Spot Senior Space Science Booklet 2024-25 PDF

STUDENT BOOKLET SENIORS - 2024 - 25 1 Dear Student, SPOT Assessment is purely based on the science aptitude of the learner. The textual portion, the learner studies in the respective class need to be reaffirmed. You can do careful reading of any materials in science whi...

STUDENT BOOKLET SENIORS - 2024 - 25 1 Dear Student, SPOT Assessment is purely based on the science aptitude of the learner. The textual portion, the learner studies in the respective class need to be reaffirmed. You can do careful reading of any materials in science which can improve your knowledge horizons. This booklet will help you to identify the other topics that are broadly covered for this year’s SPOT PRELIMS & SPOT 100’S 2  INDEX Sr. No Contents Page No 1. BRANCHES OF SCIENCE 4 2. GREAT SCIENTISTS 19 3. INDIA IN SPACE 34 4. ARTIFICIAL SATELLITES 41 5. FACTS ABOUT ROCKETS 47 6. WORLD SPACE WEEK 54 7. OZONE LAYER 57 3  BRANCHES OF SCIENCE SCIENCE is a concerted Human effort to understand, or to understand better, the history of how the natural world works, with observable physical evidence as the basis of that understanding. It is done through observation of natural phenomena, and or through experimentation that tries to stimulate natural processes under controlled conditions. The Major Branches of Science Science is a systematic study of the nature and manners of an object and the natural universe that is established around measurement, experiment, observation and formulation of laws. There are four major branches of science; each branch is categorized in differenttype of subjects that covers different areas of studies such us chemistry, physics, mathematics, astronomy etc. The four major branches of science are Mathematics and logic, natural science, physical science and social science. Physical Science is classified into three: Physics - A natural science that involves the study of matter, motion, energy, force, objects, etc. related touniverse and its function Chemistry – The study and analysis of various elements, composition, structure, chemical process, etc. Astronomy – The study of objects beyond theatmosphere of the earth Earth Science is a branch of Physical science Classified into five: Ecology - The study of environment, relation oflliving organisms in the environment and ecosystem Oceanology –Otherwise known as Marine Science Geology – The study about various aspects of earth, an interesting branch that deals with digging the past Paleontology – Similar to Geology, which deals withthe study of various objects that existed in the prehistoric period 4 Life Science or Biological science Biology – Natural science and in-depth study of living organisms, from evolution to destruction. Botany – A known branch of science, studying about plant kingdom Zoology – The twin branch of botany, study of animal kingdom Human Biology– The study about human beings, nutrition,diseases, medicine, etc. Genetic Science – The study about genes, genetic facts,diseases of genes, etc. Medicine – The study, diagnosis, research, etc. of variousdiseases and treatments SOCIAL SCIENCE A branch of science that deals with the society and human behaviorin it, including anthropology, communication studies, criminology, economics, geography, history, political science, psychology, social studies, and sociology. Applications of some important branches of science and the scope of learning PHYSICS Physics is the study of energy and matter with respect to space and time. Physics is used heavily in engineering. For example, statics, a subfield of mechanics, is used in the building of bridges and other static structures. The understanding and use of acoustics results in sound control and construction of better concert halls; similarly, the use of optics creates better optical devices. An understanding of physics makes for more realistic flight simulators, video games, and movies, and is often critical in forensic investigations. With the standard consensus that the laws of physics are universal and do notchange withtime, physics can be used to study things that would ordinarily be mired in uncertainty. For example, in the study of the origin of the earth,one can reasonably model earth’s mass, temperature, and rate of rotation, as a function of time allowing one to extrapolate forward or backward in time and so predict future or prior events. It also allowsfor 5 simulations in engineering which drastically speeds up the development of new technologies. BOTANY The study of plants is vital because they underpin almost all animal life on Earth by generating a large proportion of the oxygen and foodthat provide humans and other organisms with aerobic respiration with the chemical energy they need to exist. Plants, algae and cyanobacteria are the major groups of organisms that carry out photosynthesis, a process that uses the energy of sunlight to convertwater and carbon dioxide into sugars that can be used both as a source of chemical energy and of organic molecules that are used inthe structural components of cells. As a by-product of photosynthesis, plants release oxygen into the atmosphere, a gas that is required bynearly all living things to carry out cellular respiration. In addition, they are influential in the global carbon and water cycles and plant roots bind and stabilize soil, preventing soil erosion. Plants are crucialto the future of human society as they provide food, oxygen,medicine, and products for people, as well as creating and preservingsoil. ZOOLOGY Study of Zoology is great importance to man. It has helped man to recognize the living things and to adapt himself according to the environment. The students of Zoology can learn about animals and Zoological principles which may help them for proper maintenance oflife. Zoologist acquires the power to evaluate the nature which is notpossible by the other means. The scope of applied Zoology is innumerable. It provides the knowledge of medicine, dentistry, Veterinary medicine, medical technology, nursing, Museum Work, zoological teaching, zoological research, agriculture, environmental science, and conservation. Genetics is another branch of zoology. Itsknowledge has brought revolution in plant and animal breeding. There is every possibility that our non-renewable natural resources will be exhausted in near future. The conservation of these natural resources may be possible through zoological knowledge. ASTRONOMY Astronomy is one of the few sciences where amateurs can still play an active role, especially in the discovery and observation of transient 6 phenomena. Amateur astronomers have made and contributed to many important astronomical discoveries, such as finding new comets. ECOLOGY The scope of ecology contains a wide array of interacting levels of organization spanning micro-level (e.g., cells) to a planetary scale (e.g., biosphere) phenomena. Ecosystems, for example, contain abiotic resources and interacting life forms (i.e., individual organisms that aggregate into populations which aggregate into distinct ecological communities). Ecosystems are dynamic, they do not always follow a linear successional path, but they are always changing, sometimes rapidly and sometimes so slowly that it can takethousands of years for ecological processes to bring about certain successional stages of a forest. An ecosystem’s area can vary greatly,from tiny to vast. A single tree is of little consequence to the classification of a forest ecosystem, but critically relevant to organisms living in and on it. GEOLOGY Geology (in Greek, Geo means Earth, Logos means Science) is a branch of science dealing with the study of the Earth. It is also knownas earth science. Geology provides a systematic knowledge of construction materials, their structure and properties. The knowledge of Erosion, Transportation and Deposition (ETD) by surface water helps in soil conservation, river control, coastal and harbor works. CHEMISTRY Chemistry is more specialized, being concerned by the composition, behavior (or reaction), structure, and properties of matter, as well asthe changes it undergoes during chemical reactions. It is a physical Science which studies various substances, atoms,molecules and matter Biochemistry, the study of substances found in biological organisms; physical chemistry, the study of chemical processes using physical concepts such as thermodynamics and quantum mechanics; and analytical chemistry, the analysis of material samples to gain an understanding of their chemical composition and structure. Many more specialized disciplines have emerged in recent years, 7 e.g. neurochemistry the chemical study of the nervous system. LIFE SCIENCE Life science comprises the branches of science that involve the scientific study of living organisms, like plants, animals, and human beings. However, the study of behavior of organisms, such aspracticed in ethology and psychology, is only included in as much asit involves in a clearly biological aspect. While biology remains the centerpiece of life science, technological advances in molecularbiology and biotechnology have led to a burgeoning of specializations and new, often interdisciplinary, fields. HUMAN BIOLOGY Human biology is an interdisciplinary academic field of biology, biological anthropology, nutrition and medicine which focuses on humans; it is closely related to primate biology, and a number of other fields. Some branches of biology include microbiology, anatomy, neurology and neuroscience, immunology, genetics, physiology, pathology, biophysics, and ophthalmology. 