![Solar power satellite sandwich or abascus concept](https://upload.wikimedia.org/wikipedia/commons/1/1a/Solar_power_satellite_sandwich_or_abascus_concept.jpg)
Space-based solar power (SBSP, SSP) is the concept of collecting
solar power
Solar power is the conversion of energy from sunlight into electricity, either directly using photovoltaics (PV) or indirectly using concentrated solar power. Photovoltaic cells convert light into an electric current using the photovoltaic e ...
in
outer space
Outer space, commonly shortened to space, is the expanse that exists beyond Earth and its atmosphere and between celestial bodies. Outer space is not completely empty—it is a near-perfect vacuum containing a low density of particles, pred ...
by solar power satellites (SPS) and distributing it to
Earth
Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...
. Its advantages include a higher collection of energy due to the lack of
reflection Reflection or reflexion may refer to:
Science and technology
* Reflection (physics), a common wave phenomenon
** Specular reflection, reflection from a smooth surface
*** Mirror image, a reflection in a mirror or in water
** Signal reflection, in ...
and absorption by the
atmosphere
An atmosphere () is a layer of gas or layers of gases that envelop a planet, and is held in place by the gravity of the planetary body. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A s ...
, the possibility of no (or very little) night, and a better ability to orient to face the sun. Space-based solar power systems convert
sunlight
Sunlight is a portion of the electromagnetic radiation given off by the Sun, in particular infrared, visible, and ultraviolet light. On Earth, sunlight is scattered and filtered through Earth's atmosphere, and is obvious as daylight when t ...
to some other form of energy (such as
microwave
Microwave is a form of electromagnetic radiation with wavelengths ranging from about one meter to one millimeter corresponding to frequencies between 300 MHz and 300 GHz respectively. Different sources define different frequency ran ...
s) which can be transmitted through the atmosphere to receivers on the Earth's surface. It is attractive to those seeking large-scale solutions to
anthropogenic climate change
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...
or fossil fuel depletion (such as
peak oil
Peak oil is the hypothetical point in time when the maximum rate of global oil production is reached, after which it is argued that production will begin an irreversible decline. It is related to the distinct concept of oil depletion; while ...
).
Various SBSP proposals have been researched since the early 1970s,
but none is economically viable with present-day space launch costs. Some technologists speculate that this may change in the distant future with
space manufacturing
Space manufacturing is the production of tangible goods beyond Earth. Since most production capabilities are limited to low Earth orbit, the term in-orbit manufacturing is also frequently used.
There are several rationales supporting in-space ...
from asteroids or lunar material, or with
radical new space launch technologies other than rocketry.
Besides cost, SBSP also introduces several technological hurdles, including the problem of transmitting energy from orbit. Since wires extending from
Earth's surface
Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surface ...
to an orbiting satellite are not feasible with current technology, SBSP designs generally include the
wireless power transmission
Wireless power transfer (WPT), wireless power transmission, wireless energy transmission (WET), or electromagnetic power transfer is the transmission of electrical energy without wires as a physical link. In a wireless power transmission system ...
with its concomitant conversion inefficiencies, as well as land use concerns for antenna stations to receive the energy at Earth's surface. The collecting satellite would convert solar energy into electrical energy, powering a
microwave
Microwave is a form of electromagnetic radiation with wavelengths ranging from about one meter to one millimeter corresponding to frequencies between 300 MHz and 300 GHz respectively. Different sources define different frequency ran ...
transmitter or
laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The fir ...
emitter, and transmit this energy to a collector (or microwave
rectenna
A rectenna (''rec''tifying ant''enna'') is a special type of receiving antenna that is used for converting electromagnetic energy into direct current (DC) electricity. They are used in wireless power transmission systems that transmit power by r ...
) on Earth's surface. Contrary to appearances in fiction, most designs propose beam energy densities that are not harmful if human beings were to be inadvertently exposed, such as if a transmitting satellite's beam were to wander off-course. But the necessarily vast size of the receiving antennas would still require large blocks of land near the end users. The service life of space-based collectors in the face of long-term exposure to the space environment, including degradation from
radiation
In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium. This includes:
* ''electromagnetic radiation'', such as radio waves, microwaves, infrared, visi ...
and
micrometeoroid
A micrometeoroid is a tiny meteoroid: a small particle of rock in space, usually weighing less than a gram. A micrometeorite is such a particle that survives passage through Earth's atmosphere and reaches Earth's surface.
The term "micrometeoroid ...
damage, could also become a concern for SBSP.
As of 2020, SBSP is being actively pursued by Japan, China, Russia, India, the United Kingdom and the US.
In 2008, Japan passed its Basic Space Law which established space solar power as a national goal and
JAXA
The is the Japanese national air and space agency. Through the merger of three previously independent organizations, JAXA was formed on 1 October 2003. JAXA is responsible for research, technology development and launch of satellites into orb ...
has a roadmap to commercial SBSP.
In 2015, the
China Academy for Space Technology (CAST) showcased their roadmap at the International Space Development Conference. In February 2019, ''
Science and Technology Daily
''Science and Technology Daily'' (, Keji Ribao) is the official newspaper of the Ministry of Science and Technology of the People's Republic of China. It is published in Chinese and based in Beijing. Historically, it was one of the few Chinese ...
'' (科技日报, Keji Ribao), the official newspaper of the
, reported that construction of a testing base had started in Chongqing's Bishan District. CAST vice-president Li Ming was quoted as saying China expects to be the first nation to build a working space solar power station with practical value. Chinese scientists were reported as planning to launch several small- and medium-sized space power stations between 2021 and 2025. In December 2019,
Xinhua News Agency
Xinhua News Agency (English pronunciation: )J. C. Wells: Longman Pronunciation Dictionary, 3rd ed., for both British and American English, or New China News Agency, is the official state news agency of the People's Republic of China. Xinhua ...
reported that China plans to launch a 200-tonne SBSP station capable of generating megawatts (MW) of electricity to Earth by 2035.
In May 2020, the
US Naval Research Laboratory
The United States Naval Research Laboratory (NRL) is the corporate research laboratory for the United States Navy and the United States Marine Corps. It was founded in 1923 and conducts basic scientific research, applied research, technological ...
conducted its first test of solar power generation in a satellite. In August 2021, the
California Institute of Technology
The California Institute of Technology (branded as Caltech or CIT)The university itself only spells its short form as "Caltech"; the institution considers other spellings such a"Cal Tech" and "CalTech" incorrect. The institute is also occasional ...
(Caltech) announced that it planned to launch a SBSP test array by 2023, and at the same time revealed that
Donald Bren
Donald Leroy Bren (born May 11, 1932) is an American businessman. He is chairman and owner of the Irvine Company, a US real estate development corporation. With a net worth of $16.2 billion, he ranks number 112 on the 2022 Forbes Billionaires ...
and his wife Brigitte, both Caltech trustees, had been since 2013 funding the institute's Space-based Solar Power Project, donating over $100 million.
History
![Space to ground microwave, laser pilot beam](https://upload.wikimedia.org/wikipedia/commons/6/66/Space_to_ground_microwave%2C_laser_pilot_beam.png)
In 1941, science fiction writer
Isaac Asimov
yi, יצחק אזימאװ
, birth_date =
, birth_place = Petrovichi, Russian SFSR
, spouse =
, relatives =
, children = 2
, death_date =
, death_place = Manhattan, New York City, U.S.
, nationality = Russian (1920–1922)Soviet (192 ...
published the science fiction short story "
Reason
Reason is the capacity of consciously applying logic by drawing conclusions from new or existing information, with the aim of seeking the truth. It is closely associated with such characteristically human activities as philosophy, science, ...
