Space Technology-Science and Technology Notes

Space technology refers to the application of scientific knowledge and engineering principles to explore and utilize outer space. It encompasses a wide range of technologies and systems that enable human activities in space, such as space exploration, satellite communications, weather forecasting, navigation, Earth observation, and more. Space technology has significantly advanced over the years, and it continues to play a crucial role in various aspects of modern life.

Key aspects and applications of space technology include:

Space Exploration:

Space technology is used to design and build spacecraft, rockets, and probes that explore celestial bodies, such as planets, moons, asteroids, and comets. It allows us to gather data and conduct scientific research on distant objects in the universe.

Satellite Communication:

Satellites in space facilitate global communication, enabling TV broadcasting, internet services, long-distance telephone calls, and data transmission. They play a crucial role in connecting people around the world.

Remote Sensing and Earth Observation:

Earth-observing satellites equipped with various sensors collect data on the Earth’s surface, atmosphere, oceans, and weather patterns. This data is used for environmental monitoring, disaster management, agriculture, urban planning, and more.

Global Navigation:

Satellite navigation systems, such as GPS (Global Positioning System), use space technology to provide precise positioning, navigation, and timing information for various applications, including transportation, aviation, and military operations.

Space Science and Research:

Space technology supports scientific research in fields like astronomy, astrophysics, planetary science, and cosmology. Observatories and space telescopes allow astronomers to study celestial objects and phenomena beyond Earth’s atmosphere.

Weather Forecasting:

Weather satellites equipped with advanced sensors gather real-time data on atmospheric conditions, cloud cover, and weather patterns. This data is critical for accurate weather forecasting and climate monitoring.

Space Station and Human Spaceflight:

Space technology enables human spaceflight and the operation of space stations like the International Space Station (ISS). It supports scientific experiments, technology demonstrations, and international collaboration in space.

Space Transportation:

Rockets and launch vehicles are essential components of space technology, allowing payloads, including satellites and spacecraft, to reach orbit and beyond.

Space technology has transformed the way we understand and interact with the universe, as well as how we manage various aspects of life on Earth. It continues to drive innovation, pushing the boundaries of human knowledge and expanding our capabilities both in space and on our home planet.

Indian Space Research Programme (ISRP)

ISRO is the national space agency of India for all space-based applications like reconnaissance, communications, and research. It undertakes the design and development of space rockets, and satellites, and explores upper atmosphere and deep space exploration missions.

Indian Space Centres and Space Agencies

Space Research Centers and Units are spread across India and located in various cities. They are to work hard and achieve space goals. The primary body of this field is The Department of Space. It is responsible for monitoring and regulating the Indian space program. All the other agencies and units function under it. 

Department of Space, Banglore

In 1961, Jawaharlal Nehru gave the responsibility of space research to the Department of Atomic Energy. Indian National Committee for Space Research was set up in 1962 to organize space programs.

It became the advisory body under the India National Science Academy in 1969 and then became the Indian Space Research Organization the same year. The Government of India formed a Space Commission to introduce the Department of Space.

The Department of Space (DOS) came into being in June 1972. The government of India decided to establish this department for the development of space science. Its main objective includes promoting application-based science for the development of the nation.

It is a government body to administers all the space programs. It is responsible for managing space centers and agencies across India. Here is a list of all Space Centres and Agencies functioning in India under DOS:

ISRO Centres & Units

Department of Space and ISRO HQ
Human Space Flight Centre (HSFC)
Indian Institute of Remote Sensing (IIRS)
ISRO Inertial Systems Unit (IISU)
ISRO Propulsion Complex (IPRC)
ISRO Telemetry, Tracking and Command Network (ISTRAC)
Laboratory for Electro-Optics Systems (LEOS)
Liquid Propulsion Systems Centre(LPSC)
Master Control Facility (MCF)
National Remote Sensing Centre (NRSC)
Satish Dhawan Space Centre (SDSC) SHAR
Space Applications Centre (SAC)
U R Rao Satellite Centre (URSC)
Vikram Sarabhai Space Centre(VSSC)
IN-SPACe

CPSEs

Antrix Corporation Limited
NewSpace India Limited (NSIL)
Autonomous bodies

Indian Institute of Space Science and Technology (IIST)
National Atmospheric Research Laboratory (NARL)
North Eastern-Space Applications Centre (NE-SAC)
Physical Research Laboratory (PRL)

Indian Space Research Organization (ISRO) HQ, Bangalore

ISRO is the primary research and development unit of the DoS. It is a space agency by the Indian Government. Its main motto is “harness space technology for national development while pursuing space science research & planetary exploration”.

ISRO came into being in 1969 with tremendous efforts by scientist Vikram Sarabhai. He was the first chairperson of the INCOSPAR. its headquarters is in Bangalore.

A few of the achievements of ISRO include – Polar Satellite Launch Vehicle, Geosynchronous Satellite Launch Vehicle, Aryabhata Satellite, Chandrayaan-1, Mars Orbiter Mission, etc.

Vikram Sarabhai Space Centre (VSSC), Thiruvananthapuram

It is the main technical center of ISRO and the unit for the development of the Launch Vehicle series. It supports the Rohini Sounding Rocket program. VSSc began as India’s Thumba Equatorial Rocket Launching Station but to honor Vikram Sarbahi, the name changed.

It came into being in 1963. It is the largest ISRO facility.

