy crisis and potential solutions from space. Nansen says the barrier to SPS development is the lack of a low-cost space transportation system for launching the satellite hardware. In his article for the Online Journal of Space Communication on the topic of low cost access to space, Nansen focuses on the specifics of developing a space transportation system based on reusable vehicles, an approach that he is confident will finally make solar power satellite deployment commercially viable.
To make the right choices for the future… we need to understand what is different now. To reach orbit, launch systems had to be made as light as possible to achieve orbital velocity. There was nothing left over for adding recovery systems that would allow reuse. As time went on, systems got more efficient, but overall program cost became a key decision maker.
To minimize cost, payload was reduced. The added cost of development for a reusable system was traded against the number of flights required. The other element was that many of the payloads needed to go to high orbits that made the recovery of the upper stages difficult and costly. As a result, the market was not large enough to justify the cost of a reusable system. The optimum manageable design was always to build a highly efficient expendable system.
Once the commercial satellite providers managed to become profitable using expendable rockets, the launch vehicle builders had no real incentive to develop reusable systems Nansen It was the plan for a space shuttle. The two biggest stumbling blocks were 1 the maximum gross liftoff weight and 2 the need to use hydrogen as the booster fuel. Hydrogen fuel use dictated a much larger vehicle than would be required with a hydrocarbon fuel booster.
The gross lift-off criterion was incompatible with hydrocarbon fuel and the size of a hydrogen fueled booster. None of the bidding contractors could meet the liftoff criteria. The question is: What can we do today to develop a reusable space transportation system with a minimum of developmental costs? Those principles are high usage, low maintenance, reasonably sized payloads, and ease of loading and unloading. When a transportation system reaches maturity with these characteristics, the cost of operating the system can be expected to be between three and five times the cost of fuel.
With the development of a fully reusable launch vehicle designed for commercial use by people who understand commercial operations, Nansen believes that solar power satellite hardware can be launched at a low enough cost that the satellites will provide competitively priced electricity to Earth. Launch Strategies It can be assumed that any solar power satellites built today will be launched on the same private, commercial and government rockets used by the comsat industry to lift their communications satellites.
It can also be assumed that, as cheaper and more suitable launch options appear, both Sunsat and comsat clients will benefit. The prospect of a new generation of satellites pursuing a new business category—that is, providing a continuous supply of clean and abundant energy to all countries—will give the launch industry the spurt of growth it has been hoping to see. The rocket will lift satellites and cargo weighing 53 t into low Earth orbit at km SpaceX opportunity to demonstrate that it can provide not only safe and reliable transport to space, but also can deliver it in sufficient volume and at sufficiently low cost to ensure the worldwide availability of competitively priced electricity Fig.
Bruce Elbert, in his widely used Introduction to Satellite Communication, points out that the three most common criteria in launch vehicle selection relate to launch mass capability, the reliability or success record of the system and the cost of use Elbert , p. Spacecraft are normally designed for compatibility with a particular launch vehicle to be placed into a specified orbit.
The place where a spacecraft is launched, whether on land, sea or in the air, will very much depend on its ultimate destination. For a spacecraft with a non-GEO destination, launch will likely occur from a site located at some higher latitude. In some cases the launch mission is completed short of the actual orbital destination when, for reasons of cost or complexity, the spacecraft is unloaded and caused to continue to the designated altitude and position using its own power.
This is most often the case with GEO satellites, when the launch vehicle places its payload into a geo-transfer orbit GTO. Reducing Costs 33 Fig. Other plans include inserting the solar spacecraft and its large arrays directly into orbit using more powerful and agile thrusters Fig. Reducing Costs Phillip Chapman, an Australian-born geophysicist and astronautical engineer who served as a scientist-astronaut for NASA during the Apollo era, wrote about economical launch vehicles, energy and environmental policy and space solar power in Issue No.
Giving thought to the cost of launching solar power satellites and incorporating launch technologies available today, he concluded that the cost of spaceflight is not a serious impediment to realizing the advantages of power from space. If it were possible to buy this energy in the form of electricity at U. Launch vehicles LVs are costly to build because the production volume is low; each LV is thrown away after one use. Annualized range costs are shared among just a few launches, and the staff members needed for LV construction and launch operations are grossly underemployed.