", in which a space station transmits energy collected from the Sun to various planets using microwave beams. The SBSP concept, originally known as satellite solar-power system (SSPS), was first described in November 1968. In 1973
Peter Glaser
Peter Edward Glaser (September 5, 1923 – May 29, 2014) was a Czechoslovakian-born American scientist and aerospace engineer. He served as Vice President, Advanced Technology (1985–94), was employed at Arthur D. Little, Inc., Cambridge, MA (19 ...
was granted U.S. patent number 3,781,647 for his method of transmitting power over long distances (e.g. from an SPS to Earth's surface) using
microwave
Microwave is a form of electromagnetic radiation with wavelengths ranging from about one meter to one millimeter corresponding to frequencies between 300 MHz and 300 GHz respectively. Different sources define different frequency ran ...
s from a very large antenna (up to one square kilometer) on the satellite to a much larger one, now known as a
rectenna
A rectenna (''rec''tifying ant''enna'') is a special type of receiving antenna that is used for converting electromagnetic energy into direct current (DC) electricity. They are used in wireless power transmission systems that transmit power by r ...
, on the ground.
Glaser then was a vice president at
Arthur D. Little
Arthur D. Little is an international management consulting firm originally headquartered in Boston, Massachusetts, United States, founded in 1886 and formally incorporated in 1909 by Arthur Dehon Little, an MIT chemist who had discovered acetate. ...
, Inc. NASA signed a contract with ADL to lead four 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.
[ Glaser, P. E., Maynard, O. E., Mockovciak, J., and Ralph, E. L, Arthur D. Little, Inc., "Feasibility study of a satellite solar power station", NASA CR-2357, NTIS N74-17784, February 1974]
Concept Development and Evaluation Program
Between 1978 and 1986, the
Congress
A congress is a formal meeting of the representatives of different countries, constituent states, organizations, trade unions, political parties, or other groups. The term originated in Late Middle English to denote an encounter (meeting of a ...
authorized the
Department of Energy A Ministry of Energy or Department of Energy is a government department in some countries that typically oversees the production of fuel and electricity; in the United States, however, it manages nuclear weapons development and conducts energy-rel ...
(DoE) and
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research.
NASA was established in 1958, succeeding t ...
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 $50 million).
[Statement of John C. Mankins](_blank)
U.S. House Subcommittee on Space and Aeronautics Committee on Science, Sep 7, 2000 Several reports were published investigating the engineering feasibility of such a project. They include:
![NASA solar power satellite concept 1976](https://upload.wikimedia.org/wikipedia/commons/8/86/NASA_solar_power_satellite_concept_1976.jpg)
* Resource Requirements (Critical Materials, Energy, and Land)
* Financial/Management Scenarios
* Public Acceptance
* State and Local Regulations as Applied to Satellite Power System Microwave Receiving Antenna Facilities
* Student Participation
* Potential of Laser for SBSP Power Transmission
* International Agreements
* Centralization/Decentralization
* Mapping of Exclusion Areas For Rectenna Sites
* Economic and Demographic Issues Related to Deployment
* Some Questions and Answers
* Meteorological Effects on Laser Beam Propagation and Direct Solar Pumped Lasers
* Public Outreach Experiment
* Power Transmission and Reception Technical Summary and Assessment
* Space Transportation
Discontinuation
The project was not continued with the change in administrations after the
1980 United States elections
The 1980 United States elections were held on Tuesday, November 4. Republican presidential nominee Ronald Reagan defeated incumbent Democratic President Jimmy Carter. Republicans also won control of the Senate, though Democrats retained a major ...
. The
Office of Technology Assessment
The Office of Technology Assessment (OTA) was an office of the United States Congress that operated from 1974 to 1995. OTA's purpose was to provide congressional members and committees with objective and authoritative analysis of the complex scien ...
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 an SPS demonstration or systems-engineering verification program would be a high-risk venture."
In 1997, NASA conducted its "Fresh Look" study to examine the modern state of SBSP 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 ETO ''
arth to Orbit' transportation down dramatically. This is, of course, an absolute requirement of space solar power."
Conversely,
Pete Worden
Pete or Petes or ''variation'', may refer to:
People
* Pete (given name)
* Pete (nickname)
* Pete (surname)
Fictional characters
* Pete (Disney), a cartoon character in the ''Mickey Mouse'' universe
* Pete the Pup (a.k.a. 'Petey'), a character ...
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. Worden referred to possible solutions as speculative, and which would not be available for decades at the earliest.
On November 2, 2012, China proposed space collaboration with India that mentioned SBSP, "may be Space-based Solar Power initiative so that both India and China can work for long term association with proper funding along with other willing space faring nations to bring space solar power to earth."
Exploratory Research and Technology program
![Solar power satellite sandwich or abascus concept](https://upload.wikimedia.org/wikipedia/commons/1/1a/Solar_power_satellite_sandwich_or_abascus_concept.jpg)
In 1999, NASA's Space Solar Power Exploratory Research and Technology program (SERT) 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.
SERT went about developing a solar power satellite (SPS) concept for a future
gigawatt
The watt (symbol: W) is the unit of power or radiant flux in the International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3. It is used to quantify the rate of energy transfer. The watt is named after James Wat ...
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. SERT proposed an
inflatable
An inflatable is an object that can be inflated with a gas, usually with air, but hydrogen, helium and nitrogen are also used. One of several advantages of an inflatable is that it can be stored in a small space when not inflated, since inflata ...
photovoltaic
Photovoltaics (PV) is the conversion of light into electricity using semiconducting materials that exhibit the photovoltaic effect, a phenomenon studied in physics, photochemistry, and electrochemistry. The photovoltaic effect is commercially us ...
gossamer structure with concentrator lenses or
solar heat engine
In thermodynamics and engineering, a heat engine is a system that converts heat to mechanical energy, which can then be used to do mechanical work. It does this by bringing a working substance from a higher state temperature to a lower state ...
s to convert
sunlight
Sunlight is a portion of the electromagnetic radiation given off by the Sun, in particular infrared, visible, and ultraviolet light. On Earth, sunlight is scattered and filtered through Earth's atmosphere, and is obvious as daylight when t ...
into electricity. The program looked both at systems in
sun-synchronous orbit
A Sun-synchronous orbit (SSO), also called a heliosynchronous orbit, is a nearly polar orbit around a planet, in which the satellite passes over any given point of the planet's surface at the same local mean solar time. More technically, it is ...
and
geosynchronous orbit
A geosynchronous orbit (sometimes abbreviated GSO) is an Earth-centered orbit with an orbital period that matches Earth's rotation on its axis, 23 hours, 56 minutes, and 4 seconds (one sidereal day). The synchronization of rotation and orbital ...
. Some of SERT's 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 reenter the discussion.
* Solar power satellites should no longer be envisioned as requiring unimaginably large initial investments in fixed infrastructure before the emplacement of productive 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 and 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.
*
Launch costs in the range of $100–$200 per kilogram of payload from
low Earth orbit
A low Earth orbit (LEO) is an orbit around Earth with a period of 128 minutes or less (making at least 11.25 orbits per day) and an eccentricity less than 0.25. Most of the artificial objects in outer space are in LEO, with an altitude never mor ...
to
Geosynchronous orbit
A geosynchronous orbit (sometimes abbreviated GSO) is an Earth-centered orbit with an orbital period that matches Earth's rotation on its axis, 23 hours, 56 minutes, and 4 seconds (one sidereal day). The synchronization of rotation and orbital ...
are needed if SPS is to be economically viable.
Japan Aerospace Exploration Agency
The May 2014
IEEE
The Institute of Electrical and Electronics Engineers (IEEE) is a 501(c)(3) professional association for electronic engineering and electrical engineering (and associated disciplines) with its corporate office in New York City and its operation ...