8  BRANCHES OF SCIENCE AND ITS DEFINITION Aerodynamics : the study of the motion of gas on objects and the forces created Anatomy : the study of the structure and organization of living things Anthropology : the study of human cultures both past and present Archaeology : the study of the material remains of cultures Astronomy : the study of celestial objects in the universe Astrophysics : the study of the physics of the universe Bacteriology: the study of bacteria in relation to disease Biochemistry : the study of the organic chemistry of compounds and processes occurring in organisms Biophysics : the application of theories and methods of the physical sciences to questions of biology Biology : the science that studies living organisms Botany : the scientific study of plant life Chemical Engineering: the application of science, mathematics, and economics to the process of converting raw materials or chemicals into more useful or valuable forms Chemistry : the science of matter and its interactions with energy and itself Climatology : the study of climates and 9  investigations of its phenomena and causes. Ecology : the study of how organisms interact with each other and to their environment Electronics : science and technology of electronic phenomena Entomology : the study of insects Environmental Science : the science of the interactions between the physical, chemical, and biological components of the environment Genetics : the science of genes, heredity, and the variation of organisms Geology : the science of the Earth, its structure, and history Marine Biology : the study of animal and plant life within Saltwater ecosystems Medicine : the science concerned with maintaining health and restoring it by treating disease Meteorology : study of the atmosphere that focuses on weather processes and forecasting Microbiology : the study of microorganisms, including viruses, prokaryotes and simple eukaryotes Mineralogy : the study of the chemistry, crystal structure, and physical (including optical) properties of minerals Molecular Biology : the study of biology at molecular level Nuclear Physics : the branch of physics which deals with the structure of atomic nucleus and the nuclear radiation. 10 Neurology : the branch of medicine dealing with the nervous system and its disorders Oceanography : study of the earth’s oceans, their Inter linked ecosystems and chemical and physical processes Ornithology : the study of birds Paleontology : the study of life-forms existing in former geological time periods Physics : the study of the behavior and properties of matter Physiology : the study of the mechanical, physical, and biochemical functions of living organisms Radiology : the branch of medicine dealing with the applications of radiant energy in imaging technology, which includes x- rays and radioisotopes Seismology : A branch of geophysics which deals with the study of earthquakes and the movement of waves within the Earth Taxonomy : the science of classification of animals and plants Thermodynamics : the physics of energy, heat, work, entropy and the spontaneity of processes Zoology : the study of animals 11  GREAT INDIAN SCIENTISTS Sir. Jagadish Chandra Bose (1858-1937) Jagadish Chandra Bose was born on 30 November 1858, in Myemsingh, Faridpur, a part of the Dhaka District now in Bangladesh.He attended the village school till he was 11. He then moved to Kolkata where he enrolled in St. Xavier’s. He was very much interested in Biology. However, Father Lafont, a famous Professor of Physics, inspired Bose, a great interest in Physics. Having obtained his B.A. in physical sciences, twenty-two-year-old Bose left forLondon, to obtain a medical degree. However, he kept falling ill andhad to discontinue his plans to be a doctor. He then obtained his B.A. degree from Christ College, Cambridge. He returned to India in 1885and joined Presidency College, Kolkata as an Assistant Professor of Physics, were he remained till 1915. During this period, Bose also started doing original scientific work inthe area of microwaves, carrying out experiments involving refraction, diffraction and polarization. He developed the use of galena crystals for making receivers, both for short wavelength radiowaves and for white and ultraviolet light. In 1895, two years before Marconi’s demonstration, Bose demonstrated wirelesscommunication using radio waves, to ring a bell remotely and to explode some gunpowder. Many of the microwave components familiar today - waveguides, horn antennas, polarizers, dielectric lenses and prisms, and even semiconductor detectors of electromagnetic radiation - were invented and used by Bose in the last decade of the nineteenth century. He also suggested the existence of electromagnetic radiation from the Sun, which was confirmed in 1944. Bose then turned his attention to response phenomena in plants. He showed that not only animal tissues, but vegetable tissues also produce similar electric response under different kinds of stimuli likemechanical, thermal, electrical and chemical. Bose was knighted in 1917 and soon thereafter elected as Fellow of the Royal Society, London, (both as physicist and biologist!). 12 Bose had worked all along without the right kind of scientific instruments and laboratory. For a long time, he had been thinking ofbuilding a laboratory. The result was the establishment of the Research Institute in Kolkata. It continues to be a famouscenter of research in basic sciences. Srinivasa Ramanujan (1887-1920) Ramanujan was born in Erode, a small village in Tamil Nadu on 22 December 1887. When he was a year old his family moved to the town of Kumbakonam, where his father worked as a clerk in a clothmerchant’s shop. When he was nearly five years old, Ramanujan enrolled in the primary school. In 1898 he joined theTown High School in Kumbakonam. At the Town High School, Ramanujan did well in all subjects and proved himself an able all round scholar. It was here that he came across the book Synopsis of Elementary Results in Pure Mathematics by G. S. Carr. Influenced by the book, he began working on mathematics on his own, summing geometric and arithmetic series. He was given a scholarship to the Government College in Kumbakonam. However, his scholarship was not renewed because Ramanujan neglected all subjects other than mathematics. In 1905 he appeared for the First Arts examination which would have allowedhim to be admitted to the University of Madras. Again, he failed in allsubjects other than mathematics, a performance he repeated in 1906and 1907 too. In the following years he worked on mathematics, withonly Carr’s book as a guide, noting his results in what would becomethe famous Notebooks. He continued to pursue mathematics and in 1913 he wrote to G. H. Hardy in Cambridge, enclosing a long list of his own theorems. Hardy immediately recognized Ramanujan’s mathematical ability. On the basis of Hardy’s letters, Ramanujan was given a scholarship by the University of Madras in 1913. In 1914, Hardy arranged for himto go to Trinity College, Cambridge. Ramanujan’s work with Hardy produced important results right from the beginning. In 1916 Ramanujan graduated from Cambridge with a Bachelor of Science byResearch. In 1918, he was 13 elected a Fellow of the Cambridge Philosophical Society, a Fellow of the Royal Society of London, and aFellow of Trinity College, Cambridge, all in the same year! However,from 1917 onwards he was seriously ill and mostly bedridden. In 1919 he returned to India, in very poor health. Ramanujan made outstanding contributions to analytical number theory, elliptic functions, continued fractions, and infinite series. His published and unpublished works have kept some of the best mathematical brains in the world busy to this day. Sir C. V. Raman (1888-1970) Chandrasekhara Venkata Raman was born at Tiruchirappalli in TamilNadu on 7th November 1888. His father was a lecturer in mathematicsand physics so from the very beginning he was immersed in an academic atmosphere. Raman’s academic brilliance was established at a very young age. He finished his secondary school education at the tender age of thirteen and entered the Mrs. A.V.N. College at Vishakhapatnam, Andhra Pradesh. Two years later he moved to the prestigious Presidency College in Chennai. When he was fifteen, he topped his class to receive his B.A. degree with honours in Physics and English. Raman continued his studies at the Presidency College and when he was barely eighteen, graduatedat the top of his class and received his M.A. degree with honours. In 1917, C V Raman gave up his government job to become the Sir Taraknath Palit Professor of Physics at the Science College of University of Calcutta (1917-33). He made enormous contributions toresearch in the areas of vibration, sound, musical instruments, ultrasonics, diffraction, photoelectricity, colloidal particles, X-ray diffraction, magnetron, dielectrics, etc. In particular, his work on thescattering of light during this period brought him world-wide recognition. In 1924 he was elected a Fellow of the Royal Society of London anda year 14 later was honored with the prestigious Hughes medal from theRoyal Society. Four years later, at the joint meeting of the South Indian Science Association and the Science Club of Central College, Bangalore, he announced his discovery of what is now known as theRaman Effect. He was knighted in 1929, and in 1930, became the first Asian scientist to be awarded the Nobel Prize for Physics for his discoveries relating to the scattering of light (the Raman Effect). In 1934, he became the Director of the newly established IndianInstitute of Science at Bangalore, where he remained till his retirement. After retirement, he established the Raman Research Institute at Bangalore, where he served as the Director. The Government of India conferred upon him its highest award, the Bharat Ratna in 1954. Homi Jehangir Bhabha (1909-1966) Homi Bhabha was born on 30 October 1909 in Mumbai. Son of a barrister, he grew up in a privileged environment. In Mumbai he attended the Cathedral & John Connon School and then Elphinstone College, followed by the Royal Institute of Science. After passing the Senior Cambridge Examination at the age of sixteen, he joined the Gonvile and Caius College in Cambridge with an intention to pursue mechanical engineering. His mathematics tutor was Paul Dirac, and Bhabha became fascinated with mathematics and theoretical physics.He earned his engineering degree in 1930 and Ph.D. in 1934. In 1937, together with W. Heitler, a German physicist, Bhabha solvedthe riddle about cosmic rays. Cosmic rays are fast moving, extremelysmall particles coming from outer space. When these particles enter the earth’s atmosphere, they collide with the atoms of air and createa shower of electrons. Bhabha’s discovery of the presence of nuclear particles (which he called mesons) in these showers was used to validate Einstein’s theory of relativity making him world famous. In 1940, C.V. Raman, then head of the Physics Department, Indian Institute of Science, Bangalore, persuaded Bhabha to join the institute as a Reader in Physics and Bhabha decided to stay back in India. In 1941, Homi Bhabha was elected Fellow of the Royal Society,London, in recognition of his contributions to the field of cosmic rays,elementary 15 particles