This center researches aeronautics, avionics, vehicle integration, chemicals, propulsion, space ordnance, space physics, and systems reliability.

Liquid Propulsion Systems Centre (LPSC), Thiruvananthapuram / Karnataka

The LPSC takes care of design development, testing, and implementation liquid propulsion packages. The production and testing of liquid stages and liquid engines for launch vehicles and satellites take place here. LPSC, Bangalore on the other hand is responsible for producing precision transducers.

Satish Dhawan Space Centre (SDSC), Sriharikota

It is a rocket launch center of ISRO. It came into being in 1971 as Sriharikota Range. SDSC was renamed after ISRO’s former chairman Satish Dhawan. It is the main launch base for India’s sounding rockets.

The location also sees India’s largest Solid Propellant Space Booster Plant and the Static Test and Evaluation Complex. This center has an integration facility, with suitable interfacing to a launchpad.

 U R Rao Satellite Centre, Bangalore

It is the unit for spacecraft projects and the main satellite technology base of ISRO. This facility is responsible for implementing indigenous spacecraft in India. The construction of satellites like Aryabhata, Bhaskara, APPLE, and IRS-1Atoo place here.

Space Applications Centre (SAC), Ahmedabad

It is responsible for aspects of the practical use of space technology. It researches geodesy, satellite-based telecommunications, surveying, remote sensing, meteorology, environment monitoring, etc.

This coordinates with Delhi Earth Station which is responsible for the demonstration of various Satellite Communication experiments and operations.

National Remote Sensing Centre (NRSC), Hyderabad

It is responsible for remote sensing of natural resources and studies aerial surveying. With ground stations at Balanagar and Shadnagar, it facilitates training at the Dehradun Indian Institute of Remote Sensing (1966).

It is an institute for higher education and training in Remote Sensing specialization.

Master Control Facility (MCF), Hassan

It is responsible for geostationary satellite orbit raising, payload testing, and in-orbit operations. It has Earth stations and the Satellite Control Centre satellite management under it. MCF came into being in 1982.

It has three internal divisions – the Spacecraft Control Centre, the Mission Control Centre, and the Earth Station. The construction of the second facility ‘MCF-B’ is going on in Bhopal. 

Antrix Corporation Limited, Bangalore

It takes care of the promotion and commercial exploitation of space products and technical consultancy services of ISRO. It also facilitates the growth of space-industrial capabilities in-country. This engages in space products and services to international customers.

They try to build connections with the customers from production till after-sale service. The National Natural Resources Management System works closely with Antrix to study operational remote sensing and meteorological satellites in operation.

New Space India Limited (NSIL), Bangalore

It came into being in 2019. This facility of ISRO is responsible for handling the commercial front of the organization. It will focus on high-technology space-related activities and promotion of the Indian space program.

ISRO Inertial Systems Unit (IISU), Thiruvananthapuram

It takes care of the Inertial Systems for Launch Vehicles and Spacecraft programs of ISRO. From designing to development, everything takes place here. Inertial Navigation Systems, Attitude Reference Systems, Rate Gyro Packages, and Accelerometer Packages are developed here.

Development and Educational Communication Unit (DECU), Ahmedabad

It is responsible for education, research, and training related to applicational space science. They work on Telemedicine, Tele-Education, and Satellite Communication.

Defense Space Agency, Bangalore

The Integrated Space Cell was an agency under the Government of India for the security of space-based military systems. This agency now goes by Defence Space Agency. The Defence Space Agency serves the Indian Armed Forces.

It operates the space warfare and Satellite Intelligence assets of India. The DSA shall protect Indian interests in outer space and potential space wars.

Physical Research Laboratory, Ahmedabad

It is the National Research Institute for space and allied sciences. It is an autonomous unit of DOS and researches – Astronomy and Astrophysics, Solar Physics, Planetary Science and Exploration, and more. This came into being in 1947 and the founder was Dr. Vikram Sarabhai.

The current director of this facility is Dr. Anil Bhardwaj. Studies of solar physics take place at the Infra-red Observatory at Mt. Abu and Solar Observatory in Udaipur. They have a suitable atmosphere to make an observation.

What Is An Orbit?

An orbit is a regular, repeating path that one object in space takes around another one. An object in an orbit is called a satellite. A satellite can be natural, like Earth or the moon. Many planets have moons that orbit them. A satellite can also be man-made, like the International Space Station.

Planets, comets, asteroids and other objects in the solar system orbit the sun. Most of the objects orbiting the sun move along or close to an imaginary flat surface. This imaginary surface is called the ecliptic plane.

Basics Of Orbit

Orbits come in different shapes. All orbits are elliptical, which means they are an ellipses, similar to an oval. For the planets, the orbits are almost circular. The orbits of comets have different shapes. They are highly eccentric or “squashed.” They look more like thin ellipses than circles.

Satellites that orbit Earth, including the moon, do not always stay the same distance from Earth. Sometimes they are closer, and at other times they are farther away. The closest point a satellite comes to Earth is called its perigee. The farthest point is the apogee. For planets, the point in their orbit closest to the sun is perihelion. The farthest point is called aphelion. Earth reaches its aphelion during summer in the Northern Hemisphere. The time it takes a satellite to make one full orbit is called its period. For example, Earth has an orbital period of one year. The inclination is the angle the orbital plane makes when compared with Earth’s equator.