Spectrum magazine carried a lengthy article "It's Always Sunny in Space" by Susumu 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
Tokyo (; ja, 東京, , ), officially the Tokyo Metropolis ( ja, 東京都, label=none, ), is the capital and largest city of Japan. Formerly known as Edo, its metropolitan area () is the most populous in the world, with an estimated 37.468 ...
-based
Japan Aerospace Exploration Agency
The is the Japanese national air and space agency. Through the merger of three previously independent organizations, JAXA was formed on 1 October 2003. JAXA is responsible for research, technology development and launch of satellites into orb ...
(JAXA)."
JAXA announced on 12 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 12 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.
Advantages and disadvantages
Advantages
The SBSP 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
Noon (or midday) is 12 o'clock in the daytime. It is written as 12 noon, 12:00 m. (for meridiem, literally 12:00 noon), 12 p.m. (for post meridiem, literally "after noon"), 12 pm, or 12:00 (using a 24-hour clock) or 1200 (military time).
Solar ...
in space and full sun.
* Collecting surfaces could receive much more intense sunlight, owing to the lack of obstructions such as
atmospheric gasses,
cloud
In meteorology, a cloud is an aerosol consisting of a visible mass of miniature liquid droplets, frozen crystals, or other particles suspended in the atmosphere of a planetary body or similar space. Water or various other chemicals may co ...
s, dust and other weather events. Consequently, the intensity in orbit is approximately 144% 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 shadow is a dark area where light from a light source is blocked by an opaque object. It occupies all of the three-dimensional volume behind an object with light in front of it. The cross section of a shadow is a two-dimensional silhouette, o ...
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
In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium. This includes:
* ''electromagnetic radiation'', such as radio waves, microwaves, infrared, visi ...
, generally for 24 hours per day, whereas earth surface solar panels currently collect power for an average of 29% of the day.
[Collection at Earth's ]poles
Poles,, ; singular masculine: ''Polak'', singular feminine: ''Polka'' or Polish people, are a West Slavic nation and ethnic group, who share a common history, culture, the Polish language and are identified with the country of Poland in Ce ...
can take place for 24 hours per day, but there are very small loads demanded at the poles.
* 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
baseload
The base load (also baseload) is the minimum level of demand on an electrical grid over a span of time, for example, one week. This demand can be met by unvarying power plants, dispatchable generation, or by a collection of smaller intermittent e ...
or
peak load
In electrical engineering, a load profile is a graph of the variation in the electrical load versus time. A load profile will vary according to customer type (typical examples include residential, commercial and industrial), temperature and hol ...
power needs.
* Reduced
plant
Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclud ...
and
wildlife
Wildlife refers to domestication, undomesticated animal species (biology), species, but has come to include all organisms that grow or live wilderness, wild in an area without being species, introduced by humans. Wildlife was also synonymous ...
interference.
Disadvantages
The SBSP concept also has a number of problems:
* The large cost of launching a satellite into space. For 6.5 kg/kW, the cost to place a power satellite in GEO cannot exceed $200/kg if the power cost is to be competitive.
* Microwave optic requires GW scale due to
Airy disk
In optics, the Airy disk (or Airy disc) and Airy pattern are descriptions of the best- focused spot of light that a perfect lens with a circular aperture can make, limited by the diffraction of light. The Airy disk is of importance in physics, ...
beam spreading. Typically a 1 km transmitting disk at 2.45 GHz spreads out to 10 km at Earth distance.
* Inability to constrain power transmission inside tiny beam angles. For example, a beam of 0.002 degrees (7.2 arc seconds) is required to stay within a one kilometer receiving antenna target from geostationary altitude. The most advanced directional
wireless power transfer
Wireless power transfer (WPT), wireless power transmission, wireless energy transmission (WET), or electromagnetic power transfer is the transmission of electrical energy without wires as a physical link. In a wireless power transmission system ...
systems as of 2019 spread their
half power beam width
The beam diameter or beam width of an electromagnetic beam is the diameter along any specified line that is perpendicular to the beam axis and intersects it. Since beams typically do not have sharp edges, the diameter can be defined in many differ ...
across at least 0.9 arc degrees.
* 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 telerobotically. In addition to cost, astronauts working in GEO (geosynchronous Earth orbit) are exposed to unacceptably high radiation dangers and risk and cost about one thousand times more than the same task done telerobotically.
* The space environment is hostile; PV panels (if used) suffer about eight times the degradation they would on Earth (except at orbits that are protected by the magnetosphere).
*
Space debris
Space debris (also known as space junk, space pollution, space waste, space trash, or space garbage) are defunct human-made objects in space—principally in Earth orbit—which no longer serve a useful function. These include derelict spacecr ...
is a major hazard to large objects in space, particularly for large structures such as SBSP systems in transit through the debris below 2000 km. Collision risk is much reduced in GEO since all the satellites are moving in the same direction at very close to the same speed.
* The broadcast frequency of the microwave downlink (if used) would require isolating the SBSP systems away from other satellites. GEO space is already well used and would require coordinating with the
ITU-R
The ITU Radiocommunication Sector (ITU-R) is one of the three sectors (divisions or units) of the International Telecommunication Union (ITU) and is responsible for radio communications.
Its role is to manage the international radio-frequency sp ...
.
* The large size and corresponding cost of the receiving station on the ground. The cost has been estimated at a billion dollars for 5 GW by SBSP researcher
Keith Henson
Howard Keith Henson (born 1942) is an American electrical engineer and writer. Henson writes on subjects including space engineering, space law ( Moon treaty), memetics, cryonics, evolutionary psychology, and the physical limitations of Transh ...
.
* Energy losses during several phases of conversion from photons to electrons to photons back to electrons.
*
Waste heat
Waste heat is heat that is produced by a machine, or other process that uses energy, as a byproduct of doing work. All such processes give off some waste heat as a fundamental result of the laws of thermodynamics. Waste heat has lower utility ...
disposal in space power systems is difficult to begin with, but becomes intractable when the entire spacecraft is designed to absorb as much solar radiation as possible. Traditional
spacecraft thermal control
In spacecraft design, the function of the thermal control system (TCS) is to keep all the spacecraft's component systems within acceptable temperature ranges during all mission phases. It must cope with the external environment, which can vary in ...
systems such as radiative vanes may interfere with solar panel occlusion or power transmitters.
Design
Space-based solar power essentially consists of three elements:
# collecting solar energy in space with reflectors or inflatable mirrors onto
solar cell
A solar cell, or photovoltaic cell, is an electronic device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical and chemical phenomenon. s or heaters for thermal systems
#
wireless power transmission
Wireless power transfer (WPT), wireless power transmission, wireless energy transmission (WET), or electromagnetic power transfer is the transmission of electrical energy without wires as a physical link. In a wireless power transmission system ...
to Earth via
microwave
Microwave is a form of electromagnetic radiation with wavelengths ranging from about one meter to one millimeter corresponding to frequencies between 300 MHz and 300 GHz respectively. Different sources define different frequency ran ...
or
laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The fir ...
# receiving power on Earth via a
rectenna
A rectenna (''rec''tifying ant''enna'') is a special type of receiving antenna that is used for converting electromagnetic energy into direct current (DC) electricity. They are used in wireless power transmission systems that transmit power by r ...
, a microwave antenna
The 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
micrometeors and
solar flares
A solar flare is an intense localized eruption of electromagnetic radiation in the Sun's atmosphere. Flares occur in active regions and are often, but not always, accompanied by coronal mass ejections, solar particle events, and other solar phe ...
. Two basic methods of conversion have been studied:
photovoltaic
Photovoltaics (PV) is the conversion of light into electricity using semiconducting materials that exhibit the photovoltaic effect, a phenomenon studied in physics, photochemistry, and electrochemistry. The photovoltaic effect is commercially us ...