and quantum mechanics. Bhabha soon realizedthe need for an institute fully devoted to fundamental research and wrote to J.R.D. Tata for funding. This resulted in the establishment of the Tata Institute of Fundamental Research (TIFR) in Mumbai in 1945, with Bhabha as the Director, a position he held until his death. In 1948, Homi Bhabhawas appointed the Chairman of the International Atomic Energy Commission. Under his guidance, nuclear reactors like the Apsara, Cirus and Zerlina were built. He gained international recognition for his excellent work and served as the President of the first United Nations Conference on the Peaceful Uses of Atomic Energy, which was held in Geneva in 1955. He was the President of the InternationalUnion of Pure and Applied Physics from 1960 to 1963. He is the recipient of the Adam’s Award, Padma Bhushan, an Honorary Fellowof the American Academy of Arts and Sciences and Foreign Associateof the National Academy of Sciences in the United States. Vikram Sarabhai (1919-1971) Vikram Sarabhai was born on 12 August 1919 at Ahmedabad. He hadhis early education in a private school, ‘Retreat’ run by his parents on Montessori lines. This atmosphere injected into the young boy the seeds of scientific curiosity, ingenuity and creativity. With a natural inclination towards physics and mathematics, Vikram Sarabhai did notget into his family business. After school and college in Gujarat, he went to England and obtained his tripos at St. John’s College in 1939. He returned to India for a while and worked alongside Sir C.V. Ramanin the field of cosmic rays, at the Indian Institute of Science in Bangalore, after which he returned to Cambridge, England for furtherresearch in the area and completed his Ph.D. in 1947. He established the Physical Research Laboratory in Ahmedabad in 1948, in a few rooms at the M.G. Science Institute with Professor K.K. Ramanathan as Director. In April 1954, PRL moved into a new 16 building and Dr. Sarabhai made it the cradle of the Indian Space Programme. At the young age of 28, he was asked to organise and create the ATIRA, the Ahmedabad Textile Industry’s Research Association and was its Honorary Director during 1949-56. He also helped build and direct the Indian Institute of Management, Ahmedabad from 1962-1965. Sarabhai pioneered India’s space age by expanding the Indian Space Research Organization. India’s first satellite Aryabhata launched in 1975, was one of the many projects planned by him. Like Bhabha, Sarabhai wanted the practical application of science to reach the common man. Thus, he saw a golden opportunity to harness space science to the development of the country in the fields of communication, meteorology, remote sensing and education. The Satellite Instructional Television Experiment (SITE) launched in 1975- 76, brought education to five million people in 2,400 Indian villages. In 1965, he established the Community Science Centre in Ahmedabad with a view to popularise science among children. His deep cultural interests led him, along with his wife Mrinalini Sarabhai,to establish Darpana Academy, an institution devoted to performingarts and propagation of ancient culture of India. He was the recipientof the Bhatnagar Memorial Award for Physics in 1962, the Padma Bhushan in 1966, and was posthumously awarded the Padma Vibhushan. He was the Chairman of the Atomic Energy Commission in 1966, Vice- President and Chairman of the UN Conference on peaceful uses of outer space in 1968, and Presidentof the 14th General Conference of the International Atomic EnergyAgency. The International Astronomical Union named a crater in themoon (in the Sea of Serenity) after him, in honour of his contributionsto science. 17 DR. A.P.J. ABDUL KALAM (1931 - 2015) Dr. A.P.J.Abdul Kalam, the eleventh President of India was born on15 October, 1931, in the island town of Rameswaram, in Tamil Nadu.He was awarded the Bharat Ratna, India’s highest civilian honour in 1997 for his contributions in the field of science and engineering. Dr. APJ Kalam served in Indian Space Research Organisation (ISRO) from 1963 to 1982. At Vikram Sarabhai Space Centre, he developed the Satellite Launch Vehicle (SLV 3), which put the satellite Rohini into orbit. In 1982, as Director in Defense Research Development Organisation (DRDO), he was given the responsibility of Integrated Guided Missile Development Programme (IGMDP). He developed fiveprojects for defense services - Prithvi, Trishul, Akash, Nag and Agni.He led India into an era of self-dependence. Agni, which is a surface- to-surface missile, is a unique achievement. Its successful launch made India a member of the club of highly developed countries. 18  GREAT SCIENTISTS GALIELO GALIELI Galileo Galilei was a groundbreaking Italian astronomer, physicist, mathematician, philosopher and inventor. He opened the eyes of the world to new way of thinking abouthow the solar system work. For many years, scientists had believed that the solar system revolved around the Earth, and that the earth was the center of the Universe. Galileo was the first scientist to prove that this wasn’t correct. He stated that in fact, the solar system revolved around the Sun. He also invented and improved telescope and so that he could gaze far into space. Hewas the first to see Jupiter’s moons, and the first to realise that our Moon was covered with craters. Besides Scopes, he also invented thecompass and the thermometer. Galileo has played a major role in the scientific revolution of the 17th Century. BLAISE PASCAL Blaise pascal was a 17th century French philosopher and scientist who made important contributions to math, science, and philosophy. While he was still a teenager, Pascal became oneof only two people who had developed and constructed a working mechanical calculator. As a mathematician, Pascal developed two separate fields of math-projective geometry, and probability theory. This Probability theorywas born out Pascal’s study of gambling problems and had an important development of the impact on the modern-day economics. In projective geometry, he developed that became known as Pascal’s triangles, in which the sums of successive numbers built on themselves to form the numbers built on themselves to form the numerical row beneath. Pascal ‘s scientific theories were important to understanding the properties and volume of solids using cycloids. pascal was also an expert in various languages, and a well – versed religious philosopher 19 JOHANNES KEPLER Johannes Kepler was a leading astronomer ofthe scientific Revolution. The Scientific Revolution is the term used to describe the emergence of modern science that took placethroughout the 16th and 17th centuries. Before the scientific Revolution, astronomy was closely tied to astrology, which is the belief that the movement of the stars and planets can be interpreted to predict the future. As the scientific Revolution progressed, astrology increasingly came to be replaced by astronomy as a modern, legitimate science.Johannes Kepler is best known for his discovery that the orbits in which the Earth and the other planets of the solar system travel around the sun are elliptical or oval in shape. He was also the first to explain correctly how human beings are ableto see and demonstrated what happens to light when it enters a telescope. In addition, he designed an instrument that serves as the basis of the modern refractive telescope. Since he was such a prominent figure in the field of astronomy, a lot of spots on distant planets havebeen named after him such as” Kepler’s Crater on Mars” and ‘The Kepler Crater’ on the Moon. ROBERT BOYLE Robert Boyle was the famous Anglo-Irish scientist who transformed chemistry in the 17thcentury, when chemistry was confined to alchemy and mysticism. Alchemy was the study of how to change the basic substances such as metals into other more valuable substance. Boyle made chemistry a science based on measurement. He defined elements, compounds and mixtures and he coined the new term ‘Chemical analysis’ a field in which 20 he made several contribution. Robert Boyle is most famous for Boyle’s Law. It was thefirst of the gas law linking the pressure of a gas to its volume. He established that electrical forces are transmitted through a vacuum, but not sound. Boyle also stated that the movement of particles is responsible for heat. He was the first person to write specific experimental guidancefor other scientists, telling them the importance of achieving reliableresults. He was indeed a ‘mighty chemist’. Robert Boyle is regarded as the first modern chemist and is referredto as one of the founders of modern chemistry. SIR ISSAC NEWTON Sir Issac Newton, an Englishman who lived in the 17th century, is a scientific legend. He came up with numerous theories and contributed ideas to many different fields includingphysics, mathematics, and philosophy. In 1687, Newton published his book philosophiae naturalis principia mathematica. In it, he describes universal gravitation, and the three laws of motion. It is widely regarded to be one of the mostimportant books in the history of science. It is well known that his work on formulating a theory of gravitation was inspired by watchingan apple falling from a tree. During his lifetime, Newton developed a new type of mathematics called calculus, and made breakthroughs in the area of optics such as the reflecting telescope. He also discovered that white light is made upof wide range of different colors. Newton was a deep thinker with an insatiable curiosity to know everything about everything he saw. His contributions are so numerous, that he changed forever the way in which we look at the world. 21 EDMOND HALLEY Edmond Halley was an English Scientist who became very interested in a comet that he saw in 1682. After being told that similar comet had appeared in 1531 and 1607, he suspectedthat it was the same comet that he had seen.By using the laws of gravity discovered by hisfriend Sir Issac Newton, Halley realized that he could predict when it would return. Halleyworked out that the comet would appear in our skies every 75 to 76 years. He was correct in his prediction, but sadly when the comet didreappear, he was no more, and he could not witness the confirmationhehad waited for so eagerly. In his honors , the comet was named after him. Though he is remembered foremost as an astronomer, Halley also made significant discoveries in the fields of geography, mathematics, meteorology, and Physics. Halley was very close to Newton. HENRY CAVENDISH The English scientist Henry Cavendish was an experimental chemist and physicist par excellence. Cavendish showed that hydrogen is much less dense than air. In 1785, hepublished a paper showing the Earth’s atmosphere consists of four parts nitrogen to one-part oxygen. In addition, to his achievements in chemistry, Cavendish experiment. He was the first tomeasure force of gravity between masses in a laboratory, and to produce accurate value for Earth’s density. Henry Cavendish also experimented with electricity, but much of his work on the subject was only published after his death. He was renowned for the great accuracy and precision of his scientific research. 