CONTENTS

SCIENCE & TECHNOLOGY - II

BASICS OF SPACE SCIENCE 1. ......01-11

Terminologies Related to the ...................01 Space Science

Types of orbits .......................................03

Satellites ..............................................04

Artifi cial Satellite (Part 2- Page 10) ..........06

Launch Vehicles .....................................06

Exoplanet ..............................................09

Miscellaneous .......................................10

Unispace Nanosatellite Assembly .............10 & Training programme (UNNATI)

RAMA (Reconstituting Asteroids into .........10 Mechanical Automata)

INDIA & SPACE VOYAGE2. .............12-41

ISRO Satellite Centre (ISAC) .....................13

Liquid Propulsion System Centre (LPSC) ....14

Navigational satellites .............................15

International Space Stations (ISS) .............17

Astrosat ................................................17

Mars Orbiter Mission ..............................18

Studying the Sun ....................................18

Gravitational Waves ................................19

Indians in Space .....................................21

India’s space diplomacy: South ................22 Asia Satellite

Exploring deep space: Mission Hayabusa ...23

Drones and Governance issues: ................23

Digital Sky Platform

Tracking the s-junk: Graveyard Orbit ..........24

Space programs across the world ..............24

Miscellaneous .......................................25

ISRO’s Mission/Programme ...................... 25

NASA’s Mission/Programme .................... 26

Other Agencies Mission ........................... 33

Point Nemo ............................................. 37

NASA confi rms saturns rings will ............. 38 be gone in 100 million years

Green Propellant ...................................... 38

Interstellar Mapping and ......................... 38 Acceleration Probe

NASA Parker Solar Probe Mission ............ 38

Draft Space Activities Bill, 2017 ................ 39

Resource Prospector Mission ................... 39

GRACE Mission ........................................ 40

Gaofen – 11 ............................................ 41

Solar Orbiter Mission ............................... 41

IRNSS: NavIC ........................................... 41

Kepler’s laws of planetary motion: ............ 42

Neutrino Observatory ............................... 42

COSMOLOGY 3. & ...........................42-50 ASTROPHYSICS

Cosmos and matter: Dark matter ..............44 and Dark energy

Miscellaneous .......................................44

Einstein’s Theory of Relativity ................... 44

Einstein’s theory: Earth is a free-falling ..... 45 elevator in Sun’s gravity

Einstein Ring ........................................... 45

Sunspot Cycle ......................................... 46

Method to simulate, predict solar ............ 46 .activity over ten years developed

New Source of Neutrinos in Space ........... 46 discovered

Earth has three moons ............................. 47

Remove DEBRIS ....................................... 47

The case for making Pluto a .................... 47 planet again

Cosmic Microwave Background ............... 48 Radiation (CMBR)

Plan to Prevent Asteroid Attack ................ 48

Cooperation in the peaceful uses of ......... 48 outer space: UNISPACE+50

‘EPIC’ planet ............................................ 49

India-Based Neutrino Observatory ............ 49

Uakitite ................................................... 49

NUCLEAR TECHNOLOGY4. .............51-61

Stage I – Pressurized Heavy Water ...........54 Reactor [PHWR]

Stage II – Fast Breeder Reactor .................55

Stage III – Thorium Based Reactors ...........55

India’s Atomic Institutional Structure .........58

Terminologies ........................................62

TELECOMMUNICATIO5. N ..............62-76 TECHNOLOGY

Miscellaneous .......................................68India’s First Locally Developed ................. 68 .4G/LTE Telecom System