An object in motion will stay in motion unless something pushes or pulls on it. This statement is called Newton’s first law of motion. Without gravity, an Earth-orbiting satellite would go off into space along a straight line. With gravity, it is pulled back toward Earth. A constant tug-of-war takes place between the satellite’s tendency to move in a straight line, or momentum, and the tug of gravity pulling the satellite back.

An object’s momentum and the force of gravity have to be balanced for an orbit to happen. If the forward momentum of one object is too great, it will speed past and not enter into orbit. If the momentum is too small, the object will be pulled down and crash. When these forces are balanced, the object is always falling toward the planet, but because it’s moving sideways fast enough, it never hits the planet. Orbital velocity is the speed needed to stay in orbit. At an altitude of 150 miles (242 kilometers) above Earth, orbital velocity is about 17,000 miles per hour. Satellites that have higher orbits have slower orbital velocities.

The International Space Station is in low Earth orbit, or LEO. LEO is the first 100 to 200 miles (161 to 322 km) of space. LEO is the easiest orbit to get to and stay in. One complete orbit in LEO takes about 90 minutes.

Satellites that stay above a location on Earth are in geosynchronous Earth orbit, or GEO. These satellites orbit about 23,000 miles (37,015 km) above the equator and complete one revolution around Earth precisely every 24 hours. Satellites headed for GEO first go to an elliptical orbit with an apogee of about 37,015 km. Firing the rocket engines at apogee then makes the orbit round. Geosynchronous orbits are also called geostationary.

Any satellite with an orbital path going over or near the poles maintains a polar orbit. Polar orbits are usually low Earth orbits. Eventually, Earth’s entire surface passes under a satellite in polar orbit. When a satellite orbits Earth, the path it takes makes an angle with the equator. This angle is called the inclination. A satellite that orbits parallel to the equator has a zero-degree orbital inclination. A satellite in a polar orbit has a 90-degree inclination.

Words to Know

Ellipse: A flattened circle or oval.

Orbital plane: An imaginary, gigantic flat plate containing an Earth satellite’s orbit. The orbital Plane passes through the center of Earth.

Momentum: The mass of an object multiplied by its velocity.

Parallel: Extending in the same direction, everywhere equidistant, and not meeting.

Types Of Orbit

Geostationary Orbit (GEO)

A geostationary orbit, also referred to as a geosynchronous equatorial orbit, is a circular geosynchronous orbit 35,786 km in altitude above Earth’s equator, 42,164 km in radius from Earth’s center, and following the direction of Earth’s rotation.

Low Earth Orbit (LEO)

A low Earth orbit is an orbit around Earth with a period of 128 minutes or less and an eccentricity less than 0.25. Most of the artificial objects in outer space are in LEO, with an altitude never more than about one-third of the radius of Earth. 

Medium Earth Orbit (MEO)

The region of space in between the low Earth orbit and the geostationary orbit is called the Medium Earth Orbit (MEO). This orbit is at a distance of 2000 to 35786 kms from the earth’s surface. This orbit is ideal for navigation and communication satellites.

Some examples of satellites that operate from this orbit include GPS (Altitude of 20,200 kilometers), GLONASS (Altitude of 19,100 kilometers) and Galileo (Altitude of 23,222 kilometers). Communication Satellites covering the North and South Pole also revolve in MEO.

The MEO satellites have an orbital period ranging from 2 to 24 hours. Telstar, the first experimental satellite launched in 1962, also orbits in MEO.

Polar Orbit And Sun-Synchronous Orbit (SSO)

A Sun-synchronous orbit, also called a heliosynchronous orbit, is a nearly polar orbit around a planet, in which the satellite passes over any given point of the planet’s surface at the same local mean solar time.

Transfer Orbits And Geostationary Transfer Orbit (GTO)

To attain geosynchronous (and also geostationary) Earth orbits, a spacecraft is first launched into an elliptical orbit with an apoapsis altitude in the neighborhood of 37,000 km. This is called a Geosynchronous Transfer Orbit (GTO).

Halo Orbit

A halo orbit is a type of stable orbit that occurs in the circular restricted three-body problem, a classical problem in celestial mechanics. In this problem, there are three massive bodies, typically a smaller primary body (e.g., a planet) and two larger secondary bodies (e.g., moons or stars), all of which interact gravitationally. The circular restricted three-body problem assumes that the two larger bodies move in circular orbits around their common center of mass, and the smaller body (e.g., a spacecraft) is affected only by their gravitational fields.

A halo orbit is a type of periodic, three-dimensional orbit that allows a spacecraft to effectively “hover” in a region around one of the Lagrange points in the system. Lagrange points are specific points in space where the gravitational forces of the two larger bodies and the centrifugal force of the smaller body all balance out, creating stable regions where objects can remain relatively stationary with respect to the two larger bodies.

Halo orbits are particularly interesting because they allow spacecraft to maintain a relatively fixed position with respect to the Lagrange point, enabling observation and study of celestial bodies or phenomena from a unique vantage point. These orbits are used in various space missions, such as for Earth observation, solar observations, and studying other planets and their moons. The James Webb Space Telescope, for example, is planned to be positioned at the second Lagrange point (L2) using a halo orbit, allowing it to have a clear view of the universe without being affected by the Earth’s shadow and heat.