22 WILLIAM HERSCHEL Willam Herschel was German – born British scientist who became one of the most important astronomersof the 18th century. He built his own telescopes. From the garden of his house, Willam Herschelnoted, every star in the heavenly space through a telescope that he had constructed himself. He also manufactured over 400 telescope s that were in greatdemand worldwide. His study of the heavenly bodies led him to the discovery of a planet that would eventually be called Uranus. Willam Herschel would also discover Titania and Oberon, which werethe moons of Uranus as well as Enceladus and Mimas, the moons Saturn. Herschel maintained that the solar system is moving through space and found out the direction of that movements. He also suggested that the milky way was in the shape of disc. Herschel is considered to be the founder of modern stellar astronomy. Willam Herschel, the great scientist was a gifted musician too. He played the oboe, violin, harpsichord, and organ. JEAN LAMARCK Jean Lamarck was one of the pioneers in the field of biology. In fact, the very name ‘Biology’was coined by this French naturalist. He is best remembered for his theory of evolution. According to this theory, the characteristics an organism develops during itslifetime in response to its environment are inherited by or passed on to its offspring. Lamarck was the first to use the term invertebrate to describe animals without backbones. He began collecting fossils and studying all sorts of simple species. As a result of these studies, he was able to revise the classificationof lower animals that had been unfinished by the Swedish biologistLinnaeus. Lamarck’s study of invertebrates also led to the publication of his major work ’The Natural History of Invertebrate Animals’ in 1815-22. 23 JOHN DALTON John Dalton, a British Scientist, is probably best known for his groundbreaking research and contribution to two completely different fields- atomic theory in chemistry. Theresearch had a great impact on atomic theory. He created a listing of atomic weight for six different elements – hydrogen, oxygen, nitrogen, carbon, sulfur, and phosphorous. Dalton’s interpretation of atomic theory maintained that atoms are combined in chemical reactions, but also that they can be separated and rearranged. Without doubt, it was John Dalton’s atomic theory that laid the foundations of modern chemistry. ANDREW MARIE AMPERE Andrew Marie Ampere was a French Physicist and mathematician, who made the revolutionary discovery that a wire carrying electric current can attract or repelanother wire next to it , which also carries electric current. The attraction with a magnet is necessary for the effect to be seen. Ampere went on to formulate Ampere’s Law of electromagnetism and produced the best definition of electric current of his time. He also proposed the existence of a particle we now reorganize as the electron, discovered the chemical element fluorine, and grouped elements by their properties. In recognition of Ampere’s contribution to modern electrical science, the ‘ampere’ was established as a standard unit of electrical measurement ,in 1881,forty-five years after his death. 24 MICHAEL FARADAY Michael faraday was a 19th century British chemistand Physicist. He is often called the father of electricity with good reason His work on electrochemistry and electromagnetism laid the foundation for many areas of science. It was in 1831 that Faraday discovered electromagnetic induction, the principle behind the electric transformer and generator. This discovery was crucial in allowing electricity to be transformed froma curiosity, into a powerful new technology. He was partly responsible for coining many familiar words including ‘electrode’, ‘cathode’ and ‘ion’. Faraday laid the basis of the electromagnetic field concept in physics, discovered the laws of electrolysis, and invented electromagnetic rotary device that were vital in the creation of electric motors. Faraday has thus played a key role in the development of electricity for use in modern technology CHARLES DARWIN Charles Darwin was an English naturalist who is best known for his ideas on evolution.In 1831, Darwin sailed on the HMS Beagle ,a naval survey ship. Darwin’s job was to collect plant and animal specimens from thecountries the ship visited. The voyage took five years. For Charles Darwin, the most important part of the journey was the timeto spent in the Galapagos islands which are the home to plants and animals that can’t be found anywhere else in the world. On his return to England, Darwin started to piece together his theory of natural selection which explained how populations evolved. In 1859, Charles Darwin published his book ‘On The Orgin Of Spices’. According to this theory all species of life have evolved over time from common ancestors. Charles Darwin changed the way humans viewed themselves. 25 JAMES PRESCOT JOULE FRS James Prescott Joule FRS (24 December 1818 – 11 October 1889) was an English physicist and brewer,born in Salford, Lancashire. Joule studied the natureof heat and discovered its relationship to mechanicalwork (see energy). This led to the law of conservation ofenergy, which led to the development of the first law of thermodynamics. The SI derived unit of energy, the joule, is named after James Joule. He worked with Lord Kelvin to develop the absolute scale of temperaturethe Kelvin. Joule also made observations of magnetostriction, and he found the relationship between the current through a resistor and the heat dissipated, which is now called Joule’s first law. In his early years, Joule proved that heat produced in a small electromagnet built by him was from electrical energy, which was in turn, generated by mechanical energy which powered the dynamo. The principle of conservation of energy became the first law of thermodynamics, a field of physics that Joule is referred to as the chief founder. Joule was the first person to calculate the speed of a molecule of gas, about 457 meters a second for oxygen at average temperatures which laid the foundations for the kinetic theory of gases in the future. Joule recognized the need for standard units of electricity. In fact, the units of energy is named ‘Joule’ in recognition of his contribution. GREGOR JOHANN MENDEL Gregor Johann Mendel was a German-speaking Moravian-Silesian scientist and Augustinian friar andabbot of St. Thomas’ Abbey in Brno who gained posthumous fame as the founder of the modern science of genetics. Though farmers had known for centuries that crossbreeding of animals and plants could favor certain desirable traits, Mendel’s pea plant experiments conducted between 1856 and 1863 established many of the rules of heredity, now 26 referred to as the laws of Mendelian inheritance. Mendel worked with seven characteristics of pea plants: plant height, pod shape and color, seed shape and color, and flower position and color. With seed color, he showed that when a yellow pea and a green pea werebred together their offspring plant was always yellow. However, in the next generation of plants, the green peas reappeared at a ratio of 1:3. Toexplain this phenomenon, Mendel coined the terms “recessive” and “dominant” in reference to certain traits. (In the preceding example, green peas are recessive and yellow peas are dominant.) He published hiswork in 1866, demonstrating the actions of invisible “factors”—now called genes— in providing for visible traits in predictable ways. The profound significance of Mendel’s work was not recognized until the turn of the20thcentury (more than three decades later) with the independent rediscoveryof these laws. Erich von Tschermak, Hugo de Vries, Carl Correns, and William Jasper Spillman independently verified several of Mendel’s experimental findings, ushering in the modern age of genetics DIMITRI MENDELEEV Dmitri Mendeleev was a Russian chemist and inventor who is best known for his discovery of the periodic law, which he introduced in 1869 and for his formulation of the periodic table of elements.As a professor, Mendeleev taught first at the St. Petersburg Technological institute and then at the University of St. Petersburg Realizing he was in need of a quality textbook to cover the subject of inorganic chemistry, he put together one of his own, ‘The principles of chemistry’. It was during this time that Mendeleev made the discoverythat led to his most famous achievement. He noticed certain recurringpatterns between different groups of elements and using existing knowledge of the elements chemical and physical properties, he was able to make further connections. He systematically arranged the known elements by atomic weight in a grid-like diagram. His diagram known as the periodic table of elements is still used today. He wrote a book on the spectroscope. 