He calculates that economies of scale in any significant space-based solar power SBSP program will permit launch at acceptable cost, even without major advances in launch technology. The principal problems in closing the business case for a launch services provider that supports space-based solar power, he says, are related to financing the venture rather than the cost of operations or the eventual profitability.
Gordon Woodcock, honored in by the National Space Society for distinguished service in advancing the case for space-based solar power, has addressed the topic of launch costs on multiple occasions. Reusable Rockets 35 In a presentation at the International Space Development Conference in Chicago, Woodcock concluded that re-usable systems can deliver acceptable costs if 1 there is high demand; 2 these systems have long life; 3 there is a short turnaround time; and 4 they have modest turnaround cost.
His analysis shows fully reusable vehicles are not worth the investment unless demand is at least 50— launches per year, and that the turnaround is less than a week on the ground between flights. For getting started, he said, investment analysis shows a partially reusable heavy lift vehicle with flyback booster can be justified at 3—5 launches per year or more when there are additional purposes for such missions as human space exploration.
He assumes that the smaller, fully reusable passenger vehicles for space tourism to orbit are helpful steps along the way Woodcock , p. With its Falcon Heavy vehicle, SpaceX seeks to achieve a major reduction in launch costs. SpaceX CEO Elon Musk announced in April that the company had scheduled two or three Falcon 9 launches for , with launch rates ramping up to five or six in , growing to 12 per year by Air Force contracts, but would also compete with the Russian Proton and the European Arianes in the commercial marketplace. When measured in terms of the cost of placing a given satellite into orbit, he said, the Falcon 9 Heavy would be only half as expensive as the Russian Proton de Selding Space Exploration Technologies, Inc.
SpaceX is offering lower launch prices than they can. Alternative Approaches Multiple strategies abound for lifting people and material into space more efficiently, more often and less expensively. One of the less talked about strategies is to use highly focused laser or microwave power to lift satellite vehicles, their parts or payloads into LEO; another is the related space elevator.
A common version of the space elevator involves connecting a high strength ribbon a carbon nanotube tether from a space satellite to an offshore sea platform. Mechanical lifters attached to the ribbon would be propelled up the ribbon, pushing cargo into space. Dallas Bienhoff, in a paper presented to the AIAA, touched on some of these alternative approaches. Development costs for the suborbital RLV are reduced relative to typical RLVs due to the lower delta v requirements for launch and the need for smaller upper stages that perform orbit circularization only.
Upper stage capability requirement is reduced as the perigee burn function is provided by the tether. Operationally, the launch vehicle carries the payload to altitude and releases it in time to meet the passing tether payload hook. The tether rotates so the capture hook is traveling in the opposite direction as its center of mass when the payload is snatched to minimize the relative velocity between the RLV and capture hook. Tether design is such that the release velocity equals the perigee velocity required for the payload to reach its desired apogee.
An apogee burn is necessary for final orbit circularization. Space elevators…may offer the ultimate low-cost access to space. The climber has wheels, or grippers, that squeeze the ribbon and drive the carrier up to GEO. Lasers beam energy to photovoltaic cells on the climber, which provides the electricity to power the grippers. Depending on climber speeds, trip time to GEO may take anywhere from 1 to 10 days. Because space elevator Concluding Thoughts 37 ribbons are one-way paths, each elevator site will need two or more ribbons for efficient operations; one for Earth-bound climbers and one or more for space-bound climbers Bienhoff , p.
Instead of explosive chemical reactions onboard a rocket, beamed thermal propulsion would launch a rocket by shining laser light or microwaves at it from the ground Patel , p. Beamed thermal propulsion systems would involve focusing the beams on a heat exchanger aboard the rocket. Proponents suggest that this approach would make possible a reusable single-stage rocket that has 2—5 times more payload space than conventional rockets, dramatically slashing the cost of sending payloads into a low Earth orbit.
NASA is now conducting such a study to examine the possibility of using beamed energy propulsion for future space launches. Kare had calculated that it would take 8—10 min for a laser to put a craft into orbit, while microwaves would do the job in 3—4 min. Such launch systems would be built in high-altitude desert areas, so danger to wildlife would be minimized Patel , p. Concluding Thoughts Launching satellites safely and economically into space is one of many significant challenges facing the satellite industry.