5G ........................................................... 68

Cyber-Physical System ............................. 70

Facial Authentication Working .................. 71

Machine to Machine Communication ........ 72

Mobile Towers are harmless : CPCB .......... 72

Adoption of Blockchain Technology ......... 73 .to Stop Bank Frauds

India’s First Blockchain District ................ 73 .in Telangana

Saposhi ................................................... 74

GravityRat Malware .................................. 74

ToneTag .................................................. 75

National Broadband Mission (NBM) .......... 76

Visible Light communication technology ... 76

Missile vs Rocket ..................................... 77

DEFENCE6. ....................................77-97

Classifi cation of Missiles .........................79

Integrated Guided Missile .......................80 Development Programme

U AVs (Unmanned Aerial Vehicles) ..............82

Submarines ...........................................85

Indian Submarines ..................................86

Miscellaneous .......................................86

Pakistan’s remote sensing satellites ........ 86 PRSS-1 and PakTes-1A

Rustom-2 ................................................ 86

Man Portable Anti-Tank Guided ............... 87 Missile (MPATGM)

Ballistic Missile Defence System .............. 87

Prithvi Air Defence (PAD) ......................... 87

Advanced Air Defence (AAD) .................... 88

K-15 Sagarika .......................................... 88

Made in India’ Artillery boost .................... 88

Advanced Towed Artillery Gun System ...... 88 (ATAGS)

Vijaya: Indigenously built patrol vessel ..... 89 commissioned by Indian Coast Guard

INS Chakra .............................................. 89

Scorpene Submarine Programme ............. 90

Maritime boundary ................................... 91

Vehicle Location Tracking Devices ........... 91 and Emergency Buttons

LCA TEJAS clears maiden mid-air ............ 92 refuelling trial

India’s First Missile Tracking Ship ............. 92

Solid Fuel Ducted Ramjet (SFDR) .............. 93

Defence Innovation Hubs ......................... 93

India’s fi rst indigenous anti-nuclear .......... 94 medical kit

Defence Industry Corridor ........................ 95

Bhabha Kavach ........................................ 95

Mission Raksha Gyan Shakti ..................... 96

Intermediate Range Nuclear Forces ......... 96 Treaty, 1987

Methanol as cooking fuel ......................... 98

Gas Hydrates or Flammable Ice ................ 98

MISCELLANEOUS7. .....................98-135

World’s fi rst hydrogen train ......................99

Repurposed Used Cooking Oil (RUCO) ........99

Hydrogen-CNG ................................. 100

Shakti Shala Solar Park .........................100

Global Centre for Nuclear Energy ............101 Partnership

Apsara – U Reactor ...............................101

Experimental Advanced ........................102 Superconducting Tokamak (EAST)

Hyperloop between Mumbai and Pune .....102

Aerogel- Super-insulating gel .................102

Thermal Battery ...................................103

India’s fi rst coal-gasifi cation fertilizer .....103 plant

Quadricycles ........................................103

Prime Minister’s Science Technology ......104 And Innovation Council (PM-STIAC)

Young Scientist Programme ...................105

Innovate India Platform .........................105

Innovation Cell .....................................106

National Statistics Day ..........................106

Children’s Science Congress ................ 107

Imprint II .............................................108

About IMPRINT India: ............................108

Bharatnet Covers 1 Lakh Gram ...............108 Panchayats

National Viral Hepatitis Control ..............109 Program

National Biopharma Mission ................ 110

Agmark Online System ....................... 111

World Intellectual Property Organization ..112 (WIPO) treaties

National Intellectual Property (IP) ..........112 Award 2019

Intellectual Property Rights Mascot .........113

GI Tag .................................................114

India to expand polar research to Arctic ...115

Deep Ocean Mission (DOM) ....................116

Glass Fibre Reinforced Gypsum Concrete .116

EyeROV TUNA India’s fi rst underwater .....117 robotic drone handed over to NPOL

Stephen Hawking .................................117

Raman Effect .......................................118

Li-Fi ...................................................118

Vaterite ..............................................119

Impact Based Forecasting Approach ...... 119

India’s fi rst engine-less train ..................120

Dry Sorbent Injection (DSI) .....................120

Microcystallites ...................................120

SARAS ................................................121

Silver Copper Telluride ..........................121

Ice VII .................................................121

Periodic Table of Chemical Elements .......121

New Element with Magnetic Properties ....122 Discovered

World’s standard defi nition of kilogram ...123 now redefi ned

Science, Technology & Innovation ..........123 Policy, 2013

Nuclear Suppliers’ Insurance Policy .........124

National Biotechnology Development ......124 Strategy, 2015-2020

Technology Vision Document, 2035 .........125

Space Vision India, 2025 .......................125

National Cyber Policy ............................126

One Time Licensing for Drugs .................126

National Data Sharing and Accessibility ..127 Policy

Saksham 2019 .....................................128

Integrated Health Information Platform ...128 (IHIP)

