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Friday, July 15, 2022

Herbal

From Wikipedia, the free encyclopedia

Dioscorides' De Materia Medica, Byzantium, 15th-century manuscript, by which time the text had been in circulation for about 1500 years

A herbal is a book containing the names and descriptions of plants, usually with information on their medicinal, tonic, culinary, toxic, hallucinatory, aromatic, or magical powers, and the legends associated with them. A herbal may also classify the plants it describes, may give recipes for herbal extracts, tinctures, or potions, and sometimes include mineral and animal medicaments in addition to those obtained from plants. Herbals were often illustrated to assist plant identification.

Herbals were among the first literature produced in Ancient Egypt, China, India, and Europe as the medical wisdom of the day accumulated by herbalists, apothecaries and physicians. Herbals were also among the first books to be printed in both China and Europe. In Western Europe herbals flourished for two centuries following the introduction of moveable type (c. 1470–1670).

In the late 17th century, the rise of modern chemistry, toxicology and pharmacology reduced the medicinal value of the classical herbal. As reference manuals for botanical study and plant identification herbals were supplanted by Floras – systematic accounts of the plants found growing in a particular region, with scientifically accurate botanical descriptions, classification, and illustrations. Herbals have seen a modest revival in the Western world since the last decades of the 20th century, as herbalism and related disciplines (such as homeopathy and aromatherapy) became popular forms of alternative medicine.

History

The word herbal is derived from the mediaeval Latin liber herbalis ("book of herbs"): it is sometimes used in contrast to the word florilegium, which is a treatise on flowers with emphasis on their beauty and enjoyment rather than the herbal emphasis on their utility. Much of the information found in printed herbals arose out of traditional medicine and herbal knowledge that predated the invention of writing.

Before the advent of printing, herbals were produced as manuscripts, which could be kept as scrolls or loose sheets, or bound into codices. Early handwritten herbals were often illustrated with paintings and drawings. Like other manuscript books, herbals were "published" through repeated copying by hand, either by professional scribes or by the readers themselves. In the process of making a copy, the copyist would often translate, expand, adapt, or reorder the content. Most of the original herbals have been lost; many have survived only as later copies (of copies...), and others are known only through references from other texts.

As printing became available, it was promptly used to publish herbals, the first printed matter being known as incunabula. In Europe, the first printed herbal with woodcut (xylograph) illustrations, the Puch der Natur of Konrad of Megenberg, appeared in 1475. Metal-engraved plates were first used in about 1580. As woodcuts and metal engravings could be reproduced indefinitely they were traded among printers: there was therefore a large increase in the number of illustrations together with an improvement in quality and detail but a tendency for repetition.

As examples of some of the world's most important records and first printed matter, a researcher will find herbals scattered through the world's most famous libraries including the Vatican Library in Rome, the Bodleian Library in Oxford, the Royal Library in Windsor, the British Library in London and the major continental libraries.

China, India, Mexico

Shen Nung Pen Ts’ao ching of China

China is renowned for its traditional herbal medicines that date back thousands of years. Legend has it that mythical Emperor Shennong, the founder of Chinese herbal medicine, composed the Shennong Bencao Jing or Great Herbal in about 2700 BCE as the forerunner of all later Chinese herbals. It survives as a copy made c. 500 CE and describes about 365 herbs. High quality herbals and monographs on particular plants were produced in the period to 1250 CE including: the Zhenlei bencao written by Tang Shenwei in 1108, which passed through twelve editions until 1600; a monograph on the lychee by Cai Xiang in 1059 and one on the oranges of Wenzhhou by Han Yanzhi in 1178. In 1406 Ming dynasty prince Zhu Xiao (朱橚) published the Jiuhuang Bencao illustrated herbal for famine foods. It contained high quality woodcuts and descriptions of 414 species of plants of which 276 were described for the first time, the book pre-dating the first European printed book by 69 years. It was reprinted many times. Other herbals include Bencao Fahui in 1450 by Xu Yong and Bencao Gangmu of Li Shizhen in 1590.

Sushruta Samhita of India

Traditional herbal medicine of India, known as Ayurveda, possibly dates back to the second millennium BCE tracing its origins to the holy Hindu Vedas and, in particular, the Atharvaveda. One authentic compilation of teachings is by the surgeon Sushruta, available in a treatise called Sushruta Samhita. This contains 184 chapters and description of 1120 illnesses, 700 medicinal plants, 64 preparations from mineral sources and 57 preparations based on animal sources. Other early works of Ayurveda include the Charaka Samhita, attributed to Charaka. This tradition, however is mostly oral. The earliest surviving written material which contains the works of Sushruta is the Bower Manuscript—dated to the 4th century CE.

Hernandez – Rerum Medicarum and the Aztecs

An illustrated herbal published in Mexico in 1552, Libellus de Medicinalibus Indorum Herbis ("Book of Medicinal Herbs of the Indies"), is written in the Aztec Nauhuatl language by a native physician, Martín Cruz. This is probably an extremely early account of the medicine of the Aztecs although the formal illustrations, resembling European ones, suggest that the artists were following the traditions of their Spanish masters rather than an indigenous style of drawing. In 1570 Francisco Hernández (c.1514–1580) was sent from Spain to study the natural resources of New Spain (now Mexico). Here he drew on indigenous sources, including the extensive botanical gardens that had been established by the Aztecs, to record c. 1200 plants in his Rerum Medicarum of 1615. Nicolás MonardesDos Libros (1569) contains the first published illustration of tobacco.

Egypt, Mesopotamia, Greece and Rome

Statue of Theophrastus c. 371 – c. 287 BCE, Orto botanico di Palermo
 

By about 2000 BCE, medical papyri in ancient Egypt included medical prescriptions based on plant matter and made reference to the herbalist's combination of medicines and magic for healing.[31]

Papyrus Ebers

A page from the Ebers Papyrus, the most complete and extensive of surviving ancient herbals

The ancient Egyptian Papyrus Ebers is one of the earliest known herbals; it dates to 1550 BCE and is based on sources, now lost, dating back a further 500 to 2000 years. The earliest Sumerian herbal dates from about 2500 BCE as a copied manuscript of the 7th century BCE. Inscribed Assyrian tablets dated 668–626 BCE list about 250 vegetable drugs: the tablets include herbal plant names that are still in use today including: saffron, cumin, turmeric and sesame.