(PV) and
solar dynamic (SD). Most analyses of SBSP 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
Wireless power transfer (WPT), wireless power transmission, wireless energy transmission (WET), or electromagnetic power transfer is the transmission of electrical energy without wires as a physical link. In a wireless power transmission system ...
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.
Microwave power transmission
William C. Brown
William C. Brown (May 22, 1916 – February 3, 1999) was an American electrical engineer who helped to invent the crossed-field amplifier in the 1950s and also pioneered microwave power transmission in the 1960s.
Brown received his BSEE fro ...
demonstrated in 1964, during
Walter Cronkite
Walter Leland Cronkite Jr. (November 4, 1916 – July 17, 2009) was an American broadcast journalist who served as anchorman for the ''CBS Evening News'' for 19 years (1962–1981). During the 1960s and 1970s, he was often cited as "the mo ...
's
CBS
CBS Broadcasting Inc., commonly shortened to CBS, the abbreviation of its former legal name Columbia Broadcasting System, is an American commercial broadcast television and radio network serving as the flagship property of the CBS Entertainm ...
News program, a microwave-powered model
helicopter
A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attributes ...
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
Raytheon Technologies Corporation is an American multinational aerospace and defense conglomerate headquartered in Arlington, Virginia. It is one of the largest aerospace and defense manufacturers in the world by revenue and market capitaliza ...
program that beamed 30
kW of power over a distance of at 9.6% 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
Reunion may refer to:
* Class reunion
* Family reunion
Reunion, Réunion, Re-union, Reunions or The Reunion may also refer to:
Places
* Réunion, a French overseas department and island in the Indian Ocean
* Reunion, Commerce City, Colorado, US ...
(1997).
![Comparison of Laser and Microwave Power Transmission for Space Station Power](https://upload.wikimedia.org/wikipedia/commons/a/a6/Comparison_of_Laser_and_Microwave_Power_Transmission_for_Space_Station_Power.gif)
More recently, microwave power transmission has been demonstrated, in conjunction with solar energy capture, between a mountain top in Maui and the island of Hawaii (92 miles away), by a team under
John C. Mankins John C. Mankins is a former NASA physicist known for his work on space-based solar power.
Mankins holds a Bachelor of Science from Harvey Mudd College, a Master of Science in physics from UCLA, and an MBA in Public Policy Analysis from The Drucker ...
.
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
IEEE
The Institute of Electrical and Electronics Engineers (IEEE) is a 501(c)(3) professional association for electronic engineering and electrical engineering (and associated disciplines) with its corporate office in New York City and its operation ...
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.
Laser power beaming
Laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The fir ...
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 SELENE 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.
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, LEO requires several satellites before they are producing nearly continuous power.
Power beaming from
geostationary orbit
A geostationary orbit, also referred to as a geosynchronous equatorial orbit''Geostationary orbit'' and ''Geosynchronous (equatorial) orbit'' are used somewhat interchangeably in sources. (GEO), is a circular geosynchronous orbit in altitud ...
by microwaves carries the difficulty that the required 'optical aperture' sizes are very large. For example, the 1978 NASA SPS study required a 1-km diameter transmitting antenna, and a 10 km diameter receiving rectenna, for a microwave beam at
2.45 GHz. These sizes can be somewhat decreased by using shorter wavelengths, although they have increased
atmospheric absorption
In astronomy, extinction is the absorption and scattering of electromagnetic radiation by dust and gas between an emitting astronomical object and the observer. Interstellar extinction was first documented as such in 1930 by Robert Julius Trum ...
and even potential beam blockage by rain or water droplets. Because of the
thinned array curse, it is not possible to make a narrower 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 uneconomic.
A collection of LEO (
Low Earth Orbit
A low Earth orbit (LEO) is an orbit around Earth with a period of 128 minutes or less (making at least 11.25 orbits per day) and an eccentricity less than 0.25. Most of the artificial objects in outer space are in LEO, with an altitude never mor ...
) space power stations has been proposed as a precursor to GEO (
Geostationary Orbit
A geostationary orbit, also referred to as a geosynchronous equatorial orbit''Geostationary orbit'' and ''Geosynchronous (equatorial) orbit'' are used somewhat interchangeably in sources. (GEO), is a circular geosynchronous orbit in altitud ...
) space-based solar power.
Earth-based receiver
The Earth-based
rectenna
A rectenna (''rec''tifying ant''enna'') is a special type of receiving antenna that is used for converting electromagnetic energy into direct current (DC) electricity. They are used in wireless power transmission systems that transmit power by r ...
would likely consist of many short
dipole antenna
In radio and telecommunications a dipole antenna or doublet is the simplest and most widely used class of antenna. The dipole is any one of a class of antennas producing a radiation pattern approximating that of an elementary electric dipole w ...
s connected via
diode
A diode is a two-terminal electronic component that conducts current primarily in one direction (asymmetric conductance); it has low (ideally zero) resistance in one direction, and high (ideally infinite) resistance in the other.
A diode ...
s. 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. Rectennas would likely be several kilometers across.
In space applications
A laser SBSP could also power a base 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.
Launch costs
One problem for the SBSP concept is the cost of space launches and the amount of material that would need to be launched.
Much of the material launched 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 thruster
An ion thruster, ion drive, or ion engine is a form of electric propulsion used for spacecraft propulsion. It creates thrust by accelerating ions using electricity.
An ion thruster ionizes a neutral gas by extracting some electrons out of a ...
s or
nuclear propulsion
Nuclear propulsion includes a wide variety of propulsion methods that use some form of nuclear reaction as their primary power source. The idea of using nuclear material for propulsion dates back to the beginning of the 20th century. In 1903 it was ...
.
To give an idea of the scale of the problem, assuming a solar panel mass of 20 kg per kilowatt (without considering the mass of the supporting structure, antenna, or any significant mass reduction of any focusing mirrors) a 4 GW power station would weigh about 80,000
metric tons
The tonne ( or ; symbol: t) is a unit of mass equal to 1000 kilograms. It is a non-SI unit accepted for use with SI. It is also referred to as a metric ton to distinguish it from the non-metric units of the short ton ( United States ...
, all of which would, in current circumstances, be launched from the Earth. This is, however, far from the state of the art for flown spacecraft, which as of 2015 was 150W/kg (6.7 kg/kW), and improving rapidly. Very lightweight designs could likely achieve 1 kg/kW, meaning 4,000 metric tons for the solar panels for the same 4 GW capacity station. Beyond the mass of the panels, overhead (including boosting to the desired orbit and stationkeeping) must be added.
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 $3 billion to $6 billion per GW (not including the
full cost to the environment from emissions or storage of spent nuclear fuel, respectively).
Building from space
From lunar materials launched in orbit
Gerard O'Neill
Gerard Michael O'Neill (September 1, 1942 – August 22, 2019) was an American journalist, newspaper editor, and writer. A long time investigative reporter for ''The Boston Globe'', he was awarded the
Pulitzer Prize for Investigative Reportin ...
, noting the problem of high launch costs in the early 1970s, proposed building the SPS's in orbit with materials from the
Moon
The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...
.
Launch costs from the Moon are potentially much lower than from Earth, due to the lower
gravity
In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the stro ...
and lack of
atmospheric drag
In fluid dynamics, drag (sometimes called air resistance, a type of friction, or fluid resistance, another type of friction or fluid friction) is a force acting opposite to the relative motion of any object moving with respect to a surrounding flu ...