Bharatnet ............................................129

New India challenge ..............................130

Resource Prospector Mission .................130

National Wildlife Genetic Resource Bank ..131

NIDHI (National Initiative for .................131 Development & Harnessing Innovations)

VAJRA Faculty Scheme .........................132

Pandit Deen Dayal Upadhayay Vigyan ......132 Gram Sankul Pariyojana

Farmer Zone ........................................133

Micro Solar Dome .................................133

LOTUS HR Project .................................134

Inspire Programme ...............................135

GLONASS of Russia ..............................135

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CHAPTER

1 BASICS OF SPACE SCIENCE

Terminologies Related to the Space Science

Terms related to path of satellite Apogee: It is a point on the orbit where vertical distance of the satellite from the Earth’s surface is maximum. The maximum distance of the satellite from Earth’s surface is also called apogee of the orbit of the satellite.

Perigee: It is a point on the orbit where vertical distance of the satellite from the Earth’s surface is smallest. The smallest distance of the satellite from the Earth’s surface is also called perigee of the orbit of the satellite.

Inclination: The angle between the plane of orbit of the satellite and plane of the equator of Earth is called inclination of the orbit.

Asteroid (Minor Planet)A solid body orbiting the Sun that consists of metal and rock. Most are only a few miles in diameter and are found between the orbits of Mars and Jupiter.

Astronomical UnitIt is average distance from Earth to the Sun which is slightly less than 93 million miles,

Black HoleA Black Hole is a region of space from which nothing, including light can escape. It is called “black” because it absorbs all the light that hits it, refl ecting nothing, just like a perfect black body

According to the General theory of relativity of Albert Einstein, it is the result of the curving of space-time caused by being composed of dense mass.

Black holes have a temperature and emit radiation which makes them slowly get smaller.

Earth

ApogeePerigee

Satellite

Focal Points of ellipse

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A black hole is found by its interaction with matter. The presence of a black hole can be inferred by tracking the movement of a group of stars that orbit a region in space. Alternatively, when gas falls into a black hole caused by a companion star or nebula, the gas spirals inward, heating to very high temperatures and emitting large amounts of radiation. This radiation can be detected from earthbound and Earth-orbiting telescopes.

CoronaThe outermost layer of the atmosphere of a star, including the Sun. The corona is visible during a solar eclipse or when special adapters or fi lters are attached to a telescope to block the light from the star’s central region. The gaseous corona extends millions of kilometers from the stars surface and has a temperature in the millions of degrees

Comet A comet is a “dirty snowball” of ice and rocky debris, typically a few miles across, that orbits the Sun in a long ellipse. When close to the Sun, the warmth evaporates the ice in the nucleus to form a coma (cloud of gas) and a tail. Named for their discoverers, comets sometimes make return visits after as little as a few years or as long as tens of thousands of years.

Doppler effectThe change in the wavelength of sound or light waves caused when the object emitting the waves moves toward or away from the observer also called Doppler shift. In sound, the Doppler effect causes a shift in sound frequency or pitch (for example, the change in pitch noted as an ambulance passes). In light, an object’s visible color is altered and its spectrum is shifted toward the blue region of the spectrum for objects moving toward the observer and toward the red for objects moving away.

EclipseAn event that occurs when the shadow of a planet or moon falls upon a second body. A solar eclipse occurs when the Moon’s shadow falls upon Earth, which we see as the Moon blocking the Sun. When Earth’s shadow falls upon the Moon, it causes a lunar eclipse.