Halo orbits are complex and require precise calculations and adjustments to maintain, but they offer valuable opportunities for scientific research and observation in space.

Lagrange Points

• Lagrange points are positions in space where objects sent there tend to stay put. At Lagrange points, the gravitational pull of two large masses precisely equals the centripetal force required for a small object to move with them. These points in space can be used by spacecraft to reduce fuel consumption needed to remain in position.
• Lagrange Points are positioning in space where the gravitational forces of a two-body system like the Sun and the Earth produce enhanced regions of attraction and repulsion. These can be used by spacecraft to reduce fuel consumption needed to remain in position.
• There are five special points where a small mass can orbit in a constant pattern with two larger masses. The Lagrange Points are positions where the gravitational pull of two large masses precisely equals the centripetal force required for a small object to move with them. 
• Of the five Lagrange points, three are unstable and two are stable. The unstable Lagrange points – labeled L1, L2, and L3 – lie along the line connecting the two large masses. The stable Lagrange points – labeled L4 and L5 – form the apex of two equilateral triangles that have large masses at their vertices. L4 leads the orbit of Earth and L5 follows.
• The L1 point of the Earth-Sun system affords an uninterrupted view of the sun and is currently home to the Solar and Heliospheric Observatory Satellite SOHO.
• The L2 point of the Earth-Sun system was the home to the WMAP spacecraft, current home of Planck, and future home of the James Webb Space Telescope. L2 is ideal for astronomy because a spacecraft is close enough to readily communicate with Earth, can keep Sun, Earth and Moon behind the spacecraft for solar power and (with appropriate shielding) provides a clear view of deep space for our telescopes. The L1 and L2 points are unstable on a time scale of approximately 23 days, which requires satellites orbiting these positions to undergo regular course and attitude corrections.
• NASA is unlikely to find any use for the L3 point since it remains hidden behind the Sun at all times. The idea of a hidden planet has been a popular topic in science fiction writing.
• The L4 and L5 points are home to stable orbits so long as the mass ratio between the two large masses exceeds 24.96. This condition is satisfied for both the Earth-Sun and Earth-Moon systems and for many other pairs of bodies in the solar system. Objects found orbiting at the L4 and L5 points are often called Trojans after the three large asteroids Agamemnon, Achilles and Hector that orbit in the L4 and L5 points of the Jupiter-Sun system. (According to Homer, Hector was the Trojan champion slain by Achilles during King Agamemnon’s siege of Troy). There are hundreds of Trojan Asteroids in the solar system. Most orbit with Jupiter, but others orbit with Mars. In addition, several of Saturn’s moons have Trojan companions.

Satellite

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. Some take pictures of the planet that help meteorologists predict weather and track hurricanes. Some take pictures of other planets, the sun, black holes, dark matter or faraway galaxies. These pictures help scientists better understand the solar system and universe.

Still, other satellites are used mainly for communications, such as beaming TV signals and phone calls around the world. A group of more than 20 satellites makes up the Global Positioning System or GPS. If you have a GPS receiver, these satellites can help figure out your exact location.

Why satellite doesn’t the fall at dawn?

Satellites remain in orbit around Earth because they are moving at high speeds and at just the right altitude to balance the gravitational pull of the planet with their forward velocity. This balance between gravity and centripetal force allows satellites to continuously “fall” towards Earth due to gravity while also moving forward at a sufficient speed to continually miss the planet’s surface.

Here’s how it works:

1. Gravity: The gravitational force between Earth and a satellite pulls the satellite toward the planet’s center. This force is what keeps the satellite in orbit around Earth.
2. Centripetal Force: The satellite’s forward velocity creates a centrifugal force (also called centripetal force) that opposes the pull of gravity. This force is directed outward and perpendicular to the satellite’s velocity vector.

When these two forces are balanced, the satellite’s trajectory becomes an elliptical orbit around Earth. If the satellite’s forward velocity were to decrease significantly, it would start getting closer to Earth, and if it were to increase, it would move into a higher orbit.

It’s important to note that there is still a very thin atmosphere at the outer edges of Earth’s atmosphere (in what’s known as the exosphere). Even at the relatively high altitudes where most satellites orbit, there is still some atmospheric drag. This drag slightly slows down the satellites over time, causing them to gradually lose altitude. This is one reason why some satellites have thrusters or other propulsion systems that they can use to periodically adjust their orbits and counteract the effects of atmospheric drag.

Satellites in higher orbits, such as those in geostationary orbit or deep space, experience less atmospheric drag and can remain in orbit for much longer periods without needing significant adjustments.

Space Shuttle

The Space Shuttle was a partially reusable spacecraft system operated by NASA, the United States space agency, from 1981 to 2011. It was designed to carry astronauts and payloads into low Earth orbit (LEO), perform a variety of missions including satellite deployment, scientific research, and space station construction, and then return safely to Earth.

Key components of the Space Shuttle system included:

Orbiter:

The orbiter was the main spacecraft component that carried the crew, payloads, and equipment. It was equipped with wings and could glide back to Earth for a runway landing, which was a distinguishing feature of the Space Shuttle compared to traditional capsules that performed parachute landings.

Solid Rocket Boosters (SRBs):

The Space Shuttle used two large solid rocket boosters to provide the initial thrust during liftoff. These boosters were jettisoned after burnout and recovered for refurbishment and reuse in subsequent missions.