. This 1970s proposal assumed the then-advertised future launch costing of NASA's space shuttle. This approach would require substantial up front capital investment to establish
mass driver
A mass driver or electromagnetic catapult is a proposed method of non-rocket spacelaunch which would use a linear motor to Acceleration, accelerate and catapult Payload (air and space craft), payloads up to high speeds. Existing and contemplated ...
s on the Moon. Nevertheless, on 30 April 1979, the Final Report ("Lunar Resources Utilization for Space Construction") by General Dynamics' Convair Division, under NASA contract NAS9-15560, concluded that use of lunar resources would be cheaper than Earth-based materials for a system of as few as thirty solar power satellites of 10 GW capacity each.
In 1980, when it became obvious NASA's launch cost estimates for the space shuttle were grossly optimistic, O'Neill et al. published another route to manufacturing using lunar materials with much lower startup costs. This 1980s SPS concept relied less on human presence in space and more on partially
self-replicating systems on the lunar surface under
remote control
In electronics, a remote control (also known as a remote or clicker) is an electronic device used to operate another device from a distance, usually wirelessly. In consumer electronics, a remote control can be used to operate devices such as ...
of workers stationed on Earth. The high
net energy gain
Net Energy Gain (NEG) is a concept used in energy economics that refers to the difference between the energy expended to harvest an energy source and the amount of energy gained from that harvest. The net energy gain, which can be expressed in jo ...
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 and the
lunar space elevator
A lunar space elevator or lunar spacelift is a proposed transportation system for moving a mechanical climbing vehicle up and down a ribbon-shaped tethered cable that is set between the surface of the Moon "at the bottom" and a docking port suspe ...
, first described by Jerome Pearson. It would require establishing
silicon
Silicon is a chemical element with the symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic luster, and is a tetravalent metalloid and semiconductor. It is a member of group 14 in the periodic tab ...
mining and solar cell manufacturing facilities on the
Moon
The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...
.
On the Moon
Physicist Dr
David Criswell
David R. Criswell (July 17, 1941 – September 10, 2019) was the Director of the Institute for Space Systems Operations at the University of Houston. ISSO is the operational agent for the Houston Partnership for Space Exploration.
Criswell receiv ...
suggests the Moon is the optimum location for solar power stations, and promotes lunar-based solar power. The main advantage he envisions is construction largely from locally available lunar materials, using
in-situ resource utilization
In space exploration, in situ resource utilization (ISRU) is the practice of collection, processing, storing and use of materials found or manufactured on other astronomical objects (the Moon, Mars, asteroids, etc.) that replace materials that ...
, with a
teleoperated
Teleoperation (or remote operation) indicates operation of a system or machine at a distance. It is similar in meaning to the phrase "remote control" but is usually encountered in research, academia and technology. It is most commonly associat ...
mobile factory and crane to assemble the microwave reflectors, and rovers to assemble and pave solar cells, which would significantly reduce launch costs compared to SBSP designs. Power relay satellites orbiting around earth and the Moon reflecting the microwave beam are also part of the project. A demo project of 1 GW starts at $50 billion. The
Shimizu Corporation
is an architectural, civil engineering and general contracting firm. It has annual sales of approximately US$15 billion and has been widely recognized as one of the top 5 contractors in Japan and among the top 20 in the world.
It is a family bu ...
use combination of lasers and microwave for the
Luna Ring concept, along with power relay satellites.
From an asteroid
Asteroid mining
Asteroid mining is the hypothetical exploitation of materials from asteroids and other minor planets, including near-Earth objects.
Notable asteroid mining challenges include the high cost of spaceflight, unreliable identification of asteroids ...
has also been seriously considered. A 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% of the returned asteroid was useful, and that the asteroid miner itself couldn't be reused, that represents nearly a 95% 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 their composition. One proposal is to capture the asteroid
Apophis into earth orbit and convert it into 150 solar power satellites of 5 GW each or the larger asteroid 1999 AN10 which is 50x the size of Apophis and large enough to build 7,500 5-gigawatt solar power satellites
Gallery
Image:Lunar base concept drawing s78 23252.jpg, A Lunar base with a mass driver (the long structure that goes toward the horizon). NASA conceptual illustration
Image:Advanced Automation for Space Missions figure 5-19.jpg, An artist's conception of a "self-growing" robotic lunar factory.
File:Lunar solar power.jpg, Microwave reflectors on the moon and teleoperated robotic paving rover and crane.
File:Lunar solar crawler 2.png, "Crawler" traverses Lunar surface, smoothing, melting a top layer of regolith, then depositing elements of silicon PV cells directly on surface
File:Lunar solar crowler.png, Sketch of the Lunar Crawler to be used for fabrication of lunar solar cells on the surface of the Moon.
File:Solar.GIF, Shown here is an array of solar collectors that convert power into microwave beams directed toward Earth.
File:Solar power satellite from an asteroid.jpg, A solar power satellite built from a mined asteroid.
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 suggested microwave beam would have a maximum intensity at its center, of 23 mW/cm
2 (less than 1/4 the
solar irradiation constant), and an intensity of less than 1 mW/cm
2 outside the rectenna fenceline (the receiver's perimeter).
[
] These compare with current United States
Occupational Safety and Health Act
The Occupational Safety and Health Act of 1970 is a US labor law governing the federal law of occupational health and safety in the private sector and federal government in the United States. It was enacted by Congress in 1970 and was signed by P ...
(OSHA) workplace exposure limits for microwaves, which are 10 mW/cm
2, - 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, of a 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 rectenna. 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 rectenna. Outside the rectenna, 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 (e.g., via fencing), and typical aircraft flying through the beam provide passengers with a protective metal shell (i.e., a
Faraday Cage
A Faraday cage or Faraday shield is an enclosure used to block electromagnetic fields. A Faraday shield may be formed by a continuous covering of conductive material, or in the case of a Faraday cage, by a mesh of such materials. Faraday cage ...
), which will intercept the microwaves. Other aircraft (
balloon
A balloon is a flexible bag that can be inflated with a gas, such as helium, hydrogen, nitrous oxide, oxygen, and air. For special tasks, balloons can be filled with smoke, liquid water, granular media (e.g. sand, flour or rice), or light so ...
s,
ultralight
Ultralight aviation (called microlight aviation in some countries) is the flying of lightweight, 1- or 2-seat fixed-wing aircraft. Some countries differentiate between weight-shift control and conventional three-axis control aircraft with ailer ...
, etc.) can avoid exposure by observing airflight 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 rectennas offshore, but this presents serious problems, including corrosion, mechanical stresses, and biological contamination.
A commonly proposed approach to ensuring fail-safe beam targeting is to use a retrodirective
phased array
In antenna theory, a phased array usually means an electronically scanned array, a computer-controlled array of antennas which creates a beam of radio waves that can be electronically steered to point in different directions without moving th ...
antenna/rectenna. A "pilot" microwave beam emitted from the center of the rectenna on the ground establishes a phase front at the transmitting antenna. There, circuits in each of the antenna's subarrays compare the pilot beam's 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 rectenna 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 rectenna, 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.
Timeline
In the 20th century
* 1941: 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:
Peter Glaser
Peter Edward Glaser (September 5, 1923 – May 29, 2014) was a Czechoslovakian-born American scientist and aerospace engineer. He served as Vice President, Advanced Technology (1985–94), was employed at Arthur D. Little, Inc., Cambridge, MA (19 ...
introduces the concept of a "solar power satellite" system with square miles of solar collectors in high
geosynchronous orbit
A geosynchronous orbit (sometimes abbreviated GSO) is an Earth-centered orbit with an orbital period that matches Earth's rotation on its axis, 23 hours, 56 minutes, and 4 seconds (one sidereal day). The synchronization of rotation and orbital ...
for collection and conversion of sun's energy into a
microwave
Microwave is a form of electromagnetic radiation with wavelengths ranging from about one meter to one millimeter corresponding to frequencies between 300 MHz and 300 GHz respectively. Different sources define different frequency ran ...
beam to transmit usable energy to large receiving antennas (
rectenna
A rectenna (''rec''tifying ant''enna'') is a special type of receiving antenna that is used for converting electromagnetic energy into direct current (DC) electricity. They are used in wireless power transmission systems that transmit power by r ...
s) on Earth for distribution.