Escape velocityThe minimum velocity required for an object to escape the gravity of a massive object.

The escape velocity of earth is 11.2 km/s.

GalaxyA vast collection of stars, gas, and dust typically 10,000 to 100,000 light-years in diameter and containing billions of stars (galaxies kuklos, Greek for “circle of milk,” originally used to describe our own Milky Way).

Light-yearThe distance that light (moving at about 186,000 miles per second) travels in one year, or about 6 trillion miles.

1 light year is equal to 9.461 trillion kms.

MeteorA brief streak of light caused by a small piece of solid matter entering Earth’s atmosphere at tremendous speed (typically 20 to 40 miles per second), as it also called a “shooting star.”

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If material survives the trip through the atmosphere, it’s called a meteorite after landing on Earth’s surface.

Sunspot

A temporary dark blemish on the surface of the Sun that is a planet-size region of gas cooler than its surroundings. Sunspots can be viewed safely using a solar fi lter.

Types of orbits

Polar Orbits

A polar orbit is one in which a satellite passes above or nearly above both poles of the body being orbited (usually a planet such as the Earth) on each revolution.

These orbits have an inclination near 90 degrees. This allows the satellite to see virtually every part of the Earth as the Earth rotates underneath it. The important features of the satellites revolving in polar orbits are as follows:

A satellite in a polar orbit (called Polar satellites) will pass over the equator at a different longitude on each of its orbits.

It takes approximately 90 minutes for the satellite to complete one orbit.

These satellites have many uses like measuring ozone concentrations in the stratosphere or measuring temperatures in the atmosphere; earth mapping and observation; reconnaissance; study of weather etc.

Sun Synchronous Orbits

A satellite whose time period is such that it makes exactly an integral number of revolutions (usually 13, 14 or 15) around earth in 24 hours. After passing over a certain place on Earth, next day it will again pass over the same place at the same time of day.

While Earth spins one rotation, relative to sun in 24 hours, the satellite makes an accurately integral number of revolutions. Thus, satellite will be able to look at that place and photograph it on consecutive days in identical illumination, Sun being in the same position relative to that place.

Such an orbit is called a sun-synchronous orbit & the satellite moving in this orbit is called a sun- synchronous satellite/polar satellite.

These orbits allow a satellite to pass over a section of the Earth at the same time of day. Since there are 365 days in a year and 360° in a circle, it means that the satellite has to shift its orbit by approximately 1° per day.

These satellites orbit at an altitude between 700 to 800 km. These satellites are very important for military and remote sensing purposes.

Polar Satellite Launch Vehicle (PSLV) is the third generation launch vehicle of India.

After its fi rst launch in 1994, PSLV has proved to be reliable and versatile workhorse launch vehicle of India with 39 consecutively successful missions by June 2017.

During 1994-2017 period, the vehicle has launched 48 Indian satellites and 209 satellites for customers from abroad.

Two spacecraft – Chandrayaan-1 and Mars Orbiter Spacecraft in 2013 – were launched using PSLV

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Satellites

A satellite is a moon, planet or machine that orbits a planet or star. For example, Earth is a satellite because it orbits the sun. Likewise, the moon is a satellite because it orbits Earth. Usually, the word “satellite” refers to a machine that is launched into space and moves around Earth or another body in space.

Earth and the moon are examples of natural satellites. Thousands of artificial, or man-made, satellites orbit Earth.

Types of Satellites

Astronomical Satellites Basically they are big telescopes fl oating in space designed to observe distant space objects. They orbit above the Earth, so their vision is not clouded by the gases that make up the Earth’s atmosphere.

Astronomy satellites, therefore, can “see” into space up to ten times better than a telescope of similar strength on Earth.