External Tank:

The external tank was the large fuel tank located between the orbiter and the SRBs. It contained the propellants—liquid hydrogen and liquid oxygen—used by the orbiter’s main engines. The external tank was expendable and burned up upon reentry into Earth’s atmosphere.

Main Engines:

The orbiter was equipped with three main engines that used liquid hydrogen and liquid oxygen from the external tank to provide thrust for the orbiter to reach orbit.

The Space Shuttle program achieved many significant milestones, including the deployment of satellites like the Hubble Space Telescope, the construction of the International Space Station (ISS), and various scientific research missions. However, the program also faced challenges, including the tragic accidents of the Space Shuttles Challenger in 1986 and Columbia in 2003.

Due to concerns about safety, the high cost of maintaining the aging fleet, and advancements in space technology, NASA retired the Space Shuttle program in 2011 after the final mission of the orbiter Atlantis. The retirement marked a transition to using other launch vehicles and spacecraft for crew and cargo transport to and from the ISS, such as the SpaceX Crew Dragon and Boeing CST-100 Starliner.

The Space Shuttle era left a lasting impact on space exploration, technology development, and our understanding of human spaceflight.

SpaceCraft

“Spacecraft” is a broad term that refers to any vehicle designed for travel or operation in outer space. There are various types of spacecraft, each designed for specific purposes and missions. Here are a few common categories of spacecraft:

Satellites:

Satellites are spacecraft that orbit around celestial bodies, such as planets, moons, or stars. They can have various purposes, including communication, Earth observation, weather forecasting, navigation (GPS satellites), scientific research, and military surveillance.

Rovers:

Rovers are robotic vehicles designed to explore the surface of other planets, moons, or celestial bodies. They are equipped with instruments to conduct scientific experiments, capture images, and gather data. Examples include the Mars rovers like Spirit, Opportunity, Curiosity, and Perseverance.

Space Probes:

Space probes are uncrewed spacecraft designed to travel to distant destinations in our solar system and beyond. They often carry scientific instruments to study planets, asteroids, comets, and other objects. Examples include the Voyager probes, which has left our solar system, and the New Horizons probe which explored Pluto.

Space Telescopes:

Space telescopes are observatories placed in orbit to observe celestial objects without the distortion caused by Earth’s atmosphere. The Hubble Space Telescope is a famous example, providing stunning images and valuable scientific data about the universe.

Space Stations:

Space stations are habitable structures in orbit where astronauts live and work for extended periods. The International Space Station (ISS) is a collaborative project involving multiple countries and serves as a laboratory for scientific research, technology development, and international cooperation.

Crewed Spacecraft:

Crewed spacecraft are vehicles designed to carry astronauts into space. They can be used for various purposes, including space exploration, space tourism, and servicing space stations. Examples include the Russian Soyuz spacecraft, the SpaceX Crew Dragon, and the Boeing CST-100 Starliner.

Lander Modules:

Lander modules are components of spacecraft designed to land on the surface of celestial bodies. They are used for delivering equipment, rovers, or scientific instruments to explore and study the surface. For instance, the lunar landers of the Apollo missions and China’s Chang’e missions are examples of lander modules.

Sample Return Missions:

These spacecraft are designed to land on a celestial body, collect samples, and then return those samples to Earth. For example, the Hayabusa and Osiris-Rex missions collected samples from asteroids.

Interplanetary Missions:

These spacecraft are specifically designed to travel between different planets in our solar system, exploring their features, composition, and atmosphere. Mars missions, such as the Mars rovers and orbiters, fall into this category.

Rocket

A rocket is a vehicle or device that uses the principle of action and reaction, specifically Newton’s third law of motion, to propel itself by expelling exhaust gases at high speeds. Rockets operate in the vacuum of space or in Earth’s atmosphere and are used for various purposes, including space exploration, satellite deployment, scientific research, and even military applications. Rockets are crucial for enabling humans and payloads to reach outer space.

Key components of a typical rocket include:

Propellant:

Rockets use propellant, a combination of fuel and oxidizer, to generate thrust. The fuel and oxidizer react chemically or through combustion, producing hot gases and exhaust that are expelled out of the rocket’s engine nozzle. Common propellants include liquid hydrogen and liquid oxygen (used in the Space Shuttle’s main engines) or solid propellant (used in solid rocket boosters).

Combustion Chamber:

The combustion chamber is where the fuel and oxidizer are mixed and ignited. This combustion produces a high-speed stream of hot gases that expand and exit the rocket’s engine nozzle.

Nozzle:

The nozzle is designed to accelerate and shape the flow of exhaust gases, increasing their velocity and thus the thrust generated by the rocket. The nozzle’s shape is optimized based on the rocket’s design and the conditions of operation.

Payload:

The payload is what the rocket is designed to carry. It can include satellites, scientific instruments, crewed spacecraft, rovers, landers, or any other cargo destined for space. The payload is typically located at the top of the rocket.

Stages:

Rockets are often divided into stages, each containing its own engines and propellant tanks. As a stage’s propellant is depleted, the empty stage is jettisoned to reduce weight, and the next stage ignites. This multi-stage configuration allows the rocket to achieve higher speeds and altitudes.

Fairing:

The payload is often enclosed in a protective fairing or nose cone during launch to shield it from aerodynamic forces and environmental conditions. The fairing is jettisoned once the rocket reaches the upper atmosphere or space.