* 1973: Peter Glaser is granted
United States patent
Under United States law, a patent is a right granted to the inventor of a (1) process, machine, article of manufacture, or composition of matter, (2) that is new, useful, and non-obvious. A patent is the right to exclude others, for a limited ...
number 3,781,647 for his method of transmitting power over long distances using microwaves from a large (one square kilometer) antenna on the satellite to a much larger one on the ground, now known as a rectenna.
* 1978–81: The
United States Department of Energy
The United States Department of Energy (DOE) is an executive department of the U.S. federal government that oversees U.S. national energy policy and manages the research and development of nuclear power and nuclear weapons in the United Stat ...
and
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research.
NASA was established in 1958, succeeding t ...
examine the solar power satellite (SPS) concept extensively, publishing design and feasibility studies.
* 1987:
Stationary High Altitude Relay Platform a Canadian experiment
* 1995–97: NASA conducts a "Fresh Look" 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's 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 (''
SERT, see below'') begins.
* 2000: John Mankins of NASA testifies in the
U.S. House of Representatives
The United States House of Representatives, often referred to as the House of Representatives, the U.S. House, or simply the House, is the lower chamber of the United States Congress, with the Senate being the upper chamber. Together they ...
, 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 — albeit over several decades.
In the 21st century
* 2001:
NASDA
The , or NASDA, was a Japanese national space agency established on October 1, 1969 under the National Space Development Agency Law only for peaceful purposes. Based on the Space Development Program enacted by the Minister of Education, Culture, ...
(One of Japan's national space agencies before it became part of
JAXA
The is the Japanese national air and space agency. Through the merger of three previously independent organizations, JAXA was formed on 1 October 2003. JAXA is responsible for research, technology development and launch of satellites into orb ...
) announces plans to perform additional research and prototyping by launching an experimental satellite with 10 kilowatts and 1 megawatt of power.
* 2003:
ESA
, owners =
, headquarters = Paris, Île-de-France, France
, coordinates =
, spaceport = Guiana Space Centre
, seal = File:ESA emblem seal.png
, seal_size = 130px
, image = Views in the Main Control Room (1205 ...
studies
* 2007: The
US Pentagon
The Pentagon is the Headquarters (military), headquarters building of the United States Department of Defense. It was constructed on an accelerated schedule during World War II. As a symbol of the United States Armed Forces, U.S. military, the ...
's
National Security Space Office (NSSO) issues a report on October 10, 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
The Middle East ( ar, الشرق الأوسط, ISO 233: ) is a geopolitical region commonly encompassing Arabian Peninsula, Arabia (including the Arabian Peninsula and Bahrain), Anatolia, Asia Minor (Asian part of Turkey except Hatay Pro ...
and the battle for oil. A demo plant could cost $10 billion, produce 10 megawatts, and become operational in 10 years.
* 2007: In May 2007, a workshop is held at the US
Massachusetts Institute of Technology (MIT) to review the current state of the SBSP market and technology.
* 2010: Professors Andrea Massa and Giorgio Franceschetti announce a special session on the "Analysis of Electromagnetic Wireless Systems for Solar Power Transmission" at the 2010
Institute of Electrical and Electronics Engineers
The Institute of Electrical and Electronics Engineers (IEEE) is a 501(c)(3) professional association for electronic engineering and electrical engineering (and associated disciplines) with its corporate office in New York City and its operation ...
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: ''Sky's No Limit: Space-Based solar power, the next major step in the Indo-US strategic partnership?'' written by USAF Lt Col Peter Garretson was published at the Institute for Defence 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: Th
Space Solar Power Initiative (SSPI)is established between Caltech and Northrop Grumman Corporation. An estimated $17.5 million is to be provided over a three-year project for development of a space-based solar power system.
*2015: JAXA announced on 12 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: Lt Gen. Zhang Yulin, deputy chief of the
LAarmament 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 beam energy back to Earth.
* 2016:
teamwith membership from the Naval Research Laboratory (NRL), Defense Advanced Projects Agency (DARPA), Air Force Air University, Joint Staff Logistics (J-4), Department of State, Makins Aerospace and Northrop Grumman won the Secretary of Defense (SECDEF) / Secretary of State (SECSTATE) / USAID Director's agency-wide D3 (Diplomacy, Development, Defense) Innovation Challenge with
proposalthat the US must lead in space solar power. The proposal was followed by
vision video
* 2016:''
Citizens for Space-Based Solar Powerhas 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 followin
video
* 2016: Erik Larson and others from NOAA produce a paper "Global atmospheric response to emissions from a proposed reusable space launch system" The paper makes a case that up to 2 TW/year of power satellites could be constructed without intolerable damage to the atmosphere. Before this paper, there was concern that the produced by reentry would destroy too much ozone.
* 2016:''
Ian Cash of SICA Designproposes CASSIOPeiA (Constant Aperture, Solid State, Integrated, Orbital Phased Array) a new concept SP
Faculty Listing , Electrical and Computer Engineering*2017: NASA select
five new research proposalsfocused on investments in space. The Colorado School of Mines focuses on "21st Century Trends in Space-Based Solar Power Generation and Storage."
*2019: Aditya Baraskar and Prof Toshiya Hanada fro
Space System Dynamic Laboratory, Kyushu Universityproposed Energy Orbit (E-Orbit),
a small Space Solar Power Satellite constellation for power beaming between satellites in low earth orbit. A total of 1600 satellite to transmit 10 kilowatts of electricity in a 500 km radius at an altitude of 900 km. "
*2019: China creates a test base for SBSP, and announces plan to launch a working megawatt-grade 200-tonne SBSP station by 2035.
*2020: US Naval Research Laboratory launches test satellite.
Also the USAF has its
Space Solar Power Incremental Demonstrations and Research Project (SSPIDR) planning to launch the ARACHNE test satellite. Arachne is due to launch in 2024.
*2021:
Caltech
The California Institute of Technology (branded as Caltech or CIT)The university itself only spells its short form as "Caltech"; the institution considers other spellings such a"Cal Tech" and "CalTech" incorrect. The institute is also occasional ...
announces that it planned to launch a SBSP test array by 2023.
*2022: The
Space Energy Initiative in the
UK announced to launch the first power station in space during the mid-2040s, to "provide 30 percent of the UK’s (greatly increased) electricity demand" and "to slash the UK’s dependence on fossil fuels" and foreign ties.
*2022: The
European Space Agency
, owners =
, headquarters = Paris, Île-de-France, France
, coordinates =
, spaceport = Guiana Space Centre
, seal = File:ESA emblem seal.png
, seal_size = 130px
, image = Views in the Main Control Room (1205 ...
announced its plans to launch several Solar Power Satellites under the name Solaris. It is stated that these installations would be about 10 times greater than the current ISS (International Space Station). The whole network of these Oribtal Powerplants would produce about 1.000 TWh, which comes down to a third of the whole energy consumption of the European Union.
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 1-10 GW range and usually involves planar or concentrated solar photovoltaics (PV) as the energy collector / conversion. The most typical transmission designs are in the 1–10 GHz (2.45 or 5.8 GHz) 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 re-usable rocket launch, and transported between LEO and GEO via chemical or electrical propulsion. In summary, the architecture choices are:
* Location = GEO
* Energy Collection = PV
* Satellite = Monolithic Structure
* Transmission = RF
* Materials & Manufacturing = Earth
* Installation = RLVs to LEO, Chemical to GEO
There are 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 demand several times over, other locations have been proposed:
* Sun Earth L1: Robert Kennedy III, Ken Roy & 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 sun-synchronous receiver satellites. The much farther distance to Earth requires a correspondingly larger transmission aperture.