The Hubble Space Telescope is an example of an astronomy satellite

By analyzing the electromagnetic spectrum, the different wavelengths of light (for example, ultraviolet, x-ray, visible spectrum, microwaves, and gamma rays) make a picture of something far away in space.

Astronomy satellites have many different applications:

They can be used to make star maps.

They can be used to study mysterious phenomena such as black holes and quasars.

They can be used to take pictures of the planets in the solar system.

They can be used to make maps of different planetary surfaces.

Communications Satellites A communications satellite is a type of artifi cial satellite that is placed in Earth’s orbit for the purpose of sending and receiving communication data between a source and destination. It is used to provide data communication and relaying services for televisions, radio, telecommunication, weather and Internet services.

The Indian National Satellite (INSAT) system is one of the largest domestic communication satellite systems in Asia-Pacifi c region with nine operational communication satellites placed in Geo-stationary orbit.

Established in 1983 today GSAT-17 joins the constellation of INSAT System consisting 15 operational satellites, namely - INSAT-3A, 3C, 4A, 4B, 4CR and GSAT-6, 7, 8, 9, 10, 12, 14, 15, 16 and 18

India’s EOS:

RESOURCESAT-1, 2, 2A CARTOSAT-1, 2, 2A, 2B, RISAT-1 and 2, OCEANSAT-2, Megha-Tropiques, SARAL and SCATSAT-1, INSAT-3D, Kalpana & INSAT 3A, INSAT -3DR are earth observation satellites

Hysis, launched in 2018 will provide hyperspectral imaging for advanced earth observation

Some important terms for exam:Chandra X-ray Observatory of NASA Hubble Space Telescope of NASA Planck Observatory of ESA AstroSat, India’s fi rst astronomical satellite

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The height of these satellites above the Earth enables the satellites to communicate over vast distances.

Earth Observation Satellites These satellites are used for observing the earth’s surface and as a result they are often termed geographical satellites.

The data is used for several applications covering agriculture, water resources, urban development, mineral prospecting, environment, forestry, drought and fl ood forecasting, ocean resources and disaster management.

Using these satellites it is possible to see many features that are not obvious from the earth’s surface, or even at the altitudes at which aircraft fl y.

Using these earth observation satellites many geographical features have become obvious and they have even been used in mineral search and exploitation.

Navigation Satellites In recent years, satellites have been used for accurate navigation .

Satellite navigation (“satnav”) means using a portable radio receiver (like a cell phone) to pick up speed-of-light signals from orbiting satellites so one can fi gure out precise position, speed and local time.

It is generally much more accurate than other forms of navigation which have to contend with pesky problems like accurate timekeeping and bad weather.

India launched its own navigation satellite in the name of IRNSS-Indian Regional Navigation Satellite System. For more details about IRNSS refer Space section.

Reconnaissance Satellites: These satellites are able to see objects on the ground and are accordingly used for military purposes. As such their performance and operation is kept secret and not publicized.

DRONES are part of reconnaissance system.

Weather Satellites As the name implies these satellites are used to monitor the weather. They have helped considerably in the forecasting of the weather and have helped provide a much better understanding not only of the underlying phenomena, but also in enabling predictions to be made.

India’s Kalpana-1 and INSAT-3A are part of this.

Student Satellites Several universities / academic institutions participate in the space related programmes as well as technology development. Satellites developed (largely for demonstration purpose) by these satellites are called Student satellites.

CARTOSAT and RISAT series, including the 2018 launched Cartosat 2E have been India’s spy satellite mostly to keep eye on China and Pakistan

Brane Craft developed by a US company is a ultra-thin spacecraft that can remove space debris by enveloping junk in the Earth’s orbit and dragging it through the atmosphere, causing it to burn.

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These institutions have shown interest in introducing education in the space technology and subsequently space sciences.

Example- ANUSAT, STUDSAT, YOUTHSAT, Jugnu, SRMSAT, PiSAT.

Artifi cial Satellite (Part 2- Page 10)

An artifi cial satellite is an object that people have made and launched into orbit using rockets. There are currently over a thousand active satellites orbiting the Earth.