The Twenty-First Century Commercial Space Imperative: Anthony Young: uwigeqapiruq.cf
Any positive momentum toward cheaper launches will be good news for space energy, space communications and related space businesses. To avoid the high costs of launching people and cargo into space, some visionaries see space-based infrastructures being built from materials found in space, with robotic manufacturing and assembly managed from Earth via virtual communications and control. Although this seems far off, solar power plants operating in near-Earth orbits can be expected to provide a near-term market large enough to stimulate a more diverse space transportation system.
These developments mesh well together. With lower cost space transportation, energy from space becomes the go-to source for supplemental and eventually replacement power, the volume of which will drive down overall costs. Chapman, P. Deploying SunSats. Accessed 2 May Space News. Accessed 28 May Elbert, B. Introduction to Satellite Communication.
USA: Artech House. Hopkins, M. International Space Development Conference. Huntsville, Alabama. May Morring, Jr. Cut rate. Accessed 24 May Nansen, R. Low cost access to space is key to solar power satellite deployment. Patel, P.
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- Works (239).
Beaming rockets into space. Development Conference-Chicago, May Zak, A. China considers big rocket power. BBC News, 26 July Abstract This chapter addresses both potential opportunities and expressed concerns relating to wireless transmission of space solar energy to Earth in baseload and related electrical power applications. Safety protections associated with the design, location and redistribution of energy on the ground are also discussed. Building on the revenue from this market, the intent is to then proceed in the construction of the large space power stations that can generate solar electric power for all nations.
Thus the first point to make is that competing with the efficient, reliable terrestrial utility and power grid is not the principal purpose of a space-based electric power resource. Narayanan Komerath, professor at the Daniel Guggenheim School of Aerospace Engineering at Georgia Tech, has been engaged with the idea of a global space power grid since The amount of electricity consumed on a hot summer evening can be 2—3 times greater than the amount consumed in the middle of the night during temperate weather. Because wind and terrestrial solar power sources are intermittent, auxiliary generators, which are expensive and fossil-burning, are needed at these plants to guarantee a steady baseload power flow.
One advantage of nuclear power plants is that they can reliably meet baseload demand. The Georgia Institute of Technology proposal takes a year perspective, foreseeing a constellation of power-generating satellites capable of converting sunlight into as much as 4 terawatts of usable energy.
This energy will be beamed to widely dispersed wholesale and retail markets on the ground. The first step toward this type of space power grid, according to the team, is a U. Two possible approaches to the first constellation achieving a nearh power exchange demo across countries are 1 four to six satellites at 5, km nearequatorial orbits, with ground stations in the United States, India, Australia and Egypt and 2 six satellites in 5, km orbits, with ground stations only in the United States and India.
This approach Historical Perspective 41 Fig. Historical Perspective The scale and the potential impact of solar power satellite designs are much greater in than they were when the U. House Committee on Science and Technology asked for a study of the concept in Glaser, the widely acknowledged author of the concept. However, the ultimate need for SPS and its rate of development will depend on the rate of increase in demand for electricity, and the ability of other energy supply options to meet ultimate demand more competitively.
Public Policy Concerns In the process of carrying out its research and deliberations, the OTA conducted an assessment of the potential environmental and human impacts of solar power satellites. This was perhaps the most thorough examination of such public policy issues as environment and health risks, land-use and receiver siting and military implications ever to have been done. A possible exception is coal, particularly if CO2 concerns are proven justified. The study identified several health and environmental effects thought to be unique to SPS but whose severity and likelihood were uncertain.
These included effects on the upper atmosphere from launch effluents and power transmission, human health hazards associated with non-ionizing radiation, radiation exposure for space workers and electromagnetic interference with other systems and with astronomy. Current day research and expert opinion on most of these topics are addressed in Chap.
Public Policy Concerns 43 The study team acknowledged that too little was known about the biological effects of long-term exposure to low-level microwave radiation to assess the health risks associated with SPS microwave systems. Further research is critically needed in order to set human-health exposure limits.
In light of the widespread proliferation of electromagnetic devices and the current controversy surrounding the use of microwave technologies, it is clear that increased understanding of the effects of microwaves on living things is vitally needed even if SPS is never deployed.
The power density of a focused laser system beam could be sufficiently great to incinerate some biological matter. Outside the beam, scattered laser light could constitute an ocular and skin hazard. The light delivered to Earth by the mirror system, even in combination with the ambient daylight, would never exceed that in the desert at high noon. The health impacts that might be adverse include psychological and physiological effects of h-per-day sunlight and possible ocular damage from viewing the mirrors, especially through binoculars Gibbons , pp.