* Lunar surface:
David Criswell
David R. Criswell (July 17, 1941 – September 10, 2019) was the Director of the Institute for Space Systems Operations at the University of Houston. ISSO is the operational agent for the Houston Partnership for Space Exploration.
Criswell receiv ...
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 "overbuild" to deal with the lunar night, and the difficulty of sufficient manufacturing and pointing of reflector satellites.
* MEO: MEO systems have been proposed for in-space utilities and beam-power propulsion infrastructures. For example, see Royce Jones' paper.
* Highly elliptical orbits: Molniya, Tundra, or Quazi 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 precess at a rate that allows them to always face the Sun as they rotate around Earth. This is an easy to access orbit 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: Narayan Komerath 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 cooled), 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
Howard Keith Henson (born 1942) is an American electrical engineer and writer. Henson writes on subjects including space engineering, space law ( Moon treaty), memetics, cryonics, evolutionary psychology, and the physical limitations of Transh ...
and others has been visualized here
Thermal Space Solar Power concept A related concept is here
Beamed Energy Bootstrapping The proposed radiators are thin wall platic tube filled with low pressure (2.4 kPa) and temperature (20 deg C) steam.
* Solar pumped laser: Japan has pursued a
solar-pumped laser A solar-pumped laser (or solar-powered laser) is a laser that shares the same optics, optical properties as conventional lasers such as emitting a Light beam, beam consisting of Coherence (physics), coherent Electromagnetic radiation, electromagneti ...
, where sunlight directly excites the lasing medium used to create the coherent beam to Earth.
*
Stellaser: A hypothetical concept of a very large laser where a star provides both the lasing energy and the lasing medium, producing a steerable energy beam of unrivaled power.
* 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. Per Paul Werbos, after fusion even neutral particles decay to charged particles which in a sufficiently large volume would allow direct conversion to current.
*
Solar wind loop: Also called a
Dyson–Harrop satellite
A Dyson–Harrop satellite is a hypothetical megastructure intended for power generation using the solar wind. It is inspired by the Dyson sphere
A Dyson sphere is a hypothetical megastructure that completely encompasses a star and captures a ...
. Here the satellite makes use not of the photons from the Sun but rather the charged particles in the solar wind which via electro-magnetic coupling generate a current in a large loop.
* Direct mirrors: Early concepts for direct mirror re-direction of light to planet Earth suffered from the problem that rays coming from the sun are not parallel but are expanding from a disk and so the size of the spot on the Earth is quite large. Lewis Fraas 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 truss, 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 CALTECH's Flying Carpets. For RF designs, an engineering constraint is the
thinned array problem.
* Free floating components:
Solaren 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: Young Bae 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 GHz to a rectenna on the ground. Controversy exists between the benefits of Klystrons, Gyrotrons, 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 clouds and 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 (whether in orbit or on a planet such as
Mercury
Mercury commonly refers to:
* Mercury (planet), the nearest planet to the Sun
* Mercury (element), a metallic chemical element with the symbol Hg
* Mercury (mythology), a Roman god
Mercury or The Mercury may also refer to:
Companies
* Merc ...
) 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
Nuclear safety is defined by the International Atomic Energy Agency (IAEA) as "The achievement of proper operating conditions, prevention of accidents or mitigation of accident consequences, resulting in protection of workers, the public and the ...
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 designs 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 >99% of materials from lunar regolith with very small inputs of "vitamins" from other locations. Using materials from the Moon is attractive because launch 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 aeroshell and survive vibration, pressure and temperature loads. Launch may be via a magnetic mass driver and bypass the requirement to use propellant for launch entirely. Launch 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-Webber 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 SpiderFab 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 well-understood chemical rockets (usually fully reusable launch systems) to LEO, 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:
* Lunar chemical launch: ULA has recently showcased a concept for a fully re-usable chemical lander XEUS to move materials from the Lunar surface to LLO or GEO.
* Lunar
mass driver
A mass driver or electromagnetic catapult is a proposed method of non-rocket spacelaunch which would use a linear motor to Acceleration, accelerate and catapult Payload (air and space craft), payloads up to high speeds. Existing and contemplated ...
: Launch of materials from the lunar surface using a system similar to an aircraft carrier electromagnetic catapult. An unexplored compact alternative would be the slingatron.
*
Lunar space elevator
A lunar space elevator or lunar spacelift is a proposed transportation system for moving a mechanical climbing vehicle up and down a ribbon-shaped tethered cable that is set between the surface of the Moon "at the bottom" and a docking port suspe ...
: 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 space elevator, also referred to as a space bridge, star ladder, and orbital lift, is a proposed type of planet-to-space transportation system, often depicted in science fiction. The main component would be a cable (also called a tether) anc ...
: 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.
* MEO Skyhook: As part of an AFRL study, Roger Lenard proposed a MEO Skyhook. It appears that a gravity gradient-stabilized tether with its center of mass in MEO can be constructed of available materials. The bottom of the skyhook is close to the atmosphere in a "non-keplerian orbit". A re-usable rocket can launch to match altitude and speed with the bottom of the tether which is in a non-keplerian orbit (travelling 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
Maglev (derived from '' magnetic levitation''), is a system of train transportation that uses two sets of electromagnets: one set to repel and push the train up off the track, and another set to move the elevated train ahead, taking advantage ...
launch /
StarTram
StarTram is a proposed space launch system propelled by maglev. The initial Generation 1 facility would launch cargo only, launching from a mountain peak at an altitude of with an evacuated tube staying at local surface level; it has been clai ...
: 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 on-board rocket circularizes the payload.
* Beamed energy launch:
Kevin Parkin and
Escape Dynamics both have concepts for ground-based irradiation of a mono-propellant launch vehicle using RF energy. The RF energy is absorbed and directly heats the propellant not unlike in NERVA-style nuclear-thermal. LaserMotive has a concept for a laser-based approach.
In fiction
Space stations transmitting solar power have appeared in science-fiction works like
Isaac Asimov
yi, יצחק אזימאװ
, birth_date =
, birth_place = Petrovichi, Russian SFSR
, spouse =
, relatives =
, children = 2
, death_date =
, death_place = Manhattan, New York City, U.S.
, nationality = Russian (1920–1922)Soviet (192 ...
's "
Reason
Reason is the capacity of consciously applying logic by drawing conclusions from new or existing information, with the aim of seeking the truth. It is closely associated with such characteristically human activities as philosophy, science, ...
" (1941), that centers around the troubles caused by
the robots operating the station. Asimov's short story "
The Last Question
"The Last Question" is a science fiction short story by American writer Isaac Asimov. It first appeared in the November 1956 issue of Science Fiction Quarterly and was anthologized in the collections Nine Tomorrows (1959), The Best of Isaac A ...
" also features the use of SBSP to provide limitless energy for use on Earth.
Erc Kotani and John Maddox Roberts's 2000 novel ''The Legacy of Prometheus'' posits a race between several conglomerates to be
the first to beam down a gigawatt of energy from a solar satellite in geosynchronous orbit.
In
Ben Bova
Benjamin William Bova (November 8, 1932November 29, 2020) was an American writer and editor. During a writing career of 60 years, he was the author of more than 120 works of science fact and fiction, an editor of '' Analog Science Fiction and F ...
's novel ''PowerSat'' (2005), an entrepreneur strives to prove that his company's nearly completed power satellite and
spaceplane
A spaceplane is a vehicle that can fly and glide like an aircraft in Earth's atmosphere and maneuver like a spacecraft in outer space. To do so, spaceplanes must incorporate features of both aircraft and spacecraft. Orbital spaceplanes ten ...