27  THOMAS EDISON Thomas Edison’s story is truly an inspiring one. Hestruggled at school but loved reading andconducting experiments. The American inventor began sending and receiving messages via Morse code- electronically conveyed alphabet using different clicks for each letter at the age of 15. Later, he invented a version of the telegraph that could send four messages at once In 1877, Edison invented the phonograph. The phonograph was a machine that recorded and played back sounds. He perfected the phonograph by recording ‘Mary had a Little lamb’ on a piece of foil In 1878 Edison invented the light bulb, as well as the power grid system which could generate electricity, and deliver it to homes through a network of wires. Edison registered 1093 patents in the US as he continues to invent products. He made significant contributions to storage batteries and motion pictures. His inventions changed the world forever, and Edison remains a colossus in the field of science to day. ALEXANDER GRAHAM BELL Alexander Graham Bell was an influential scientist, engineer, and inventor who is considered to be the inventor of the first practical telephone. Bell’s mother and wife were both deaf, and this motivated his research on hearing and speech. Bell experimented with sound, working with devices such as ‘harmonic telegraph’, that is used to send multiple messages over a single wire. While trying to discover the secret to transmitting multiple messages on a single wire. Bell heard the sound of plucked string alongsome of the electrical wire. This was caused because one of Bell’s assistants. Thomas A Watson was trying to reactivate a transmitter. It made Bell believe he could send the sound of a human voice 28 over the wire. After receiving a patent on March 7th , 1876, for transmitting sound alonga single wire, he successfully transmitted human speech on March 10. Bells’ first words with the working telephone were spoken to his assistant Watson. They were “Mr. Watson come here I want to see you”. Bell also had a strong interest in other scientific fields, conducting medical research, searching for alternative fuel sources, developing hydrofoil watercraft and much more. HENRI BECQEREL Henri Becquerel was a French physicist who discovered radio activity through his investigationsof uranium and other substances. Becquerel had become a highly respected physicist by 1896. After the discovery of the X- ray in 1895, Becquerel began to investigate whether there was a fundamental connection between thisform of invisible radiation and His expertise with phosphorescent materials, his familiarity with uranium components, and his general skill in laboratory techniques, including photography, all played a key role in his discovery of radioactivity. Becquerel experimented by placing phosphorescent crystals on a sealed photographic plate that had been wrapped in opaque paper, and neverexposed to direct light. After the plate was developed, images were visible on it. He passed the results on to Madame Curie, who named this phenomenon radioactivity. In 1903, Becquerel shared the Nobel Prize for Physics with the chemists Pierre and Marie Curie. 29  MAX PLANCK Max Planck was a German theoretical physicist, who made significantcontributions. He changed our understanding of physics when he discovered that hot object do not radiate a smooth, continuous range of energies as was earlier believed. Instead, he found that the energies radiated by hot objects have distinct values. His discovery was the beginning of the Quantum theory - an entirely new type of physics that revolutionized our understanding of atomic and subatomic processes. A quantum is the smallest possible amount of energy. Planck’s constant a fixed number is used to calculate the energy of quanta. The theory has been developed to explain the behavior of particles and the energy they emit. Planck was awarded the Nobel Prize in 1918. JJ THOMPSON JJ Thomson, an English physicist, took science to new heights with his 1897 discovery of the electron, the subatomic particle. When Thomson began his research career, it was thought that atoms were the smallest particles. Nobody had a clear picture of how atoms might look. It was already known that atoms were associated in some way with electric charges. In 1897 aged 40, Thomson carried out a now famous experiment with a cathode ray tube. His experiment proved the existence of a new fundamental particle that was much smaller than the atom. It was named the electron. In discovering the electron, Thomson also moved towards theinvention of an immensely important tool for chemical analysis the mass spectrometer. 30  Then in 1912 Thomson discovered that stable elements could exists as isotopes are different forms of the same element that exist with different atomic masses. J J Thomson was awarded the Nobel prize for Physics in 1906. MARIE CURIE She was the first woman to win the Nobel prize twice. Marie’s research was the field of radioactivity. With the help of her husband Pierre Curie, she made numerous scientific discoveries; including one showing that radiation did indeed comefrom the atom itself. The 1903 Nobel Prize in Physics was awarded to Marie and Pierre aswell as Henri Becquerel for their work in radiation. In 1911, Marie Curie was awarded another Nobel Prize, this time in Chemistry, for her discovery of radium and polonium, and subsequent research. Marie curie became internationally famous and scientists came from around the world to study radioactivity with her. The Curie institute in Paris founded by Marie in 1921 is still a major cancer research facility to this day. ALBERT EINSTEIN Albert Einstein was an intellectual giant whose scientific achievements influenced the philosophy of science forever. Born in Germany, he made some contributionsto the field of theoretical physics, and 1921, won a Nobel Prize for his work in this field. In 1905 he began publishing the componentsof his Special Theory of Relativity, in which he demonstrated that time was relative to the speed at which the observer was travelling. The essence of Einstein’s Special Theory of relativity was that if matter 31 is converted into energy, then energy released can be shownin the simple formula E= MC2 where C represents the velocity of light,Ethe energy and M the mass. In 1915 Einstein rocked the world with his General Theory ofRelativity. It explained a lot of how time and distance may change due to the ‘relative’ or different speed of the objects and the observer. Einstein became famous overnight, and all of a sudden, hewas showered with honors from all over the world! Einstein’s vision and his theories of relativity and quantum physics are with our doubt, the hallmarks of a scientific genius. ALEXANDERF FLEMING Alexander Fleming, a Scottish biologist, pharmacologist, and botanist, made history with the discovery of penicillin, the world’s first antibiotic substance in 1928. Fleming was studying deadly bacteria when hemade his awesome discovery, quite by accident. He had unintentionally left open thecover of bacteria culture plate with which he was working when he went away on a holiday. When he returned, he noticed that a mould had formed on the exposed culture. What interested him wasthe fact that in the area surrounding the mould, the bacteria had disappeared.He kept a strain of the mold alive and began testing it on laboratory animals. With further experimentation, Fleming established that this mould, that he named penicillin, could destroy many types of bacteria, such as the ones responsible for scarlet fever,meningitis, and diphtheria. Fleming published his research on penicillin, with two other scientists. However, Florey and Ernst Boris Chain discovered how to isolate the penicillin and increase its potential. These findings were used to mass-produce penicillinin order to treat wounded soldiers during World War II, thus saving millionsoflives. 32 STEPHEN HAWKING Stephen Hawking, theoretical physicist and cosmologist, is remarkable in many ways. Despite challenging physical impairments, he has contributed hugely to the world of science. Hawking suffers from a type of motor neuron disease that has left him almost completely paralyzed. This did not stop him from workingon the subject of black holes and providing theories for their behavior, including the idea that they emit radiation. Hawking believed black holes to be celestial death traps that swallowed up all energy. However, he determined there was room for this phenomenon, through the merging of quantum theory, general relatively and thermodynamics, distilling it all into one path in 1974. Hawking wanted to write a book about the mysteries of the universethat would connect with the public. This task seemed impossible afterhe lost the abilities to write and speak. But Hawking did not give up,and his vision was finally realized when his ‘A Brief History of Time’ became a best seller. INDIAN ASTRONAUT (For detailed study) Wing Commander Rakesh Sharma , AC, Hero of the Soviet Union, (born 13 January 1949) is a former Indian Air Force test pilot who flew aboard Soyuz T-11 as part of the Inter cosmos program. Sharmawas the first Indian to travel in space. Kalpana Chawla: Chawla was the first Indian-born woman and the second Indian person to fly in space, She first flew on Space Shuttle Columbia in 1997 as a mission specialist and primary robotic arm operator. She had travelled 10.67 million km, as many as 252 times around the Earth logging more than 372 hours in space. Sunita Williams: Sunita Williams Pandya (born September 19, 1965). She holds the records for longest single space flight by a woman (195 days), total spacewalks by a woman (seven), and mostspacewalk time for a woman (50 hours, 40 minutes). She was assigned as a backup crew member for Expedition 30 to the International Space Station, was a crew member of Expedition 32, which launched in July 2012, and then became the Commander of Expedition 33, which began in September 2012. 33  INDIA IN SPACE The dream and realisation of spaceflight - For thousands of years, humans have curiously gazed at the night sky and dreamt oftravelling to space and explore the distant heavenly bodies there. But, that long cherished dream became a reality only after they developed large rockets capable of carrying satellites and humans tospace. After reaching space, those rockets were powerful enough to make satellites, robotic spacecraft or spacecraft carrying humans to either to circle the earth or proceed towards other worlds of our solarsystem. The uniqueness of the Indian space programme - India is one of thefew countries that have taken up the challenge of exploring space and utilising space for the benefits of common man. For this, the country has developed various technologies which few other countries have done. India’s achievements in space today are the result of the foresightedness of Dr Vikram Sarabhai, one of the greatest sons of India. Sarabhai was a great dreamer and showed the path to realise those dreams. He had firm belief in the power of space technology to bring about rapid and overall development of India. Prof Satish Dhawan, who succeeded Dr Sarabhai as the head of the Indian space programme, made immense contributions to Indian space programme by assigning great importance to developing and mastering space technologies through indigenous efforts. He also laidemphasis on the involvement of the Indian industry to meet the needs of the country’s space programme. Prof U R Rao, Dr K Kasturirangan, Dr. G Madhavan Nair and Dr K Radhakrishnan, who succeeded Prof Dhawan, have made their own unique contributions to the Indian space programme. The beginning - Though India today is considered as one of the prominent countries conducting many space activities, the Indian space programme began in a modest way with the formation of the Indian National Committee on Space Research by the Government ofIndia in 1962. The programme formally began on November 21, 1963with the launch of a 28 feet long American ‘Nike-Apache’ Sounding Rocket from Thumba, near Thiruvananthapuram. It carried a small French payload (scientific instrument) to study the winds in the upperatmosphere. Sounding rockets are small research rockets that carry instruments to study upper atmosphere and space. They cannot launch satellites. 