Guidance and Control Systems:

Rockets are equipped with systems to control their trajectory, orientation, and stability during flight. This is crucial to ensure that the rocket reaches its intended destination with accuracy.

Rockets come in various sizes and types, from small launch vehicles designed for launching small payloads into low Earth orbit, to heavy-lift rockets capable of sending large payloads or even crewed missions to distant destinations. Prominent examples of rockets include the Saturn V, Falcon 9, Delta IV, Ariane 5, and the upcoming Space Launch System (SLS). The evolution of rocket technology has been instrumental in enabling space exploration and advancing our understanding of the universe.

Missile

A missile is a guided self-propelled weapon system designed to be launched over a distance to target a specific object or location. Missiles can have various purposes, including military, defense, and even scientific research. They are propelled by engines or motors and are equipped with guidance systems to ensure accuracy in hitting their intended targets.

Missiles can be broadly categorized into different types based on their characteristics and intended use:

Ballistic Missiles:

Ballistic missiles are designed to follow a trajectory that includes an initial powered phase followed by a free-fall phase. They are usually launched into a suborbital trajectory and can be classified further into:

Short-Range Ballistic Missiles (SRBMs):

• These missiles have a relatively short range and are designed for use over shorter distances.

Medium-Range Ballistic Missiles (MRBMs):

• These missiles have a moderate range capability, covering longer distances than SRBMs but still within regional ranges.

Intermediate-Range Ballistic Missiles (IRBMs):

• These missiles have longer ranges than MRBMs, extending their reach to intercontinental distances within a specific region.

Intercontinental Ballistic Missiles (ICBMs):

• ICBMs are capable of reaching targets on different continents, traveling vast distances on a ballistic trajectory.

Cruise Missiles:

• Cruise missiles are designed to fly at lower altitudes and use aerodynamic lift for sustained flight. They are powered throughout their flight and are capable of precise targeting over longer distances. Cruise missiles can be launched from various platforms, including aircraft, ships, submarines, and ground-based launchers.

Anti-Ship Missiles:

• These are specifically designed to target naval vessels, including warships and aircraft carriers. They are optimized for sea-skimming flight and are equipped with advanced guidance systems to track and engage moving targets.

Anti-Aircraft Missiles:

• These missiles are used to intercept and destroy aircraft, helicopters, drones, or other airborne targets. They can be launched from ground-based systems, ships, or aircraft.

Surface-to-Air Missiles (SAMs):

• SAMs are designed to be launched from the ground and directed toward airborne targets, including aircraft and missiles.

Air-to-Air Missiles:

• These missiles are carried by aircraft and are used to engage other aircraft in aerial combat.

Intercept Missiles:

• These missiles are used to intercept and destroy incoming threats, such as ballistic missiles or enemy aircraft, in order to protect a region or target.

Precision-Guided Missiles:

These missiles are equipped with advanced guidance systems, such as GPS or laser guidance, to ensure accuracy in hitting specific targets, minimizing collateral damage.

Missiles have been an integral part of modern military strategy and defense systems, playing roles in deterrence, warfare, and national security. However, their use and proliferation raise ethical and humanitarian concerns, and efforts are made to control their development, deployment, and usage through international agreements and treaties.

Satellite Launching Vehicles

Launchers or Launch Vehicles are used to carry spacecraft to space. India has three active operational launch vehicles: Polar Satellite Launch Vehicle (PSLV), Geosynchronous Satellite Launch Vehicle (GSLV), and Geosynchronous Satellite Launch Vehicle Mk-III (LVM3).

Overview

PSLV is configured with four variants like 6,4,2 solid rocket strap-on motors& core-alone versions. Variants will be chosen based on the payload weights & orbit to be accomplished. PSLV has been a versatile launch vehicle deployed for launching all three types of payloads viz. Earth Observation, Geo-stationary, and Navigation. It has got highest success rate and is considered as the workhorse of ISRO.

GSLV with indigenous Cryogenic Upper Stage has enabled the launching of up to the 2-tonne class of communication satellites.

The LVM3 is the next-generation launch vehicle capable of launching a 4-tonne class of communication satellites and a 10-tonne class of payloads to LEOs. The vehicle was developed with completely indigenized technologies including the C25 cryo stage. The launch vehicle has a track record of all successful launches even from the first development flight. The Human rated LVM3 is identified as the launch vehicle for the Gaganyaan mission, which is named HRLV.

The Small Satellite Launch Vehicle (SSLV) is being developed with complete indigenous technologies to meet the small satellite lunch market on demand driven basis

In order to achieve high accuracy in placing satellites into their orbits, a combination of accuracy, efficiency, power, and immaculate planning is required. ISRO’s Launch Vehicle Programme spans numerous centers. Vikram Sarabhai Space Centre, located in Thiruvananthapuram, is responsible for the design and development of launch vehicles. Liquid Propulsion Systems Centre and ISRO Propulsion Complex, located at Valiamala and Mahendragiri respectively, develop the liquid and cryogenic stages for these launch vehicles. Satish Dhawan Space Centre, SHAR, is the spaceport of India and is responsible for the integration of launchers. It houses two operational launches for launching ISRO’s launch vehicles.