Satellites vary in size. Some cube satellites are as small as 10 cm. Some communication satellites are about 7 m long and have solar panels that extend another 50 m. T

The largest artifi cial satellite is the International Space Station (ISS). The main part of this is as big as a large fi ve-bedroom house, but including solar panels, it is as large as a rugby fi eld.

Altitudes of satellitesLow Earth orbit (LEO) – from 200 to 2,000 km, for example, the ISS orbits at 400 km with a speed of 28,000 km/hour, and time for one orbit is about 90 minutes.

Medium Earth orbit (MEO) – most MEO satellites are at an altitude of 20,000 km, and time for one orbit is 12 hours.

Geostationary orbit (GEO) – 36,000 km above the Earth. Time for one orbit is 24 hours. This is to match the rotation of the Earth so that the satellite appears to stay above the same point above the Earth’s surface. This is used for many communications and weather satellites.

Types of satellitesNavigation satellites - The GPS (global positioning system) is made up of 24 satellites that orbit at an altitude of 20,000 km above the surface of the Earth.

Communication satellites - These are used for television, phone or internet transmissions, for example, the Optus D1 satellite.

Weather satellites - These are used to image clouds and measure temperature and rainfall. Both geostationary and low Earth orbits are used depending on the type of weather satellite. Weather satellites are used to help with more accurate weather forecasting.

Earth observation satellites - These are used to photograph and image the Earth. Low Earth orbits are mainly used so that a more detailed image can be produced.

Astronomical satellites - These are used to monitor and image space. A satellite such as the Hubble Space Telescope orbits at an altitude of 600 km and provides very sharp images of stars and distant galaxies. Other space telescopes include Spitzer and Chandra.

International Space Station (ISS) -This is a habitable space laboratory. At an altitude of 400 km, the ISS travels at a speed of 28,000 km/h and orbits the Earth once every 92 minutes. Scientists inside the ISS are able to perform many valuable experiments in a microgravity environment.

Launch Vehicles

Launch vehicle, in spacefl ight is a rocket-powered vehicle used to transport a spacecraft beyond Earth’s atmosphere, either into orbit around Earth or to some other destination in outer space. Practical launch

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vehicles have been used to send crewed spacecraft, uncrewed space probes, and satellites into space since the 1950s

Augmented Satellite Launch Vehicle (ASLV)Augmented Satellite Launch Vehicle (ASLV) were developed to act as a low cost intermediate vehicle to demonstrate and validate critical technologies.

ASLVs are confi gured as a 5 stage solid propellant vehicle, with a mission of orbiting 150 kg class satellites into 400 km circular orbits. The launch vehicle have weight of 40 tonnes.

Polar Satellite Launch Vehicle (PSLV)The Polar Satellite Launch Vehicle usually known as PSLV put satellites in the polar orbit

PSLV is capable of launching 1600 kg satellites in 620 km, sun-synchronous polar orbit and 1050 kg satellite in Geo-synchronous Transfer Orbit (GTO).

PSLV has earned its title ‘ the Workhorse of ISRO’ consistently delivering various satellites to Low Earth Orbits, particularly the IRS series of satellites. It can take up to 1,750 kg of payload to Sun-Synchronous Polar Orbits of 600 km altitude. The PSLV is capable of placing multiple payloads into orbit, thus multi-payload adaptors are used in the payload fairing. This allowed the feat of launching 10 satellites into different orbits in 2008.In September 2018, PSLV-C-42, the lightest version of the PSLV fl ying in its core-alone version without six strap-on motors, placed two satellites in polar orbit.This was the 12th launch of a core-alone version of the PSLV.

Cryogenic engineA cryogenic engine/ cryogenic stage is the last stage of space launch vehicles which makes use of Cryogenics.

Cryogenics is the study of the production and behaviour of materials at extremely low temperatures (below -150 degree Centigrade) to lift and place the heavier objects in space.