34 India’s space capabilities- Indian space research organisation, which is widely known as ‘ISRO’, is the agency which implements the country’s space programme on behalf of the India’s Department of Space. ISRO came into existence in 1969, the same year humans set foot on the moon for the first time. Various centres of ISRO are now spread all over India. They includeVikram Sarabhai Space Centre (VSSC), situated in Thiruvananthapuram, which designs huge rockets capable of launching large satellites. In the same city is the Liquid Propulsion Systems Centre (LPSC) that develops liquid rocket engines and the more efficient and highly complex cryogenic rocket engines. Bangalore can be called as the space city of India. It has got many space related facilities including the ISRO Satellite Centre (ISAC), which builds Indian satellites are launched into space with a firm purpose like relaying the telephone calls, telecasting TV programs, taking weather pictures of the Earth or observing distant heavenly bodies. Instruments in a satellite which perform these useful tasks are called payloads. ISRO’s Space Applications Centre at Ahmedabad develops such payloads for satellites. National Remote Sensing Centre (NRSC) is another important centre of ISRO. It is situated in Hyderabad and performs the important task of receiving the pictures sent by India’s remote sensing satellites in the form of radio waves. NRSC also processes those pictures to make them accurate and show details clearly. The centre also systematically stores those pictures and distributes themin India. The island of Sriharikota in the Bay of Bengal has ISRO’s Satish Dhawan Space Centre and it is the spaceport of India. Sriharikota liesabout 80 km to the North of Chennai and lies in the Nellore district of Andhra Pradesh state. This is the place from where 38 Indian built rockets have lifted off (as on April 2013) and have travelled towards space. Some of them have launched not one but many satellites during a single launch. Sriharikota has vast facilities to manufacture large solid propellant (fuel-oxidiser combination) rockets as well as to test them. It also has facilities to assemble huge satellite launch vehicles as well as tolaunch and track them. 35  LUNAR Start End Mission Name Details date date Chandrayaan-1 was India's first lunar probe. It was launched by the Indian Space Research Organization on 22 October 2008,and operated until August 2009. The mission included a lunar orbiter and 22 28 an impactor. The mission was a major Chandrayaan-1 Oct August boost to India's space program, as 2008 2009 India researched and developed its own technology in order to explore the Moon. The vehicle was successfully inserted into lunar orbit on 8 November 2008. Chandr ayaan progra Orbiter Chandrayaan-2 was launchedfrom mme functiona the second launch pad at Satish l; the Dhawan Space lander Centre on 22 July 2019 at 2.43 PM crashed IST (09:13 UTC) to the Moonby a onto Geosynchronous Satellite Launch 22 Moon's Vehicle Mark III (GSLV Mk III). The Chandrayaan-2 July surface planned orbit has a perigee of 169.7 2019 due to km and an apogee of 45475 km. It loss of consists of a lunar orbiter, lander and control rover, all developed in India. The during main scientific objective is to mapthe the final location and abundance of lunar phase of water. descent. 36 INTER PLANNERY Mission End Start date Detail Name date s Mars Orbiter Mission (MOM), also called Mangalyaan, is a spacecraft orbiting Mars since 24 September 2014. It was launched on 5 November 2013 by the Indian Space Research Organisation (ISRO). It is Mars Orbiter 5 India's first interplanetary mission and Mission November Ongoing ISRO has become the fourth space 2013 agency to reach Mars, after the Soviet space program, NASA, and the European Space Agency. India is the first Asian nation to reach Mars orbit, and the first nation in the world to do so in its first attempt. ASTRONOMY Mission Start End Details Name date date ASTROSAT is the first dedicated Indian Astronomy satellite mission launched by ISRO on 28 September 2015, which enabled multi- wavelength observations of the celestial bodies and cosmic sources in X-ray and UV spectral 28 bands simultaneously. The scientific ASTROSAT September Ongoing payloads cover the Visible (3500– 6000 2015 Å...), UV (1300–op Å...), soft and hard X-ray regimes (0.5–8 keV; 3– 80 keV). The uniqueness of ASTROSAT lies in its wide spectral coverage extending over visible, UV, soft and hard X-ray regions. 37 INTERNATIONAL SPACE AGENCIES NASA (National Aeronautics and Space Administration) – USA NASA (National Aeronautics and Space Administration) is a space agency of the United States of America. It was established in 1958.NASA has a very important role in the exploration. NASA was the firstagency which sent first manned mission on the moon (Neil A. Armstrong, Michael Collins, Edwin E. “Buzz” Aldrin, Jr. were the firstto reach on the moon). Other successful missions of NASA are: Project Mercury (1959–63): The objective of Project Mercury wasto send man to space and during this Project first American named Alan Shepard reached there and after that John Glenn became the first American to orbit the Earth. Project Gemini (1961–66): During this mission many manned flights were flown to space.The first manned Gemini flight was flown by Gus Grissom and John Young on March 23, 1965. Project Apollo (1961–72): Project Apollo was among the most noticeable missions in the history of space exploration. The main objective of Project Apollo was to send first man to moon. In 1969 Neil A. Armstrong, Michael Collins, Edwin E. “Buzz” Aldrin, Jr. became the first to reach on the moon. Skylab (1965–79):“The dinosaurs became extinct because they didn’t have a space program. And if we become extinct because wedon’t have a space program, it’ll serve us right!”[Larry Niven] The objective of this mission was to make a space station. Skylab was the first independent space station built by the USA. The Skylabprogram was considered as greatest observatory of its time. The program included a micro-gravity lab, a medical lab, an Earth- observing facility. New technologies where also used in this programsuch as Special showers, toilets, sleeping bags, exercise equipment and kitchen facilities were designed to function in micro- gravity. If we talk about the main objective of this program, it was to study the feasibility of long duration space missions. For today’s students, Skylab is a part of history that took place long before they were born. 38 Space Shuttle program (1972–2011): The objective of Space Shuttle Program was to make reusable space vehicles. The first shuttle sent to space was Columbia on 12th April, 1981. International Space Station (1993–present) :The objective of this program was to build and maintain Space Station in collaborationwith other countries Others and MAVEN: The sky is the limit only for those who aren’t afraid to fly! [Bob Bello] MAVEN stands for Mars Atmosphere and Volatile Evolution, it will be studying the atmosphere of Mars planet while orbiting Mars. MAVEN was launched on 18th of November, 2013. MAVEN will study Mars’ upper atmosphere and its interactionswith the solar wind. Beside these program other mission were also organized by NASA like Beyond Low Earth Orbit program , Commercial Crew Program etc. Russian Federal Space Agency – Russia The historic background of the Russian space programme wasconnected with the necessity for the developments of the missiles to ensure the countries defense capability in 1946. The world history was marked by the two most significant events concerned with Russian cosmonautics. On October 4th, 1957 the world’s firstartificial satellite was launched. ROSCOSMOS also known as Russian Federal Space Agency is amongthe top space agencies of the world however it was established in 1992 after dissolution of the Soviet Union. ROSCOSMOS haven’t worked that much as Soviet Program did in its period. Some Projects that were successfully completed by Soviet Space Program: Sputnik 1: Sputnik 1 was the first artificial satellite that was sent tospace on 4th Oct, 1957. This sphere-shaped satellite had a diameter of 58 cm with four external radio antennae for radio broadcasting. Sputnik 2: After the launch of Sputnik 1. Sputnik 2 became the firstartificial satellite to send any living thing in space which was a dog named Laika. Luna Project: Luna 1,2 and 3 were among the first satellites to reach near the moon, impact on moon and get pictures of moon surface. Sputnik 5: Sputnik 5 was the first probe that bring back animals (dogs 39 named Belka and Strelka) sent to space alive back to earth. Vostok Programme: Yuri Gagarin became the first person to travelto space in Vostok 1 and after that many other successful projects ofVostok sent first women on space, first dual crew on space etc. Salyut 1: Salyut 1 was the first space station built by Russia. Mars Programme: The objective of making mars series of probes was to explore mars. During this project many Mars 2 became the first probe to impact on mars and Mars 3 became the first to land onmoon successfully. European Space Agency (ESA) European Space Agency is group of nations working together for space exploration. The members of ESA are Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Ireland, Italy,Luxembourg, Netherlands, Norway, Poland, Portugal, Romania, Spain, Sweden, Switzerland, United Kingdom, Canada. It was established in 1975 and its head quarter is in Paris, France. ESA hasvarious launch vehicles to launch their satellites in space. The highlight programs are : Ariane 5: Arianne 5 is the main launch vehicle of ESA and till now has launched 22 successful flights. It’s in service since 1997before Ariane 5, Ariane 4,3,2,1 were used. Vega: Vega is a small payload launcher of ESA which is used to sendsmall satellites to space by ESA. Beside these launch vehicles , ESA also uses Soyuz in collaboration with ROSCOSMOS. 