(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.
[https://www.youtube.com/watch?v=uxftPmpt7aA CIS-Lunar 1000]
The solar satellite is one of three means of producing energy in the browser-based game
OGame
''OGame'' is a browser-based, money-management and space-war themed massively multiplayer online browser game with over two million accounts. OGame was created in 2002 and is produced and maintained by Gameforge. OGame is available in multiple la ...
. The city building game
SimCity 2000
''SimCity 2000'' is a city-building simulation video game jointly developed by Will Wright and Fred Haslam of Maxis. It is the successor to '' SimCity Classic'' and was released for Apple Macintosh personal computers in 1993, after which it wa ...
also features a Microwave Power Plant.
In the 1978 anime TV series ''
Future Boy Conan
, also known as ''Conan, The Boy in Future'', is a Japanese post-apocalyptic science fiction anime series. It is an adaptation of American science-fiction writer Alexander Key's 1970 novel ''The Incredible Tide''. It was broadcast for twent ...
'', SBSP enables the country of Industria to develop geomagnetic weapons, more powerful than
nuclear weapons
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission bomb) or a combination of fission and fusion reactions (thermonuclear bomb), producing a nuclear explosion. Both bomb ...
, that destroy entire continents.
See also
*
Attitude control
Attitude control is the process of controlling the orientation of an aerospace vehicle with respect to an inertial frame of reference or another entity such as the celestial sphere, certain fields, and nearby objects, etc.
Controlling vehicle ...
*
Climate engineering
Climate engineering (also called geoengineering) is a term used for both carbon dioxide removal (CDR) and solar radiation management (SRM), also called solar geoengineering, when applied at a planetary scale.IPCC (2022Chapter 1: Introduction and F ...
*
Future energy development
Energy development is the field of activities focused on obtaining sources of energy from natural resources. These activities include production of renewable, nuclear, and fossil fuel derived sources of energy, and for the recovery and reuse ...
*
Friis transmission equation
The Friis transmission formula is used in telecommunications engineering, equating the power at the terminals of a receive antenna as the product of power density of the incident wave and the effective aperture of the receiving antenna under i ...
*
Orbital station-keeping in GEO
*
*
Solar panels on spacecraft
Spacecraft operating in the inner Solar System usually rely on the use of power electronics-managed photovoltaic solar panels to derive electricity from sunlight. Outside the orbit of Jupiter, solar radiation is too weak to produce sufficient pow ...
*
*
Space mirror
*
*
References
The
National Space Society
The National Space Society (NSS) is an American international nonprofit 501(c)(3) educational and scientific organization specializing in space advocacy. It is a member of the Independent Charities of America and an annual participant in the Combi ...
maintains an extensiv
space solar power library of all major historical documents and studies associated with space solar power, an
major news articles
External links
European Space Agency (ESA) – Advanced Concepts Team, Space-based solar powerWilliam Maness on why alternative energy and power grids aren't good playmates and his plans for beaming solar power from space.in
Seed (magazine)
''Seed'' (subtitled ''Science Is Culture''; originally ''Beneath the Surface'') is a defunct online science magazine published by Seed Media Group. The magazine looked at big ideas in science, important issues at the intersection of science and s ...
The World Needs Energy from SpaceSpace-based solar technology is the key to the world's energy and environmental future, writes
Peter E. Glaser, a pioneer of the technology.
Reinventing the Solar Power Satellite" NASA 2004–212743, report by
Geoffrey A. Landis of NASA Glenn Research Center
Japan's plans for a solar power station in space- the Japanese government hopes to assemble a space-based solar array by 2040.
Space Energy, Inc.- Space Energy, Inc.
Whatever happened to solar power satellites?An article that covers the hurdles in the way of deploying a solar power satellite.
Provides an overview of the technological and political developments needed to construct and utilize a multi-gigawatt power satellite. Also provides some perspective on the cost savings achieved by using
extraterrestrial materials
Extraterrestrial material refers to natural objects now on Earth that originated in outer space. Such materials include cosmic dust and meteorites, as well as samples brought to Earth by sample return missions from the Moon, asteroids and comets, ...
in the construction of the satellite.
A renaissance for space solar power? by Jeff Foust, Monday, August 13, 2007Reports on renewed institutional interest in SSP, and a lack of such interest in past decades.
"Conceptual Study of A Solar Power Satellite, SPS 2000"Makoto Nagatomo, Susumu Sasaki and Yoshihiro Naruo
(
Wired
''Wired'' (stylized as ''WIRED'') is a monthly American magazine, published in print and online editions, that focuses on how emerging technologies affect culture, the economy, and politics. Owned by Condé Nast, it is headquartered in San Fra ...
Science)
The
National Space Society
The National Space Society (NSS) is an American international nonprofit 501(c)(3) educational and scientific organization specializing in space advocacy. It is a member of the Independent Charities of America and an annual participant in the Combi ...
's Space Solar Power Library
The future of Energy is on demand?Special Session at the 2010 ''Festival delle Città Impresa'' featuring John Mankins (Artemis Innovation Management Solutions LLC, USA), Nobuyuki Kaya (
Kobe University
, also known in the Kansai region as , is a leading Japanese national university located in the city of Kobe, in Hyōgo Prefecture, Hyōgo. It was established in 1949, but the academic origins of Kobe University trace back to the establishment of ...
, Japan), Sergio Garribba (
Ministry of Economic Development, Italy), Lorenzo Fiori (
Finmeccanica
Leonardo S.p.A., formerly Leonardo-Finmeccanica and originally Finmeccanica, is an Italian Multinational corporation, multinational company specialising in Aerospace manufacturer, aerospace, arms industry, defence and Information security, securi ...
Group, Italy), Andrea Massa (
University of Trento
The University of Trento (Italian: ''Università degli Studi di Trento'') is an Italian university located in Trento and nearby Rovereto. It has been able to achieve considerable results in didactics, research, and international relations accor ...
, Italy) and Vincenzo Gervasio (
Consiglio Nazionale dell'Economia ed del Lavoro, Italy)
White Paper History of SPS Developpements
International Union of Radio Science
The International Union of Radio Science (abbreviated ''URSI'', after its French name, french: link=no, Union radio-scientifique internationale) is one of 26 international scientific unions affiliated to the International Council for Science ( ...
2007
International SunSat design competitionA simulation of AM reception from an aerial powering two inductive loads and recharging a battery.
Videos
Solar power from space5-minute video about space-based solar power plants by the European Space Agency
Powering the Planet20-minute streaming video from The Futures Channel that provides a "101" on space-based solar power
Space Solar PowerNewSpace 2010 Panel, 72 minutes
Space Solar Power and Space Energy SystemsSSI – Space Manufacturing 14 Panel – 2010 – 27 min
NASA DVD in 16 PartsExploring New Frontiers for Tomorrow's Energy Needs
Space Solar PowerPress Conference September 12, 2008 (71 minutes)
National Space Society
The National Space Society (NSS) is an American international nonprofit 501(c)(3) educational and scientific organization specializing in space advocacy. It is a member of the Independent Charities of America and an annual participant in the Combi ...
BBC One - Bang Goes the Theory, Series 6, Episode 5, Transmitting power without wiresBBC/Lighthouse DEV Eye-safe Laser Based Power Beaming Demo
{{DEFAULTSORT:Space-Based Solar Power
Photovoltaics
Space technology
Thermodynamics
Energy conversion
Satellites
Electric power
Solar power
Solar power and space
Solar power
Solar power is the conversion of energy from sunlight into electricity, either directly using photovoltaics (PV) or indirectly using concentrated solar power. Photovoltaic cells convert light into an electric current using the photovoltaic e ...