The ancient Greeks gleaned much of their medicinal knowledge from Egypt and Mesopotamia. Hippocrates (460–377 BCE), the "father of medicine" (renowned for the eponymous Hippocratic oath), used about 400 drugs, most being of plant origin. However, the first Greek herbal of any note was written by Diocles of Carystus in the fourth century BC—although nothing remains of this except its mention in the written record. It was Aristotle’s pupil Theophrastus (371–287 BCE) in his Historia Plantarum, (better known as the Enquiry into Plants) and De Causis Plantarum (On the Causes of Plants) that established the scientific method of careful and critical observation associated with modern botanical science. Based largely on Aristotle’s notes, the Ninth Book of his Enquiry deals specifically with medicinal herbs and their uses including the recommendations of herbalists and druggists of the day, and his plant descriptions often included their natural habitat and geographic distribution. With the formation of the Alexandrian School c. 330 BCE medicine flourished and written herbals of this period included those of the physicians Herophilus, Mantias, Andreas of Karystos, Appolonius Mys, and Nicander. The work of rhizomatist (the rhizomati were the doctors of the day, berated by Theophrastus for their superstition) Krateuas (fl. 110 BCE) is of special note because he initiated the tradition of the illustrated herbal in the first century BCE.

Dioscorides – De Materia Medica

Arabic Book of Simple Drugs (c. 1334) from Dioscorides’ De Materia Medica. British Museum
 

The De Materia Medica (c. 40–90 CE; Greek, Περί ύλης ιατρικής "Peri hules iatrikes", 'On medical materials') of Pedanios Dioscorides, a physician in the Roman army, was produced in about 65 CE. It was the single greatest classical authority on the subject and the most influential herbal ever written, serving as a model for herbals and pharmacopoeias, both oriental and occidental, for the next 1000 years up to the Renaissance. It drew together much of the accumulated herbal knowledge of the time, including some 500 medicinal plants. The original has been lost but a lavishly illustrated Byzantine copy known as the Vienna Dioscurides dating from about 512 CE remains.

Pliny – Natural History

Pliny the Elder's (23–79 CE) encyclopaedic Natural History (c. 77–79 CE) is a synthesis of the information contained in about 2000 scrolls and it includes myths and folklore; there are about 200 extant copies. It comprises 37 books of which sixteen (Books 12–27) are devoted to trees, plants and medicaments and, of these, seven describe medicinal plants. In medieval herbals, along with De Materia Medica it is Pliny's work that is the most frequently mentioned of the classical texts, even though Galen's (131–201 CE) De Simplicibus is more detailed. Another Latin translation of Greek works that was widely copied in the Middle Ages, probably illustrated in the original, was that attributed to Apuleius: it also contained the alternative names for particular plants given in several languages. It dates to about 400 CE and a surviving copy dates to about 600 CE.

The Middle Ages and Arab World

During the 600 years of the European Middle Ages from 600 to 1200, the tradition of herbal lore fell to the monasteries. Many of the monks were skilled at producing books and manuscripts and tending both medicinal gardens and the sick, but written works of this period simply emulated those of the classical era.

Meanwhile, in the Arab world, by 900 the great Greek herbals had been translated and copies lodged in centres of learning in the Byzantine empire of the eastern Mediterranean including Byzantium, Damascus, Cairo and Baghdad where they were combined with the botanical and pharmacological lore of the Orient. In the medieval Islamic world, Muslim botanists and Muslim physicians made a major contribution to the knowledge of herbal medicines. Those associated with this period include Mesue Maior (Masawaiyh, 777–857) who, in his Opera Medicinalia, synthesised the knowledge of Greeks, Persians, Arabs, Indians and Babylonians, this work was complemented by the medical encyclopaedia of Avicenna (Ibn Sina, 980–1037). Avicenna's Canon of Medicine was used for centuries in both East and West. During this period Islamic science protected classical botanical knowledge that had been ignored in the West and Muslim pharmacy thrived.

Albertus Magnus – De Vegetabilibus

Albertus Magnus c. 1193–1280, author of De Vegetabilibus
 

In the thirteenth century, scientific inquiry was returning and this was manifest through the production of encyclopaedias; those noted for their plant content included a seven volume treatise by Albertus Magnus (c. 1193–1280) a Suabian educated at the University of Padua and tutor to St Thomas Aquinas. It was called De Vegetabilibus (c. 1256 AD) and even though based on original observations and plant descriptions it bore a close resemblance to the earlier Greek, Roman and Arabic herbals. Other accounts of the period include De Proprietatibus Rerum (c. 1230–1240) of English Franciscan friar Bartholomaeus Anglicus and a group of herbals called Tractatus de Herbis written and painted between 1280 and 1300 by Matthaeus Platearius at the East-West cultural centre of Salerno Spain, the illustrations showing the fine detail of true botanical illustration.

Western Europe

Illustration from Elizabeth Blackwell's A Curious Herbal (1737)

Perhaps the best known herbals were produced in Europe between 1470 and 1670. The invention in Germany of printing from movable type in a printing press c. 1440 was a great stimulus to herbalism. The new herbals were more detailed with greater general appeal and often with Gothic script and the addition of woodcut illustrations that more closely resembled the plants being described.

Three important herbals, all appearing before 1500, were printed in Mainz, Germany. Two of these were by Peter Schoeffer, his Latin Herbarius in 1484, followed by an updated and enlarged German version in 1485, these being followed in 1491 by the Hortus Sanitatis printed by Jacob Meyderbach. Other early printed herbals include the Kreuterbuch of Hieronymus Tragus from Germany in 1539 and, in England, the New Herball of William Turner in 1551 were arranged, like the classical herbals, either alphabetically, according to their medicinal properties, or as "herbs, shrubs, trees". Arrangement of plants in later herbals such as Cruydboeck of Dodoens and John Gerard's Herball of 1597 became more related to their physical similarities and this heralded the beginnings of scientific classification. By 1640 a herbal had been printed that included about 3800 plants – nearly all the plants of the day that were known.

In the Modern Age and Renaissance, European herbals diversified and innovated, and came to rely more on direct observation than being mere adaptations of traditional models. Typical examples from the period are the fully illustrated De Historia Stirpium Commentarii Insignes by Leonhart Fuchs (1542, with over 400 plants), the astrologically themed Complete Herbal by Nicholas Culpeper (1653), and the Curious Herbal by Elizabeth Blackwell (1737).

Anglo-Saxon herbals

Anglo-Saxon plant knowledge and gardening skills (the garden was called a wyrtzerd, literally, herb-yard) appears to have exceeded that on the continent. Our limited knowledge of Anglo-Saxon plant vernacular comes primarily from manuscripts that include: the Leechbook of Bald and the Lacnunga. The Leechbook of Bald (Bald was probably a friend of King Alfred of England) was painstakingly produced by the scribe Cild in about 900–950 CE. This was written in the vernacular (native) tongue and not derived from Greek texts. The oldest illustrated herbal from Saxon times is a translation of the Latin Herbarius Apulei Platonici, one of the most popular medical works of medieval times, the original dating from the fifth century; this Saxon translation was produced about 1000–1050 CE and is housed in the British Library. Another vernacular herbal was the Buch der natur or "Book of Nature" by Konrad von Megenberg (1309–1374) which contains the first two botanical woodcuts ever made; it is also the first work of its kind in the vernacular.