40  ARTIFICIAL SATELLITES Any man – made object orbiting the earth is called the artificial satellite of the earth. Moon is the natural satellite of the earth and therefore an artificial satellite is sometimes called a man- made moon. Every satellite is meant for a specific purpose or a mission; a satellite can also have a multipurpose mission. Thus, every satellite mission is a complex system comprising of three main elements 1) the rocket system for lunching the satellite 2) the satellite in orbit around the earth and 3) the communication system on the earth forkeeping radio contact with the satellite. SATELLITE ORBITS The orbit of the earth, moon and an artificial satellite follow Kepler’slaw of planetary motion. Johannes Kepler (1571-1630), a German astronomer had analyzed long series of data on planetary positions and found that the orbits of planets around the sun follow the following three laws, which are called Kepler’s law. 1. Each planet travels in an elliptical orbit, with the sun atone focus of the ellipse. 2. The radius vector (that is, the imaginary line from sun to planet) of a planet sweeps out equal areas in equal periods oftime. 3. Average distance of a planet from the sun uniquely determinesthe length of time required for the planet to complete one orbital revolution around the sun. From the above laws, the following important deduction can be made. 1. the speed of the planet in its orbit is maximum when it isnearest to the sun and minimum when it is farthest from the sun. 2. the planet nearest to the sun has the shortest period and the planet farthest from the sun has the longest period. This is indeed so. Mercury, which is the nearest planet to the sun, has a period of 88 days, while Pluto, the farthest planet has a period of 248years. Kepler’s laws gave a good empirical description of planetary motions,but its physical explanation had to wait until Newton (1642- 1727) formulated the laws of motion and the laws of Universal gravitation. Newton’s law of universal gravitation states that every object exertsa force of attraction on every other object and the force between anytwo objects decreases as their 41 separation increases, varying inversely as the square of the distance between the two objects. Further, the force is proportional to the product of the masses of the objects. Orbital motion is achieved through a balance of the tendency for anobject to keep moving in a straight line and the force of gravity. Based on the above idea, Newton had suggested that if a body werethrown from the top of a high mountain in a direction parallel to earth’s surface with sufficient speed, it would follow the curvature ofthe earth. In other words, it would become a satellite of the earth. Consider a satellite orbiting around the earth. At each point on the orbit, the satellite is subjected to two equal and opposite forces. Thecentripetal force directed towards the center of the earth keeps the satellite moving in the orbit while the centrifugal force exactly equalto the centripetal force is directed in the opposite direction. Since thetwo forces are exactly equal and opposite, the satellite is in a weightless condition. This is also known as a condition of “free fall”. Due to this unusual situation, astronauts in a manned satellite experience a condition of weightlessness. For planetary exploration, spacecrafts are first launched in earth orbitand then imparted higher velocity required for escape from the gravitational force of the earth. The gravitational forces of the sun, moon, and other planets affects a spacecraft’s in an escape trajectoryand therefore the resultant path of the spacecraft can be calculated only through complex mathematics of orbital mechanics’, which requires a high-speed powerful computer. For any satellite, its orbit can be expressed by the three main orbital elements.1) the maximum distance from the earth (apogee). (2) the minimum distance from the earth. (perigee) and (3) the inclination of the orbit that is the angle between the orbital plane and the equatorial plane of the earth, orbits of satellites are generally elliptical or at the most approximately circular, with very smalldifference between the apogee and perigee. Design of a satellite. Every satellite has a mission or a purpose to be fulfilled when it is launched in its orbit. Based on the mission of the satellite the main payload and the necessary sub-systems to fulfill the mission are keptin the satellite. Any satellite system generally consists of the followingsub systems Structure or housing 42 Thermal control sub-systemPower supply sub-system Communication sub-systemOrientation sub-system Orbit control and orbit transfer sub-system Payload Structure or Housing: -The main purpose of the structure is to provide support to everything that is kept on the satellite. The structure should be strong enough to withstand the shocks and vibrations that occur during the launching of the rocket and it shouldprotect the satellite from the harsh conditions of space like hard vacuum, extreme temperatures and harmful radiations. The shape and size of the structure should be such that the satellite can be easily kept in the nose cone of the rocket. Finally, the weight of the structure should be as low as possible. Thermal control sub-system: With the help of this sub -system the temperature at various parts of the satellite can be controlled within specified limits. When a satellite is in its orbit in space, its outer surface facing the sun becomes very hot (about 100 deg C) while theopposite side in the shadow becomes as cold as -130 deg C. In spiteof such large and rapid temperature variations, the temperatures at various parts within the structure are controlled within a narrow limitwith the help of thermal control sub-system. Secondly various electronic instruments of the satellite also become hot due to electrical currents flowing within them. The thermal control system also helps to control these changes in temperature. A body gains or loses heat by three process-conduction, convection and radiation in the first and second process, a medium such as air is required around the body whereas in the third process of radiation, presence of medium is not necessary, and it can take place in vacuum. Power supply sub-system: This sub-system provides electrical power to different units of the various sub-systems and the payloads.The electrical power is normally obtained through silicon solar cells, which convert sunlight into electricity. In order to obtain sufficient power, a large number of solar cells connected together have to be placed on the outer surface of the satellite. Communication sub-system: This sub-system provides the most 43 vital link between the satellite and the ground station. Its main functions are 1. To transmit all information in the form of digitally coded radio signals to the ground station about the functioning of thesatellite and its payloads. In technical terms it is called telemetry. 2. To receive digitally coded radio signals or commands from the ground for executing specific functions on the satellite, such as switching on/off certain equipment, opening of solar panels etc. This process is called Telecommand. 3. To support the tracking operations from the ground for the determination of the orbit of the satellite. The communication sub-system consists of a radio receiver, a radio transmitter and antennas to receive and transmit radio signals. Orientation sub-system: For some purposes, a satellite requires to be oriented or stabilized in certain direction. For astronomical observations, a telescope should be pointed towards certain directionin the sky. A satellite which is stabilized by spinning, is called spin- stabilized satellite. An important advantage of a spin stabilized satellite is that its outer surface becomes evenly hot due to the solarheat radiation. Another method is three-axis stabilization technique in which three rotating wheels are kept along the three mutually perpendicular axes of the satellite. This method gives a better precision in the pointing capability of the satellite and therefore it is used in communication and earth observation satellites. For such satellites, the solar cells are kept on the panels which continuously track the sun. Orbit control and orbit transfer sub-system: The orbits of the satellites for certain specific purposes are required to be controlled as precisely as possible. For making minute changes in the orbit small rockets fixed on the satellite are used. These rockets canbe activated through commands sent from the ground to make small changes in the orbit. When the propellant of the rocket is exhausted,the orbit of the satellite cannot be carried out and the satellite cannotbe used for communication. Therefore, the amount of propellant decides the useful life of the satellite. Payload: The type of payload depends on the mission of the satellite. For scientific satellite, the payload may consist of scientific instruments of different types. The functioning of these instruments depends essentially on the support provided by the different sub systems of the satellite. If 44 everything goes well, a scientific satellite can work in space for a number of years and can give a large amount of valuable data. Foran application satellite, the payload would consist of a variety of communication equipment and antennas. Launching of a satellite: A satellite is launched in the orbit by a multi- stage rocket. In the beginning, the rocket is fired in the verticaldirection. After the rocket passes through the dense layer of the loweratmosphere (~120km), the heat shield of the rocket is separated by sending a command from the ground. The direction of the rocket is then turned towards east in such a manner that at the desired heightof the orbit, the direction of the rocket is parallel to the earth and its velocity is appropriate for the desired orbit at that height. At that time, the rocket motor/engine of the last