A cryogenic engine provides more force with each kilogram of cryogenic propellant it uses compared to other propellants, such as solid and liquid propellant rocket engines and is more effi cient.

Cryogenic engine makes use of Liquid Oxygen (LOX) and Liquid Hydrogen (LH2) as propellants which liquefy at -183°C and -253°C respectively. LOX and LH2 are stored in their respective tanks.

Geosynchronous Satellite Launch Vehicle

Geosynchronous Satellite Launch Vehicle (GSLV) is a space launch vehicle designed and developed to launch heavier satellites (more than 3 tonnes) and other space objects into Geosynchronous Transfer Orbits. While Polar Satellite Launch Vehicle (PSLV) is often used to launch less-weighing satellites

Description: GSLV have three-stage launcher with strap-on motors.

First Stage: The fi rst stage (GS1) uses the 138 tonne S139 solid rocket motor with four liquid engine strap-on motors. This stage generates maximum thrust of 4700 kilo Newton.

Second Stage: GS2

Cryogenics-based tech can be used to power long range inter-continental missiles

India’s inclusion into MTCR in 2016 recognises India as a military power

It took about 25 years, 11 fl ights and over 200 tests to indigenise these engines

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The second stage uses a liquid rocket engine which is known as Vikas engine. It generates maximum thrust of 800 kilo Newton.

Third Stage: CUS

The third stage uses a Cryogenic engine, which uses liquefi ed oxygen and hydrogen as fuel. In the initial launches, GSLV used the Russian cryogenic engine in CUS stage. These engines were made by a Russian company. In 1994, ISRO started a project called Cryogenic Upper Stage Project to develop India’s own cryogenic engine with the aim of ending its reliance on foreign cryogenic engines. The CE-7.5 is India’s fi rst cryogenic engine.

Ramjet EngineA ramjet is a form of air-breathing jet engine that uses the vehicle’s forward mo on to compress • incoming air for combus on without a rota ng compressor.

Fuel is injected in the combus on chamber where it mixes with the hot compressed air and ignites. •

A ramjet-powered vehicle requires an assisted take-off like a rocket assist to accelerate it to a speed where it begins to produce thrust.

Ramjets work most effi ciently at supersonic speeds around Mach 3 (three times the speed of sound) and can operate up to speeds of Mach 6.

However, the ramjet effi ciency starts to drop when the vehicle reaches hypersonic speeds.

Scramjet engineA scramjet engine is an improvement over the ramjet engine as it effi ciently operates at hypersonic speeds and allows supersonic combustion. Thus it is known as Supersonic Combustion Ramjet, or Scramjet.

A dual mode ramjet (DMRJ) is a type of jet engine where a ramjet transforms into scramjet over Mach 4-8 range, which means it can effi ciently operate both in subsonic and supersonic combustor modes.

Some of the technological challenges handled by ISRO during the development of Scramjet engine include the design and development of Hypersonic engine air intake, the supersonic combustor, development of materials withstanding very high temperatures, computa onal tools to simulate hypersonic fl ow, ensuring performance and operability of the engine across a wide range of fl ight speeds, proper thermal management and ground tes ng of the engines.

India is the fourth country to demonstrate the fl ight tes ng of a Scramjet Engine.

Reusable Launch Vehicle

A reusable launch system (or reusable launch vehicle, RLV) is a launch system which is capable of launching a launch vehicle into space more than once.

This contrasts with expendable launch systems, where each launch vehicle is launched once and then discarded.

Application of these technologies would bring down the launch cost by a factor of 10

ISRO has tested RSLVs

It involves many components including

Hypersonic experiment (HEX),

The Landing experiment (LEX),

Return fl ight experiment (REX),

Scramjet Propulsion experiment (SPEX).

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Exoplanet

All of the planets in our solar system orbit around the Sun. Planets that orbit around other stars are called exoplanets. Exoplanets are very hard to see directly with telescopes. They are hidden by the bright glare of the stars they orbit.