Anglo-Norman herbals

In the 12th and early 13th centuries, under the influence of the Norman conquest, the herbals produced in Britain fell less under the influence of France and Germany and more that of Sicily and the Near East. This showed itself through the Byzantine-influenced Romanesque framed illustrations. Anglo-Saxon herbals in the vernacular were replaced by herbals in Latin including Macers Herbal, De Viribus Herbarum (largely derived from Pliny), with the English translation completed in about 1373.

Fifteenth-century incunabula

The earliest printed books and broadsheets are known as incunabula. The first printed herbal appeared in 1469, a version of Pliny's Historia Naturalis; it was published nine years before Dioscorides De Materia Medica was set in type. Important incunabula include the encyclopaedic De Proprietatibus Rerum of Franciscan friar Bartholomew Anglicus (c. 1203–1272) which, as a manuscript, had first appeared between 1248 and 1260 in at least six languages and after being first printed in 1470 ran to 25 editions. Assyrian physician Mesue (926–1016) wrote the popular De Simplicibus, Grabadin and Liber Medicinarum Particularum the first of his printings being in 1471. These were followed, in Italy, by the Herbarium of Apuleius Platonicus and three German works published in Mainz, the Latin Herbarius (1484), the first herbal published in Germany, German Herbarius (1485), the latter evolving into the Ortus Sanitatis (1491). To these can be added Macer’s De Virtutibus Herbarum, based on Pliny's work; the 1477 edition is one of the first printed and illustrated herbals.

Fifteenth-century manuscripts

In medieval times, medicinal herbs were generally referred to by the apothecaries (physicians or doctors) as "simples" or "officinals". Before 1542, the works principally used by apothecaries were the treatises on simples by Avicenna and Serapion’s Liber De Simplici Medicina. The De Synonymis and other publications of Simon Januensis, the Liber Servitoris of Bulchasim Ben Aberazerim, which described the preparations made from plants, animals and minerals, provided a model for the chemical treatment of modern pharmacopoeias. There was also the Antidotarium Nicolai of Nicolaus de Salerno, which contained Galenical compounds arranged in alphabetical order.

Spain and Portugal – de Orta, Monardes, Hernandez

The Spaniards and Portuguese were explorers, the Portuguese to India (Vasco da Gama) and Goa where physician Garcia de Orta (1490–1570) based his work Coloquios dos Simples (1563). The first botanical knowledge of the New World came from Spaniard Nicolas Monardes (1493–1588) who published Dos Libros between 1569 and 1571. The work of Hernandez on the herbal medicine of the Aztecs has already been discussed.

Germany – Bock, Brunfels and Fuchs

A Hans Weiditz hand-coloured woodcut from Otto Brunfels' Herbarum Vivae Eicones

Otto Brunfels (c. 1489–1534), Leonhart Fuchs (1501–1566) and Hieronymus Bock (1498–1554) were known as the "German fathers of botany" although this title belies the fact that they trod in the steps of the scientifically feted Hildegard of Bingen whose writings on herbalism were Physica and Causae et Curae (together known as Liber subtilatum) of 1150. The original manuscript is no longer in existence but a copy was printed in 1533. Another major herbalist was Valerius Cordus (1515–1544).

The 1530, Herbarum Vivae Eicones of Brunfels contained the admired botanically accurate original woodcut colour illustrations of Hans Weiditz along with descriptions of 47 species new to science. Bock, in setting out to describe the plants of his native Germany, produced the New Kreuterbuch of 1539 describing the plants he had found in the woods and fields but without illustration; this was supplemented by a second edition in 1546 that contained 365 woodcuts. Bock was possibly the first to adopt a botanical classification in his herbal which also covered details of ecology and plant communities. In this, he was placing emphasis on botanical rather than medicinal characteristics, unlike the other German herbals and foreshadowing the modern Flora. De Historia Stirpium (1542 with a German version in 1843) of Fuchs was a later publication with 509 high quality woodcuts that again paid close attention to botanical detail: it included many plants introduced to Germany in the sixteenth century that were new to science. The work of Fuchs is regarded as being among the most accomplished of the Renaissance period.

Low Countries – Dodoens, Lobel, Clusius

The Flemish printer Christopher Plantin established a reputation publishing the works of Dutch herbalists Rembert Dodoens and Carolus Clusius and developing a vast library of illustrations. Translations of early Greco-Roman texts published in German by Bock in 1546 as Kreuterbuch were subsequently translated into Dutch as Pemptades by Dodoens (1517–1585) who was a Belgian botanist of world renown. This was an elaboration of his first publication Cruydeboeck (1554). Matthias de Lobel (1538–1616) published his Stirpium Adversaria Nova (1570–1571) and a massive compilation of illustrations while Clusius's (1526–1609) magnum opus was Rariorum Plantarum Historia of 1601 which was a compilation of his Spanish and Hungarian floras and included over 600 plants that were new to science.

Italy – Mattioli, Calzolari, Alpino

Early Italian manuscript herbal, c. 1500. Plants illustrated are Appolinaris, Chamomeleon, Sliatriceo and Narcissus

In Italy, two herbals were beginning to include botanical descriptions. Notable herbalists included Pietro Andrea Mattioli (1501–1577), physician to the Italian aristocracy and his Commentarii (1544), which included many newly described species, and his more traditional herbal Epistolarum Medicinalium Libri Quinque (1561). Sometimes, the local flora was described as in the publication Viaggio di Monte Baldo (1566) of Francisco Calzolari. Prospero Alpini (1553–1617) published in 1592 the highly popular account of overseas plants De Plantis Aegypti and he also established a botanical garden in Padua in 1542, which together with those at Pisa and Florence, rank among the world's first.

England – Turner, Gerard, Parkinson, Culpeper

The first true herbal printed in Britain was Richard Banckes' Herball of 1525 which, although popular in its day, was unillustrated and soon eclipsed by the most famous of the early printed herbals, Peter Treveris's Grete Herball of 1526 (derived in turn from the derivative French Grand Herbier).

An engraving of Parkinson from his work Theatrum Botanicum (1640), reprinted in Agnes Arber's Herbals

William Turner (?1508–7 to 1568) was an English naturalist, botanist, and theologian who studied at Cambridge University and eventually became known as the “father of English botany." His 1538 publication Libellus de re Herbaria Novus was the first essay on scientific botany in English. His three-part A New Herball of 1551–1562–1568, with woodcut illustrations taken from Fuchs, was noted for its original contributions and extensive medicinal content; it was also more accessible to readers, being written in vernacular English. Turner described over 200 species native to England. and his work had a strong influence on later eminent botanists such as John Ray and Jean Bauhin.