Launchers under usage:

Polar Satellite Launch Vehicle (PSLV)

Geosynchronous Satellite Launch Vehicle (GSLV)

Geosynchronous Satellite Launch Vehicle Mark III (LVM3)

Sounding Rockets

Launchers under development:

Human Rated Launch Vehicle (HRLV)

Small Satellite Launch Vehicle (SSLV)

Reusable Launch Vehicle – Technology Demonstrator (RLV-TD)

Scramjet Engine – TD

Launchers, Retired:

SLV-3

ASLV

Satellite Launch Vehicle (SLV)

The Satellite Launch Vehicle or SLV was a small-lift launch vehicle project started in the early 1970s by the Indian Space Research Organisation to develop the technology needed to launch satellites. SLV was intended to reach a height of 400 kilometers and carry a payload of 40 kg.

Augmented Satellite Launch Vehicle (ASLV)

The Augmented Satellite Launch Vehicle or Advanced Satellite Launch Vehicle was a small-lift launch vehicle five-stage solid-fuel rocket developed by the Indian Space Research Organisation to place 150 kg satellites into LEO.

Polar Satellite Launch Vehicle (PSLV)

The Polar Satellite Launch Vehicle (PSLV) is the third generation launch vehicle of India. It is the first Indian launch vehicle to be equipped with liquid stages. After its first successful launch in October 1994, PSLV emerged as a reliable and versatile workhorse launch vehicle in India. The vehicle has launched numerous Indian and foreign customer satellites. Besides, the vehicle successfully launched two spacecraft “Chandrayaan-1 in 2008 and Mars Orbiter Spacecraft in 2013″ that later traveled to Moon and Mars respectively. Chandrayaan-1 and MOM were feathers in the hat of PSLV. The launch of PSLV-C48 marks the 50th Launch of PSLV. Besides, the vehicle successfully launched two spacecraft ” Chandrayaan-1 in 2008 and Mars Orbiter Spacecraft in 2013″ that later traveled to Moon and Mars respectively

PSLV earned its title ‘the workhorse of ISRO’ through consistently delivering various satellites into low earth orbits, particularly the IRS Series of satellites

Due to its unmatched reliability, PSLV has also been used to launch various satellites into Geosynchronous and Geostationary orbits, like satellites from the IRNSS Constellation

The PSLV is capable of placing multiple payloads into orbit, thus multi-payload adaptors are used in the payload fairing. The payload performance of the vehicle and mission flexibility is evident from the challenging missions where multi-orbit and multi-satellite missions are accomplished. The long string of consecutive successes and multi-satellite launch capability has reinforced the status of PSLV as a reliable, versatile, and affordable launcher in the global market

GSLV

LVM3 is configured as a three-stage vehicle with two solid strap-on motors (S200), one liquid core stage (L110), and a high-thrust cryogenic upper stage (C25). The S200 solid motor is among the largest solid boosters in the world with 204 tonnes of solid propellant. The liquid L110 stage uses a twin liquid engine configuration with 115 tonnes of liquid propellant, while the C25 Cryogenic upper stage is configured with the fully indigenous high thrust cryogenic engine (CE20) with a propellant loading of 28 tons. The overall length of the vehicle is 43.5 m with a gross lift-off weight of 640 tonnes and a 5m-diameter payload fairing.

LVM3 is the new heavy-lift launch vehicle of ISRO for achieving a 4000 kg spacecraft launching capability to GTO (Geosynchronous Transfer Orbit) in a cost-effective manner. LVM3 is a three-stage launch vehicle consisting of two solid propellant S200 strap-ons and core stages comprising of L110 liquid stage, the C25 cryogenic stage, the equipment bay (EB), and the Encapsulated assembly (EA). EA comprises of the spacecraft, Payload Adaptor (PLA), and the Payload fairing (PF). With a lift-off mass of 640 tons, this 43.5 m tall three-stage launch vehicle gives ISRO full self-reliance in launching heavier communication satellites that weigh up to 4000 kg in GTO. The vehicle takes off with the simultaneous ignition of the two S200 boosters. The core stage (L110) is ignited at about 113s through the flight, during the firing of the S200 stages. Both S200 motors burn for about 134s and the separation occurs at 137s. The payload fairing is separated at an altitude of 115 km and at about 217s during L110 firing. The L110 burnout and separation and C25 ignition occur at 313s. The spacecraft is injected into a GTO (Geosynchronous Transfer Orbit) orbit of 180×36000 km at a nominal time of 974.

Earth Observation Satellites

Earth observation satellites are spacecraft designed and equipped to gather data and images of the Earth’s surface, atmosphere, oceans, and various natural and human-made phenomena from space. These satellites play a crucial role in monitoring and understanding our planet, supporting a wide range of applications in areas like environmental monitoring, disaster management, agriculture, urban planning, climate studies, and more.

Key features and capabilities of Earth observation satellites include:

Remote Sensing Instruments:

Earth observation satellites are equipped with various remote sensing instruments, such as optical sensors, radar systems, and infrared detectors. These instruments capture data in different parts of the electromagnetic spectrum, allowing them to sense various characteristics of the Earth’s surface and atmosphere.

High-Resolution Imaging:

Optical sensors on Earth observation satellites capture high-resolution images of the Earth’s surface. These images provide detailed information about land cover, land use, urban development, vegetation health, and changes over time.

Radar Imaging:

Radar instruments on some satellites use microwave signals to penetrate clouds and gather data regardless of weather conditions. This capability is particularly valuable for all-weather imaging and monitoring, as well as for mapping surface features like topography and soil moisture.