So, astronomers use other ways to detect and study these distant planets. They search for exoplanets by looking at the effects these planets have on the stars they orbit.

Space debrisSpace debris is defi ned as all non-functional, human-made objects, including fragments and elements thereof, in Earth orbit or re-entering into Earth’s atmosphere. Human-made space debris dominates over the natural meteroid environment, except around millimetre sizes.

Dead WoodTo India’s 80, there were 4,901 pieces of debris left behind by the U.S., 4,025 by Russia and 3,524 by China

Country Debris (in orbit) Debris (out of orbit)

China 3,524 1,353

Russia 4.025 15,207

U.K. 1 15

U.S. 4.901 6,325

India 80 343

Japan 55 300

France 334 733

According to European space agency in last 60 years of space activities, more than 5200 launches have placed some 7500 satellites into orbit, of which about 4300 remain in space; only a small fraction about 1200 are still operational today.

Kessler SyndromeThe Kessler syndrome (also called the Kessler effect, proposed by the NASA scientist Donald J. Kessler in 1978, is a scenario in which the density of objects in low Earth orbit (LEO) is high enough that collisions between objects could cause a cascade where each collision generates space debris that increases the likelihood of further collisions.

One implication is that the distribution of debris in orbit could render space activities and the use of satellites in specifi c orbital ranges impractical for many generations

Radio galaxies:

Radio galaxies are galaxies that emit more light at radio wavelengths than at visible wavelengths. They are also known as a radio-luminous galaxy.

In 2018, Giant Metrewave Radio Telescope (GMRT) in Pune detected farthest radio galaxy ever known.

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They are super-large galaxies with a supermassive black hole in their centre that actively accumulates gas and dust from its surroundings.

They are very rare objects in the universe.

Radio galaxies are driven by non-thermal emission (meaning emission is not because of heat).

These galaxies emit high-energy jet streams, capable of accelerating charged particles around the super massive black hole to almost the speed of light.

MISCELLANEOUS

Unispace Nanosatellite Assembly & Training programme (UNNATI)

UNNATI- (Unispace Nanosatellite Assembly & Training) programme organized by ISRO was inaugurated in Bengaluru.

UNNATI

Advanced as a capacity building programme on Nanosatellite development, it is an initiative by ISRO to commemorate the 50th anniversary of the fi rst United Nations conference on the exploration and peaceful uses of outer space (UNISPACE-50).

The programme provides opportunities to the participating developing countries to strengthen in assembling, integrating and testing of Nano satellite.

The programme aims at capacity building in satellite technology for participants from countries interested in developing space programme by providing hands-on experience in building and testing of nano satellites.

UNNATI programme is planned to be conducted for 3 years by U.R. Rao Satellite Centre of ISRO in 3 batches and will target to benefi t offi cials of 45 countries.

The primary objectives of the programme are:

To offer a simplifi ed and increased exposure to satellite fabrication technologies, as part of the UNISPACE initiative.

To provide theoretical course on satellite technology.

To provide intensive course on Nanosatellite realisation, covering mission aspects, design, fabrication, assembly, integration & testing.

To provide hands-on training to assemble, integrate and test a low cost, modular nano satellite.

RAMA (Reconstituting Asteroids into Mechanical Automata)

NASA to give funds to Made In Space’s project- RAMA (Reconstituting Asteroids into Mechanical Automata), for fi nding ways to turn asteroids into giant, autonomous spacecrafts, which could fl y to outposts in space.

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It has been designed to leverage the advancing trends of additive manufacturing (AM) and in-situ resource utilization (ISRU).

The project aims to enable asteroid rendezvous missions in which a set of technically simple robotic processes convert asteroid elements into very basic versions of spacecraft subsystems (GNC, Propulsion, Avionics).

Upon completion, the asteroid will be a programmed mechanical automata carrying out a given mission objective such as relocation to an Earth-Moon liberation point for human rendezvous.

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