John Gerard (1545–1612) is the most famous of all the English herbalists. His Herball of 1597 is, like most herbals, largely derivative. It appears to be a reformulation of Hieronymus Bock's Kreuterbuch subsequently translated into Dutch as Pemptades by Rembert Dodoens (1517–1585), and thence into English by Carolus Clusius, (1526–1609) then re-worked by Henry Lyte in 1578 as A Nievve Herball. This became the basis of Gerard's Herball or General Historie of Plantes. that appeared in 1597 with its 1800 woodcuts (only 16 original). Although largely derivative, Gerard's popularity can be attributed to his evocation of plants and places in Elizabethan England and to the clear influence of gardens and gardening on this work. He had published, in 1596, Catalogus which was a list of 1033 plants growing in his garden.

John Parkinson (1567–1650) was apothecary to James I and a founding member of the Worshipful Society of Apothecaries. He was an enthusiastic and skilful gardener, his garden in Long Acre being stocked with rarities. He maintained an active correspondence with important English and Continental botanists, herbalists and plantsmen importing new and unusual plants from overseas, in particular the Levant and Virginia. Parkinson is celebrated for his two monumental works, the first Paradisi in Sole Paradisus Terrestris in 1629: this was essentially a gardening book, a florilegium for which Charles I awarded him the title Botanicus Regius Primarius – Royal Botanist. The second was his Theatrum Botanicum of 1640, the largest herbal ever produced in the English language. It lacked the quality illustrations of Gerard's works, but was a massive and informative compendium including about 3800 plants (twice the number of Gerard's first edition Herball), over 1750 pages and over 2,700 woodcuts. This was effectively the last and culminating herbal of its kind and, although it included more plants of no discernible economic or medicinal use than ever before, they were nevertheless arranged according to their properties rather than their natural affinities.

Nicholas Culpeper (1616–1654) was an English botanist, herbalist, physician, apothecary and astrologer from London's East End. His published books were A Physicall Directory (1649), which was a pseudoscientific pharmacopoeia. The English Physitian (1652) and the Complete Herbal (1653), contain a rich store of pharmaceutical and herbal knowledge. His works lacked scientific credibility because of their use of astrology, though he combined diseases, plants and astrological prognosis into a simple integrated system that has proved popular to the present day.

Legacy

Back cover of the Chinese pharmacopoeia (1930)

The legacy of the herbal extends beyond medicine to botany and horticulture. Herbal medicine is still practiced in many parts of the world but the traditional grand herbal, as described here, ended with the European Renaissance, the rise of modern medicine and the use of synthetic and industrialized drugs. The medicinal component of herbals has developed in several ways. Firstly, discussion of plant lore was reduced and with the increased medical content there emerged the official pharmacopoeia. The first British Pharmacopoeia was published in the English language in 1864, but gave such general dissatisfaction both to the medical profession and to chemists and druggists that the General Medical Council brought out a new and amended edition in 1867. Secondly, at a more popular level, there are the books on culinary herbs and herb gardens, medicinal and useful plants. Finally, the enduring desire for simple medicinal information on specific plants has resulted in contemporary herbals that echo the herbals of the past, an example being Maud Grieve's A Modern Herbal, first published in 1931 but with many subsequent editions.

Illustration of Delphinium peregrinum in Flora Graeca by John Sibthorp and Ferdinand Bauer (1806–1840)

The magical and mystical side of the herbal also lives on. Herbals often explained plant lore, displaying a superstitious or spiritual side. There was, for example, the fanciful doctrine of signatures, the belief that there were similarities in the appearance of the part of the body affected the appearance of the plant to be used as a remedy. The astrology of Culpeper can be seen in contemporary anthroposophy (biodynamic gardening) and alternative medical approaches like homeopathy, aromatherapy and other new age medicine show connections with herbals and traditional medicine.

It is sometimes forgotten that the plants described in herbals were grown in special herb gardens (physic gardens). Such herb gardens were, for example, part of the medieval monastery garden that supplied the simples or officinals used to treat the sick being cared for within the monastery. Early physic gardens were also associated with institutes of learning, whether a monastery, university or herbarium. It was this medieval garden of the fourteenth to sixteenth centuries, attended by apothecaries and physicians, that established a tradition leading to the systems gardens of the eighteenth century (gardens that demonstrated the classification system of plants) and the modern botanical garden. The advent of printing, woodcuts and metal engraving improved the means of communication. Herbals prepared the ground for modern botanical science by pioneering plant description, classification and illustration. From the time of the ancients like Dioscorides through to Parkinson in 1629, the scope of the herbal remained essentially the same.

The greatest legacy of the herbal is to botany. Up to the seventeenth century, botany and medicine were one and the same but gradually greater emphasis was placed on the plants rather than their medicinal properties. During the seventeenth and eighteenth centuries, plant description and classification began to relate plants to one another and not to man. This was the first glimpse of non-anthropocentric botanical science since Theophrastus and, coupled with the new system of binomial nomenclature, resulted in "scientific herbals" called Floras that detailed and illustrated the plants growing in a particular region. These books were often backed by herbaria, collections of dried plants that verified the plant descriptions given in the Floras. In this way modern botany, especially plant taxonomy, was born out of medicine. As herbal historian Agnes Arber remarks – "Sibthorp's monumental Flora Graeca is, indeed, the direct descendant in modern science of the De Materia Medica of Dioscorides."

Anarchy

From Wikipedia, the free encyclopedia

Anarchy is a society being freely constituted without authorities or a governing body. It may also refer to a society or group of people that entirely rejects a set hierarchy. Anarchy was first used in English in 1539, meaning "an absence of government". Pierre-Joseph Proudhon adopted anarchy and anarchist in his 1840 treatise What Is Property? to refer to anarchism, a new political philosophy and social movement that advocates stateless societies based on free and voluntary associations. Anarchists seek a system based on the abolition of all coercive hierarchy, in particular the state, and many advocate for the creation of a system of direct democracy and worker cooperatives.

In practical terms, anarchy can refer to the curtailment or abolition of traditional forms of government and institutions. It can also designate a nation or any inhabited place that has no system of government or central rule. Anarchy is primarily advocated by individual anarchists who propose replacing government with voluntary institutions. These institutions or free associations are generally modeled on nature since they can represent concepts such as community and economic self-reliance, interdependence, or individualism. Although anarchy is often negatively used as a synonym of chaos or societal collapse, this is not the meaning that anarchists attribute to anarchy, a society without hierarchies. Proudhon wrote that anarchy is "Not the Daughter But the Mother of Order."

Etymology

Circle-A anarchist symbol

Anarchy comes from the Medieval Latin anarchia and from the Greek anarchos ("having no ruler"), with an + archos ("ruler") literally meaning "without ruler". The circle-A anarchist symbol is a monogram that consists of the capital letter A surrounded by the capital letter O. The letter A is derived from the first letter of anarchy or anarchism in most European languages and is the same in both Latin and Cyrillic scripts. The O stands for order and together they stand for "society seeks order in anarchy" (French: la société cherche l'ordre dans l'anarchie), a phrase written by Pierre-Joseph Proudhon in his 1840 book What Is Property?