stage of the rocket is switched off and the satellite is separated from the rocket. The satellite then enters its orbit with the appropriate velocity. The last stage of the rocket remains at the same height and follows the satellite in the same orbit. If a satellite is launched in the eastern direction, it gets the advantage of the earth’s daily rotational speed from west to east. Ground station: The main function of the ground station is to keep the radio contact with the satellite in orbit. Every ground station consists of large antennas, radio receivers, radio transmitters, tape recorders, computers and other related equipment’s. The radiosignals received from the satellite provide the telemetry data, whichconsists of two parts. One part gives the observational data from thepayload and the second part gives information on the performance of the sub-systems such as temperature values at some specific points of the satellite, electrical power available to different units of the sub-systems, directions of the satellite etc. This type of information, known as the house-keeping data, is useful to judge thelife of the satellite. The ground station is also used for sending different types of radio commands to the satellite. These commands are used to perform various tasks on the satellite like switching on/off certain equipment, firing certain rockets or the rocket motor for controlling or changingthe orbit of the satellite. The third important function of the ground station is to track the satellite to determine its orbit regularly. The orbit of a satellite can be determined by obtaining the Doppler shift in the frequency of the radio waves transmitted by the transmitter onboard the satellite. 45 Some General Aspects: After a satellite is put in its orbit, it is generally not possible to make any repairs on it. It is thereforenecessary to ensure very high quality and reliability for all the equipment’s, which are kept on the satellite. To achieve this goal all equipment’s are first tested in different simulated environmental conditions which occur during the launch phase and encountered in space. The different environmental tests are as follows; 1. Shock and vibrational test (For launch phase conditions) 2. Vacuum test (For space condition) and 3. Temperature cycling test from high to low temperature (Forin- orbit conditions) After all equipment’s pass through the above tests successfully, theyare certified worthy and are incorporated on the satellite. 46  FACTS ABOUT ROCKETS Rockets are tall, thin, round vehicle with engines which is used to transport, satellites and things to space. They think of a rocket that launches into space. “Rocket” can mean a type of engine It is important to design rockets with high specific impulse propellants and light weight structural materials. Specific impulse is determined by the nature and the quality of propellants. making the rocket body lighter, one can increase the weight payload (satellite) it can carry. To design a launch vehicle we need scientists and engineers specialising in many different subjects such as aeronautics, avionic, chemicals, composites, fabrication, propellants, propulsion, softwares, structures etc. Some rockets are huge and carry big and heavy payloads. The three –stage Saturn V rocket was 110m tall (that is, taller than a 36 – story building).It could take 129 tonne to low earth orbit and 48 tons to the moon. It had three million parts. Saturn rocket was usedin Apollo programs which took humans to the moon. Indian Rockets India has designed and flown Geosynchronous Satellite LaunchVehicle (GSLV). GSLV has put our communication satellite INSAT - 4CR into orbit. GSLV is a big vehicle. It can take a 2000 – 2500 kg class communication satellite to Orbit (GTO). Communication satellites are positioned far away at 36000 km from earth. GSLV is athree-stage vehicle: 49 metre tall, with 414 tonne lift-off weight. It has a maximum diameter of 3.4 meter at the payload fairing (heat shield). GSLV uses a cryogenic engine for the third stage. The Polar Satellite Launch Vehicle, PSLV for short, is the star performer in ISROrocket family. PSLV is capable of launching 1600 kg satellites in 620 km sun- synchronous polar orbit and 1050 kg satellite in geosynchronous transfer orbit. In the standard configuration, itmeasures 44meter tall, with a lift-off weight of 295 tonne. PSLV has four stages using solid and liquid propulsion systems alternately. Thesuccess rate of PSLV has been very 47 good. PSLV has rightfully earnedthe status of workhorse launch vehicle of ISRO. The Launch Pads Sriharikota is a barrier island off the Bay of Bengal coast located about 80 km (50 mi) north of Chennai in the southern state of Andhra Pradesh, India. It houses the Satish Dhawan Space Centre First Launch Pad, one of the two satellite launch centers in India with theother being the Thumba Equatorial rocket launching station in Thiruvananthapuram. Indian Space Research Organisation launch satellites using multistage rockets such as the Polar Satellite Launch Vehicle and the Geosynchronous Satellite Launch Vehicle from Sriharikota Originally called Sriharikota High Altitude Range SHAR, (an acronym ISRO have retained to the present day) and thenSriharikota Launching Range, Satish Dhawan Space Centre the centrewas renamed in 2002 after the death of ISRO’s former chairman Satish Dhawan. Rumbling from Thumba The rumbling from Thumba continues! At the dusk on November 21,in 1963 the first rocket took off from Thumba , marking the beginning of ‘modern rocket era’ in the country. That was a sounding rocket. Sounding rockets are research rockets: instrument carrying rockets designed to make measurements and perform scientific experimentsin the upper atmosphere. Launched into Space: Pride of Nation-SLV-3: SLV-3 is thepride of the nation; We call it a launch vehicle. Rockets which launchsatellites are called launch vehicles.SLV-3 is India’s first experimental satellite launch vehicle and was successfully launched on July 18,1980 from SHAR Centre. Space Shuttle: Rockets are normally used only once; expended, thrown away and lost after use. But, space shuttle is a craft that has been designed to be used again and again like an airplane. It has huge payload bay to ferry satellites and space station- parts to orbit.Special tiles protect the shuttle as it re-enters the earth’s atmosphere.Space Shuttles were used to carry people and cargo to the space station which is orbiting at about 300 kilometer up in the sky. 48 Satellites: In astronomy, satellite is a body that orbits a planet. There are natural satellites such as the moons and artificial (man- made) satellites such as communication satellites and space stations.The first artificial satellite was very simple but modern ones are much more complicated and versatile. There are approximately3000 satellites currently in earth’s orbits. Some of them are very small; some are dead, some are discarded. The largest one now is the International Space Station. Space Race Begins: History was made on October 4, 1957, when the Soviet Union successfully launched Sputnik – 1, humanity’s first artificial satellite on-board an R-7 Semyorka rocket. The small ball like satellite was about 58 cm in diameter and weighed only 83.6kg,and took about 98 min to complete one earth orbit in its elliptical path. It was an outstanding technological feat of the human race andit triggered new scientific, technological, political and military developments, around the world. This single event marked the dawnof the space age and the USA – USSR space race. Falling, falling and not reaching: What holds satellites in the sky? Why are they not falling? Actually, a satellite in orbit is falling towardsthe earth but continuously missing it !! The launch vehicle imparts such an appropriately high velocity to the satellite that the Earth’s gravitational pull is only just enough to bend the satellite’s path witha curvature parallel to the earth! So the satellite can never hit the earth. This is an oversimplified explanation for a circular orbit. By varying the injection velocity, orientation and location, we can get a range of orbits viz. Circular, elliptical or hyperbolic. Commanding a Satellite: A satellite cannot be left free to do everything on its own. We have to talk to and also hear from the satellite. Telemetry, tracking and command (TTC) and communication systems take care of this two way of communication and control. Commanding the satellite isthe function of TTC which can switch it ON/OFF and also receive housekeeping data through the telemetry. In space a satellite experiences a range of temperatures varying from 1300 C to 1500C. Thermal control systems protect the satellite from the extreme temperature changes. 49 Where you Are? Satellites Find Our Way: Wherever we are, navigational satellites allow us to use small electronic receivers to determine our location (longitude, latitude, and altitude) to anaccuracy within a few meters. The United States Global Positioning System (GPS) consists of up to 32 satellites in six different orbital planes. Russian, GLONASS was a fully functional navigation constellation which is being restored. The Chinese system is calledBei Dou. Europe is introducing its own version of GPS, called theGalileo Positioning System. Today, cars, trucks and aircrafts are fittedwith satellite navigation equipments that act as electronic maps androute finders. Navigational satellites havemany other applications aswell. Orbiting Wealth: INSAT: The Indian national satellite (INSAT) system which is the Geostationary orbit is one of the largest domestic communication satellite systems in the Asia- Pacific region. Established in 1983 with the commissioning of ISAT-IB, it initiated amajor revolution in India’s telecommunications sector. INSAT space segment consists of 24 satellites out of which ten are in service now. Blessing from the Heavens: INSAT Applications: INSAT has many applications which we enjoy every day. Long distance telephone connectivity, television and radio services , direct to home(DTH) services etc. make our life more comfortable.20000 very smallaperture Terminals (VSAT) have revolutionized the way we live and interact, say for e- commerce and e- governance stock exchange, banking and many other instant transactions. India has an exclusive meteorological satellite Kalpana -1 EDUSAT heralded new era in the field of distance education. Satellite based telem