While the most significant effect of the laser and mirror systems is probably weather modification due to tropospheric heating, ionospheric heating is most important for the microwave systems operating at 2. The report explains further: Experiments indicate that the effects on telecommunications of heating the lower ionosphere are negligible for the systems tested. The injection of rocket exhaust, particularly water vapor, into the ionosphere could lead to the depletion of large areas of the ionosphere.
While the uncertainties are greatest for the lower ionosphere, experiments are needed to test more adequately telecommunications impacts and to improve our theoretical understanding of chemical-electrical interactions throughout the ionosphere. In the troposphere, ground clouds generated during liftoff could modify local weather and air quality on a short-term basis. Additional experiments and improved atmospheric theory are needed to understand and quantify the above impacts under SPS conditions.
In addition, mitigating steps such as trajectory control, alternate space vehicle design, and the mining of lunar materials need to be assessed. Atmospheric studies would play a major role in the choice of frequency for power transmission Gibbons , p. Offshore siting and multiple use siting might each alleviate some of the difficulties associated with dedicated land-based receivers, but require further study.
There are two components to the siting issue: technical and political. It is clear that the choice of frequency, ionospheric heating limits, and radiation standards could have an impact on the land requirements. Further study is needed to understand fully the environmental and economic impacts of a receiver system on candidate sites and to determine if enough sites can be located to satisfy the technical requirements Gibbons , p. The earlier NASA technical reference designs had suggested the need for large contiguous plots of land dedicated to one use. The plausibility of multiple uses e.
The report concluded that the regional political problems may be more severe than the technical ones, especially in light of past controversies over the siting of power plants, power lines, and military radar and other facilities. Space Communications An assumption of the writers of the OTA report was that all artificial Earth satellites would be using some portion of the electromagnetic spectrum for communication.
Some would also use spectrum for remote sensing. All would be affected in one way or another by SPS Gibbons , p. Study members thought that geosynchronous satellites would be most strongly affected by the microwave systems, experiencing interference from noise at the 2. However, the magnitude of the power level at the central frequency and in harmonic frequencies for a microwave SPS is so great that the possibility of degrading the performance of satellite receivers and transmitters from these spurious effects is high.
In this effect, microwave signals traveling in a straight line between GEO communications satellites would experience interference from the same signal reflected from the surface of the power satellite. The sum of all these effects would result in a limit on the distance that a geosynchronous satellite must have from the SPS in order to operate effectively. The minimum necessary spacing would depend directly on the physical design of the satellite, the wavelength at which it operated and the type of transmission device used i.
The laser and mirror systems might also interfere with nongeosynchronous satellites by causing reflected sunlight to blind their optical sensors or by passing through communications beams. The footprints of early communications satellites—the spot on Earth illuminated by its power beams—were often as wide as one-third of Earth. Using spot beam technologies, such satellites can target areas of square miles or less. An estimated currently active comsats are positioned in geosynchronous orbit GEO. An even larger number of communications satellites are in MEO and LEO, including those collecting and using power for remote sensing, surveillance, weather, geo-positioning, satphone and military applications.
According to a NASA website, that number might be as high as 3, Although their power ratings may be somewhat less, the total energy gathered and transmitted to Earth as microwaves is likely to be 10 times greater than those in the higher fixed orbit. Orbiting comsats obviously collect and transmit less energy than is proposed for the new Sunsats. While the antennas of communications satellites are measured in meters and millimeters, those of solar power satellites will be measured in kilometers.
For siting and permitting, the U. Large-scale solar energy projects within these zones were to receive streamlined authorization and preferential treatment. The announcement followed a report by the Departments of Interior and Energy of a 2-year environmental analysis of millions of acres of public land assessing environmental and other impacts of solar energy development. Sunsat providers, in partnership with terrestrial solar businesses, may find future rectenna siting, and health, environmental and other public concerns easier to address as nations take steps to create more of their own energy.
References Dessanti, B. Environment News Service. Solar energy zones identified in six western states. Accessed 17 December Gibbons, J. Solar power satellites. Office of Technology assessment. Lore Lightborne Lore. Bookshelves Pocket Diary Bodleian Libraries This week-to-view pocket diary has a foil and embossed cover with magnetic closure. On Offer Wham! New Popular Science! Season 1 The Haunting of Hill House All ten episodes from the first season of the supernatural horror.
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