Overview

Anthropology

Although most known societies are characterized by the presence of hierarchy or the state, anthropologists have studied many egalitarian stateless societies, including most nomadic hunter-gatherer societies and horticultural societies such as the Semai and the Piaroa. Many of these societies can be considered to be anarchic in the sense that they explicitly reject the idea of centralized political authority.

Hunter-gatherers are considered to be living in an anarchistic society

The egalitarianism typical of human hunter-gatherers is interesting when viewed in an evolutionary context. One of humanity's two closest primate relatives, the chimpanzee, is anything but egalitarian, forming hierarchies that are dominated by alpha males. So great is the contrast with human hunter-gatherers that it is widely argued by palaeoanthropologists that resistance to being dominated was a key factor driving the development of human consciousness, language, kinship and social organization.

In Fragments of an Anarchist Anthropology, anarchist anthropologist David Graeber attempted to outline areas of research that intellectuals might explore in creating a cohesive body of anarchist social theory. Graeber posited that anthropology is "particularly well positioned" as an academic discipline that can look at the gamut of human societies and organizations to study, analyze and catalog alternative social and economic structures around the world, and most importantly, present these alternatives to the world.

In Society Against the State, Pierre Clastres examined stateless societies where certain cultural practices and attitudes avert the development of hierarchy and the state. Clastres dismissed the notion that the state is the natural outcome of the evolution of human societies.

In The Art of Not Being Governed, James C. Scott studied Zomia, a vast stateless upland region on Southeast Asia. The hills of Zomia isolate it from the lowland states and create a refuge for people to escape to. Scott argues that the particular social and cultural characteristics of the hill people were adapted to escape capture by the lowland states and should not be viewed as relics of barbarism abandoned by civilization.

Peter Leeson examined a variety of institutions of private law enforcement developed in anarchic situations by eighteenth century pirates, preliterate tribesmen, and Californian prison gangs. These groups all adapted different methods of private law enforcement to meet their specific needs and the particulars of their anarchic situation.

Anarcho-primitivists base their critique of civilization partly on anthropological studies of nomadic hunter-gatherers, noting that the shift towards domestication has likely caused increases in disease, labor, inequality, warfare and psychological disorders. Authors such as John Zerzan have argued that negative stereotypes of primitive societies (e.g. that they are typically extremely violent or impoverished) are used to justify the values of modern industrial society and to move individuals further away from more natural and equitable conditions.

International relations

In international relations, anarchy is "the absence of any authority superior to nation-states and capable of arbitrating their disputes and enforcing international law".

Political philosophy

Anarchism

As a political philosophy, anarchism advocates self-governed societies based on voluntary institutions. These are often described as stateless societies, although several authors have defined them more specifically as institutions based on non-hierarchical free associations. Anarchism holds the state to be undesirable, unnecessary, or harmful. While opposition to the state is central, it is a necessary but not sufficient condition, hence why, in spite of their names, anarcho-capitalism and national-anarchism are either not recognized as anarchist schools of thought and as part of the anarchist movement, or are seen by anarchists and scholars as fraudulent and an oxymoron. Anarchism entails opposing authority or hierarchical organisation in the conduct of all human relations, including yet not limited to the state system.

There are many types and traditions of anarchism, not all of which are mutually exclusive. Anarchist schools of thought can differ fundamentally, supporting anything from extreme individualism to complete collectivism. Strains of anarchism have been divided into the categories of individualist and social anarchism, or similar dual classifications. Anarchism is often considered to be a radical left-wing or far-left movement and much of anarchist economics and anarchist law reflect anti-authoritarian, anti-statist and libertarian interpretations of left-wing and socialist politics such communism, mutualism and syndicalism, among other libertarian socialist and socialist economics such as collectivist anarchism, free-market anarchism, green anarchism and participatory economics. Within anarchism, some individualist anarchists are communists while some anarcho-communists are egoists or individualists. Where individualist forms of anarchism emphasize personal autonomy and the rational nature of human beings, social anarchism sees "individual freedom as conceptually connected with social equality and emphasize community and mutual aid". In European Socialism: A History of Ideas and Movements, Carl Landauer summarized the difference between communist and individualist anarchists by stating that "the communist anarchists also do not acknowledge any right to society to force the individual. They differ from the anarchistic individualists in their belief that men, if freed from coercion, will enter into voluntary associations of a communistic type, while the other wing believes that the free person will prefer a high degree of isolation".

As a social movement, anarchism has regularly endured fluctuations in popularity. The central tendency of anarchism as a mass social movement has been represented by anarcho-communism and anarcho-syndicalism, with individualist anarchism being primarily a literary phenomenon while social anarchism has been the dominant form of anarchism, emerging in the late 19th century as a distinction from individualist anarchism after anarcho-communism replaced collectivist anarchism as the dominant tendency. Nonetheless, individualist anarchism did influence the bigger currents and individualists also participated in large anarchist organizations. Some anarchists are pacifists who support self-defense or non-violence (anarcho-pacifism) while others have supported the use of militant measures, including revolution and propaganda of the deed, on the path to an anarchist society.

Since the 1890s, libertarianism has been used as a synonym for anarchism and was used almost exclusively in this sense until the mid-20th century development of right-libertarianism in the United States, where classical liberals began to describe themselves as libertarians. It has since become necessary to distinguish their classical liberal individualist and free-market capitalist philosophy from anarchism. The former is often referred to as right-libertarianism whereas the latter is described by as left-libertarianism, libertarian socialism and socialist libertarianism. Examples of Right-libertarian ideologies include anarcho-capitalism, minarchism and voluntaryism. Outside the English-speaking world, libertarianism generally retains its association with anarchism, anti-capitalism, libertarian socialism and social anarchism.

Immanuel Kant

The German philosopher Immanuel Kant treated anarchy in his Anthropology from a Pragmatic Point of View as consisting of "Law and Freedom without Force". For Kant, anarchy falls short of being a true civil state because the law is only an "empty recommendation" if force is not included to make this law efficacious ("legitimation", etymologically fancifully from legem timere, i.e. "fearing the law"). For there to be such a state, force must be included while law and freedom are maintained, a state which Kant calls a republic. Kant identified four kinds of government:

  1. Law and freedom without force (anarchy)
  2. Law and force without freedom (despotism)
  3. Force without freedom and law (barbarism)
  4. Force with freedom and law (republic)

Examples of state-collapse anarchy

English Civil War (1642–1651)

Mainland Europe experienced near-anarchy in the Thirty Years' War (1618–1648)

Anarchy was one of the issues at the Putney Debates of 1647:

Thomas Rainsborough: "I shall now be a little more free and open with you than I was before. I wish we were all true-hearted, and that we did all carry ourselves with integrity. If I did mistrust you I would not use such asseverations. I think it doth go on mistrust, and things are thought too readily matters of reflection, that were never intended. For my part, as I think, you forgot something that was in my speech, and you do not only yourselves believe that some men believe that the government is never correct, but you hate all men that believe that. And, sir, to say because a man pleads that every man hath a voice by right of nature, that therefore it destroys by the same argument all property – this is to forget the Law of God. That there's a property, the Law of God says it; else why hath God made that law, Thou shalt not steal? I am a poor man, therefore I must be oppressed: if I have no interest in the kingdom, I must suffer by all their laws be they right or wrong. Nay thus: a gentleman lives in a country and hath three or four lordships, as some men have (God knows how they got them); and when a Parliament is called he must be a Parliament-man; and it may be he sees some poor men, they live near this man, he can crush them – I have known an invasion to make sure he hath turned the poor men out of doors; and I would fain know whether the potency of rich men do not this, and so keep them under the greatest tyranny that was ever thought of in the world. And therefore I think that to that it is fully answered: God hath set down that thing as to propriety with this law of his, Thou shalt not steal. And for my part I am against any such thought, and, as for yourselves, I wish you would not make the world believe that we are for anarchy."

Oliver Cromwell: "I know nothing but this, that they that are the most yielding have the greatest wisdom; but really, sir, this is not right as it should be. No man says that you have a mind to anarchy, but that the consequence of this rule tends to anarchy, must end in anarchy; for where is there any bound or limit set if you take away this limit, that men that have no interest but the interest of breathing shall have no voice in elections? Therefore, I am confident on’t, we should not be so hot one with another."

As people began to theorize about the English Civil War, anarchy came to be more sharply defined, albeit from differing political perspectives:

  • 1651 – Thomas Hobbes (Leviathan) describes the natural condition of mankind as a war of all against all, where man lives a brutish existence: "For the savage people in many places of America, except the government of small families, the concord whereof dependeth on natural lust, have no government at all, and live at this day in that brutish manner". Hobbes finds three basic causes of the conflict in this state of nature, namely competition, diffidence and glory: "The first maketh men invade for gain; the second, for safety; and the third, for reputation". His first law of nature is that "every man ought to endeavour peace, as far as he has hope of obtaining it; and when he cannot obtain it, that he may seek and use all helps and advantages of war". In the state of nature, "every man has a right to every thing, even to then go for one another's body", but the second law is that in order to secure the advantages of peace "that a man be willing, when others are so too ... to lay down this right to all things; and be contented with so much liberty against other men as he would allow other men against himself". This is the beginning of contracts/covenants; performing of which is the third law of nature. Therefore, injustice is failure to perform in a covenant and all else is just.
  • 1656 – James Harrington (The Commonwealth of Oceana) uses anarchy to describe a situation where the people use force to impose a government on an economic base composed of either solitary land ownership (absolute monarchy), or land in the ownership of a few (mixed monarchy). He distinguishes it from commonwealth, the situation when both land ownership and governance shared by the population at large, seeing it as a temporary situation arising from an imbalance between the form of government and the form of property relations.

French Revolution (1789–1799)

Heads of aristocrats on spikes

Thomas Carlyle, Scottish essayist of the Victorian era known foremost for his widely influential work of history, The French Revolution, wrote that the French Revolution was a war against both aristocracy and anarchy:

Meanwhile, we will hate Anarchy as Death, which it is; and the things worse than Anarchy shall be hated more! Surely Peace alone is fruitful. Anarchy is destruction: a burning up, say, of Shams and Insupportabilities; but which leaves Vacancy behind. Know this also, that out of a world of Unwise nothing but an Unwisdom can be made. Arrange it, Constitution-build it, sift it through Ballot-Boxes as thou wilt, it is and remains an Unwisdom,-- the new prey of new quacks and unclean things, the latter end of it slightly better than the beginning. Who can bring a wise thing out of men unwise? Not one. And so Vacancy and general Abolition having come for this France, what can Anarchy do more? Let there be Order, were it under the Soldier's Sword; let there be Peace, that the bounty of the Heavens be not spilt; that what of Wisdom they do send us bring fruit in its season! – It remains to be seen how the quellers of Sansculottism were themselves quelled, and sacred right of Insurrection was blown away by gunpowder: wherewith this singular eventful History called French Revolution ends.

In 1789, Armand, duc d'Aiguillon came before the National Assembly and shared his views on the anarchy:

I may be permitted here to express my personal opinion. I shall no doubt not be accused of not loving liberty, but I know that not all movements of peoples lead to liberty. But I know that great anarchy quickly leads to great exhaustion and that despotism, which is a kind of rest, has almost always been the necessary result of great anarchy. It is therefore much more important than we think to end the disorder under which we suffer. If we can achieve this only through the use of force by authorities, then it would be thoughtless to keep refraining from using such force.

Armand was later exiled because he was viewed as being opposed to the revolution's violent tactics. Professor Chris Bossche commented on the role of anarchy in the revolution:

In The French Revolution, the narrative of increasing anarchy undermined the narrative in which the revolutionaries were striving to create a new social order by writing a constitution.

Jamaica (1720)

In 1720, Sir Nicholas Lawes, Governor of Jamaica, wrote to John Robinson, the Bishop of London:

As to the Englishmen that came as mechanics hither, very young and have now acquired good estates in Sugar Plantations and Indigo & co., of course they know no better than what maxims they learn in the Country. To be now short & plain Your Lordship will see that they have no maxims of Church and State but what are absolutely anarchical.

In the letter, Lawes goes on to complain that these "estated men now are like Jonah's gourd" and details the humble origins of the "creolians" largely lacking an education and flouting the rules of church and state. In particular, he cites their refusal to abide by the Deficiency Act which required slave owners to procure from England one white person for every 40 enslaved Africans, thereby hoping to expand their own estates and inhibit further English/Irish immigration. Lawes describes the government as being "anarchical, but nearest to any form of Aristocracy", further arguing: "Must the King's good subjects at home who are as capable to begin plantations, as their Fathers, and themselves were, be excluded from their Liberty of settling Plantations in this noble Island, for ever and the King and Nation at home be deprived of so much riches, to make a few upstart Gentlemen Princes?"

Albania (1997)

In 1997, Albania fell into a state of anarchy, mainly due to the heavy losses of money caused by the collapse of pyramid firms. As a result of the societal collapse, heavily armed criminals roamed freely with near total impunity. There were often 3–4 gangs per city, especially in the south, where the police did not have sufficient resources to deal with gang-related crime.

Somalia (1991–2006)

Map of Somalia showing the major self-declared states and areas of factional control in 2006

Following the outbreak of the civil war in Somalia and the ensuing collapse of the central government, residents reverted to local forms of conflict resolution, either secular, traditional or Islamic law, with a provision for appeal of all sentences. The legal structure in the country was divided along three lines, namely civil law, religious law and customary law (xeer).

While Somalia's formal judicial system was largely destroyed after the fall of the Siad Barre regime, it was later gradually rebuilt and administered under different regional governments such as the autonomous Puntland and Somaliland macro-regions. In the case of the Transitional National Government and its successor the Transitional Federal Government, new interim judicial structures were formed through various international conferences. Despite some significant political differences between them, all of these administrations shared similar legal structures, much of which were predicated on the judicial systems of previous Somali administrations. These similarities in civil law included a charter which affirms the primacy of Muslim shari'a or religious law, although in practice shari'a is applied mainly to matters such as marriage, divorce, inheritance and civil issues. The charter assured the independence of the judiciary which in turn was protected by a judicial committee; a three-tier judicial system including a supreme court, a court of appeals and courts of first instance (either divided between district and regional courts, or a single court per region); and the laws of the civilian government which were in effect prior to the military coup d'état that saw the Barre regime into power remain in forced until the laws are amended.

Economist Alex Tabarrok claimed that Somalia in its stateless period provided a "unique test of the theory of anarchy", in some aspects near of that espoused by anarcho-capitalists such as David D. Friedman and Murray Rothbard. Nonetheless, both anarchists and some anarcho-capitalists such as Walter Block argue that Somalia was not an anarchist society.

Anarchist movements

Russian Civil War (1917–1922)

Nestor Makhno, the leader of the anarchist Free Territory in Ukraine during the Russian Civil War in 1918

During the Russian Civil War which initially started as a confrontation between the Bolsheviks and monarchists, on the territory of today's Ukraine a new force emerged, namely the Anarchist Revolutionary Insurrectionary Army of Ukraine led by Nestor Makhno. The Ukrainian Anarchist during the Russian Civil War (also called the Black Army) organized the Free Territory, an anarchist society committed to resisting state authority, whether capitalist or communist. This project was cut short by the consolidation of Bolshevik power. Makhno was described by anarchist theorist Emma Goldman as "an extraordinary figure" leading a revolutionary peasants' movement.

During 1918, most of Ukraine was controlled by the forces of the Central Powers which were unpopular among the people. In March 1918, the young anarchist Makhno's forces and allied anarchist and guerrilla groups won victories against German, Austrian and Ukrainian nationalist (the army of Symon Petlura) forces and units of the White Army, capturing a lot of German and Austro-Hungarian arms. These victories over much larger enemy forces established Makhno's reputation as a military tactician and became known as Batko ("Father") to his admirers.

Makhno called the Bolsheviks dictators and opposed the "Cheka [secret police] ... and similar compulsory authoritative and disciplinary institutions" and called for "[f]reedom of speech, press, assembly, unions and the like". The Bolsheviks accused the Makhnovists of imposing a formal government over the area they controlled and also said that Makhnovists used forced conscription, committed summary executions and had two military and counter-intelligence forces, namely the Razvedka and the Kommissiya Protivmakhnovskikh Del (patterned after the Cheka and the GRU). However, later historians have dismissed these claims as fraudulent propaganda.

Spain (1936)

In 1936, the Spanish general Francisco Franco lead coup d'état aimed at overthrowing the Second Spanish Republic to establishing totalitarianism. At that time, the government of the Republic was in no position to stop the falangist coup. However, the first resistance to mobilize were anarchist trade unions which organized a general strike and created militias.

Given that power was in the hands of the trade unions, particularly the CNT, they began to establish anarchism in what was the Spanish Revolution of 1936. This was a social revolution as much as a political revolution. Throughout the war and shortly after, many Spanish working-class citizens lived in anarchist communities, many of which thrived during this time.

However, the government of the Spanish Republic and the Communist Party of Spain began to regain power through support from the Soviet Union. There was a divide between those that wanted to use the revolution as a force to undermine the Falangists by causing uprisings behind their lines and those that wanted to fight a traditional war using the government-controlled Popular Front. In the Soviet Union, Joseph Stalin and the Communist International (Comintern) which he led, was in favor of the popular front approach. Desperate to defeat the Falangists, who were getting support from Nazi Germany and Fascist Italy, the government of the Spanish Republic and the Communist Party of Spain decided to seize back control from the anarchist unions and crush most of the revolution in what became known as the May Days of 1937.

Eventually, the popular front approach would not work, as the Nationalists won the war and set up a military dictatorship led by Franco, ending the last of the remaining anarchist communes.

Lists of ungoverned communities

Ungoverned communities

The entrance of Freetown Christiania, a Danish neighborhood which claims autonomy from local government controls
 
On June 8, 2020, the police-free Capitol Hill Autonomous Zone was established in the Capitol Hill neighborhood of Seattle.

Anarchist communities

Anarchists have been involved in a wide variety of communities. While there are only a few instances of mass society anarchies that have come about from explicitly anarchist revolutions, there are also examples of intentional communities founded by anarchists.

Intentional communities
Mass societies

Nuclear power in space

From Wikipedia, the free encyclopedia
 
The KIWI A prime nuclear thermal rocket engine
 
Mars Curiosity rover powered by a RTG on Mars. White RTG with fins is visible at far side of rover.

Nuclear power in space is the use of nuclear power in outer space, typically either small fission systems or radioactive decay for electricity or heat. Another use is for scientific observation, as in a Mössbauer spectrometer. The most common type is a radioisotope thermoelectric generator, which has been used on many space probes and on crewed lunar missions. Small fission reactors for Earth observation satellites, such as the TOPAZ nuclear reactor, have also been flown. A radioisotope heater unit is powered by radioactive decay and can keep components from becoming too cold to function, potentially over a span of decades.

The United States tested the SNAP-10A nuclear reactor in space for 43 days in 1965, with the next test of a nuclear reactor power system intended for space use occurring on 13 September 2012 with the Demonstration Using Flattop Fission (DUFF) test of the Kilopower reactor.

After a ground-based test of the experimental 1965 Romashka reactor, which used uranium and direct thermoelectric conversion to electricity, the USSR sent about 40 nuclear-electric satellites into space, mostly powered by the BES-5 reactor. The more powerful TOPAZ-II reactor produced 10 kilowatts of electricity.

Examples of concepts that use nuclear power for space propulsion systems include the nuclear electric rocket (nuclear powered ion thruster(s)), the radioisotope rocket, and radioisotope electric propulsion (REP). One of the more explored concepts is the nuclear thermal rocket, which was ground tested in the NERVA program. Nuclear pulse propulsion was the subject of Project Orion.

Regulation and hazard prevention

After the ban of nuclear weapons in space by the Outer Space Treaty in 1967, nuclear power has been discussed at least since 1972 as a sensitive issue by states. Particularly its potential hazards to Earth's environment and thus also humans has prompted states to adopt in the U.N. General Assembly the Principles Relevant to the Use of Nuclear Power Sources in Outer Space (1992), particularly introducing safety principles for launches and to manage their traffic.

Benefits

Both the Viking 1 and Viking 2 landers used RTGs for power on the surface of Mars. (Viking launch vehicle pictured)

While solar power is much more commonly used, nuclear power can offer advantages in some areas. Solar cells, although efficient, can only supply energy to spacecraft in orbits where the solar flux is sufficiently high, such as low Earth orbit and interplanetary destinations close enough to the Sun. Unlike solar cells, nuclear power systems function independently of sunlight, which is necessary for deep space exploration. Nuclear-based systems can have less mass than solar cells of equivalent power, allowing more compact spacecraft that are easier to orient and direct in space. In the case of crewed spaceflight, nuclear power concepts that can power both life support and propulsion systems may reduce both cost and flight time.

Selected applications and/or technologies for space include:

Types

Name and model Used on (# of RTGs per user) Maximum output Radio-
isotope
Max fuel
used (kg)
Mass (kg) Power/mass (Electrical W/kg)
Electrical (W) Heat (W)
MMRTG MSL/Curiosity rover and Perseverance/Mars 2020 rover c. 110 c. 2000 238Pu c. 4 <45 2.4
GPHS-RTG Cassini (3), New Horizons (1), Galileo (2), Ulysses (1) 300 4400 238Pu 7.8 55.9–57.8 5.2–5.4
MHW-RTG LES-8/9, Voyager 1 (3), Voyager 2 (3) 160 2400 238Pu c. 4.5 37.7 4.2
SNAP-3B Transit-4A (1) 2.7 52.5 238Pu ? 2.1 1.3
SNAP-9A Transit 5BN1/2 (1) 25 525 238Pu c. 1 12.3 2.0
SNAP-19 Nimbus-3 (2), Pioneer 10 (4), Pioneer 11 (4) 40.3 525 238Pu c. 1 13.6 2.9
modified SNAP-19 Viking 1 (2), Viking 2 (2) 42.7 525 238Pu c. 1 15.2 2.8
SNAP-27 Apollo 12–17 ALSEP (1) 73 1,480 238Pu 3.8 20 3.65
(fission reactor) Buk (BES-5)** US-As (1) 3000 100,000 highly enriched 235U 30 1000 3.0
(fission reactor) SNAP-10A*** SNAP-10A (1) 600 30,000 highly enriched 235U
431 1.4
ASRG**** prototype design (not launched), Discovery Program c. 140 (2x70) c. 500 238Pu 1 34 4.1

Radioisotope systems

SNAP-27 on the Moon

For more than fifty years, radioisotope thermoelectric generators (RTGs) have been the United States’ main nuclear power source in space. RTGs offer many benefits; they are relatively safe and maintenance-free, are resilient under harsh conditions, and can operate for decades. RTGs are particularly desirable for use in parts of space where solar power is not a viable power source. Dozens of RTGs have been implemented to power 25 different US spacecraft, some of which have been operating for more than 20 years. Over 40 radioisotope thermoelectric generators have been used globally (principally US and USSR) on space missions.

The advanced Stirling radioisotope generator (ASRG, a model of Stirling radioisotope generator (SRG)) produces roughly four times the electric power of an RTG per unit of nuclear fuel, but flight-ready units based on Stirling technology are not expected until 2028. NASA plans to utilize two ASRGs to explore Titan in the distant future.

Cutaway diagram of the advanced Stirling radioisotope generator.

Radioisotope power generators include:

Radioisotope heater units (RHUs) are also used on spacecraft to warm scientific instruments to the proper temperature so they operate efficiently. A larger model of RHU called the General Purpose Heat Source (GPHS) is used to power RTGs and the ASRG.

Extremely slow-decaying radioisotopes have been proposed for use on interstellar probes with multi-decade lifetimes.

As of 2011, another direction for development was an RTG assisted by subcritical nuclear reactions.

Fission systems

Fission power systems may be utilized to power a spacecraft's heating or propulsion systems. In terms of heating requirements, when spacecraft require more than 100 kW for power, fission systems are much more cost effective than RTGs.

In 1965, the US launched a space reactor, the SNAP-10A, which had been developed by Atomics International, then a division of North American Aviation.

Over the past few decades, several fission reactors have been proposed, and the Soviet Union launched 31 BES-5 low power fission reactors in their RORSAT satellites utilizing thermoelectric converters between 1967 and 1988.

In the 1960s and 1970s, the Soviet Union developed TOPAZ reactors, which utilize thermionic converters instead, although the first test flight was not until 1987.

In 1983, NASA and other US government agencies began development of a next-generation space reactor, the SP-100, contracting with General Electric and others. In 1994, the SP-100 program was cancelled, largely for political reasons, with the idea of transitioning to the Russian TOPAZ-II reactor system. Although some TOPAZ-II prototypes were ground-tested, the system was never deployed for US space missions.

In 2008, NASA announced plans to utilize a small fission power system on the surface of the Moon and Mars, and began testing "key" technologies for it to come to fruition.

Proposed fission power system spacecraft and exploration systems have included SP-100, JIMO nuclear electric propulsion, and Fission Surface Power.

SAFE-30 small experimental reactor

A number of micro nuclear reactor types have been developed or are in development for space applications:

Nuclear thermal propulsion systems (NTR) are based on the heating power of a fission reactor, offering a more efficient propulsion system than one powered by chemical reactions. Current research focuses more on nuclear electric systems as the power source for providing thrust to propel spacecraft that are already in space.

Other space fission reactors for powering space vehicles include the SAFE-400 reactor and the HOMER-15. In 2020, Roscosmos (the Russian Federal Space Agency) plans to launch a spacecraft utilizing nuclear-powered propulsion systems (developed at the Keldysh Research Center), which includes a small gas-cooled fission reactor with 1 MWe.

In September 2020, NASA and the Department of Energy (DOE) issued a formal request for proposals for a lunar nuclear power system, in which several awards would be granted to preliminary designs completed by the end of 2021, while in a second phase, by early 2022, they would select one company to develop a 10-kilowatt fission power system to be placed on the moon in 2027.

Artists's Conception of Jupiter Icy Moons Orbiter mission for Prometheus, with the reactor on the right, providing power to ion engines and electronics.

Project Prometheus

In 2002, NASA announced an initiative towards developing nuclear systems, which later came to be known as Project Prometheus. A major part of the Prometheus Project was to develop the Stirling Radioisotope Generator and the Multi-Mission Thermoelectric Generator, both types of RTGs. The project also aimed to produce a safe and long-lasting space fission reactor system for a spacecraft's power and propulsion, replacing the long-used RTGs. Budget constraints resulted in the effective halting of the project, but Project Prometheus has had success in testing new systems. After its creation, scientists successfully tested a High Power Electric Propulsion (HiPEP) ion engine, which offered substantial advantages in fuel efficiency, thruster lifetime, and thruster efficiency over other power sources.

Visuals

A gallery of images of space nuclear power systems.

Operator (computer programming)

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