Multi-Spectral and Hyper-Spectral Imaging:

Some satellites have sensors capable of capturing data in multiple spectral bands, providing insights into specific features like vegetation health, water quality, and mineral composition.

Continuous Monitoring:

Earth observation satellites are typically placed in orbit around the Earth, allowing them to provide continuous monitoring and repeat observations of specific areas. This capability is essential for tracking changes over time and detecting trends and patterns.

Environmental Monitoring:

Earth observation satellites contribute to monitoring environmental factors, such as deforestation, land degradation, pollution, and changes in ice cover. This information is crucial for conservation efforts and sustainable resource management.

Disaster Management:

During natural disasters like hurricanes, floods, wildfires, and earthquakes, Earth observation satellites provide real-time data and imagery to support disaster response and relief efforts.

Weather Forecasting:

Satellite data is essential for weather forecasting, as it provides information on cloud cover, temperature, humidity, and atmospheric conditions that affect weather patterns.

Climate Studies:

Earth observation satellites contribute to climate studies by monitoring changes in the Earth’s climate system, including sea-level rise, glacier retreat, and variations in the Earth’s energy balance.

Numerous space agencies and organizations operate Earth observation satellites, including NASA, ESA, NOAA, JAXA, ISRO, and others. The data collected by these satellites is made available to scientists, researchers, governments, and the public, supporting informed decision-making and fostering global collaboration in addressing environmental and societal challenges.

• Earth observation satellites are satellites equipped with remote sensing technology. Earth observation is the gathering of information about Earth’s physical, chemical, and biological systems.
• Many earth observation satellites have been employed in sun-synchronous orbit
• Other earth observation satellites launched by ISRO include RESOURCESAT- 2, 2A, CARTOSAT-1, 2, 2A, 2B, RISAT-1 and 2, OCEANSAT-2, Megha-Tropiques, SARAL and SCATSAT-1, INSAT-3DR, 3D, etc.

Recent Launches

NAVIC

Satellites for navigation services to meet the emerging demands of Civil Aviation requirements and to meet the user requirements of positioning, navigation, and timing based on the independent satellite navigation system.

GPS Aided Geo Augmented Navigation (GAGAN)

To meet the navigation requirements of civil aviation, ISRO and the Airports Authority of India (AAI) have implemented the GPS Aided Geo Augmented Navigation – GAGAN as a satellite-based augmentation system (SBAS) for the Indian airspace.GAGAN system is inter-operable with other international SBAS systems like USWAAS, European EGNOS, Japanese MSAS etc. GAGAN provides the additional accuracy, availability, and integrity necessary for various phases of flight, from en-route through approach for all qualified airports within the GAGAN service volume. GAGAN has been certified by the Directorate General of Civil Aviation (DGCA) for RNP 0.1 services on 30th Dec 2013 and APV -1 services on 21st April 2015. More details regarding the GAGAN system and its applications are available at the GAGAN website GAGAN

Navigation with Indian Constellation (NavIC)

To meet the positioning, navigation, and timing requirements of the nation, ISRO has established a regional navigation satellite system called Navigation with Indian Constellation (NavIC). NavIC was erstwhile known as Indian Regional Navigation Satellite System (IRNSS).

NavIC is designed with a constellation of 7 satellites and a network of ground stations operating 24 x 7. Three satellites of the constellation are placed in geostationary orbit, at 32.5°E, 83°E, and 129.5°E respectively, and four satellites are placed in inclined geosynchronous orbit with equatorial crossing of55°E and 111.75°E respectively, with an inclination of 29° (two satellites in each plane). The ground network consists of a control center, precise timing facility, range and integrity monitoring stations, two-way ranging stations, etc.

NavIC offers two services: Standard Position Service (SPS) for civilian users and Restricted Service (RS) for strategic users. These two services are provided in both L5 (1176.45 MHz) and S-band (2498.028 MHz). NavIC coverage area includes India and a region up to 1500 km beyond Indian boundary. NavIC signals are designed to provide user position accuracy better than 20m (2) and timing accuracy better than 50ns (2).NavIC SPS signals are interoperable with the other global navigation satellite system (GNSS) signals namely GPS, GLONASS, Galileo, and BeiDou

NISAR

NASA-ISRO SAR (NISAR) is a Low Earth Orbit (LEO) observatory being jointly developed by NASA and ISRO. NISAR will map the entire globe in 12 days and provide spatially and temporally consistent data for understanding changes in Earth’s ecosystems, ice mass, vegetation biomass, sea level rise, groundwater, and natural hazards including earthquakes, tsunamis, volcanoes, and landslides. NISAR. It carries L and S dual-band Synthetic Aperture Radar (SAR), which operates with the Sweep SAR technique to achieve large swaths with high-resolution data. The SAR payloads mounted on Integrated Radar Instrument Structure (IRIS) and the spacecraft bus are together called an observatory. Jet Propulsion Laboratories and ISRO are realizing the observatory which shall not only meet the respective national needs but also will feed the science community with data encouraging studies related to surface deformation measurements through the repeat-pass InSAR technique.

This flagship partnership would have major contributions from both agencies. NASA is responsible for providing the L-Band SAR payload system in which the ISRO supplied S-Band SAR payload and both these SAR systems will make use of a large size (about 12m diameter) common unfurl able reflector antenna. In addition, NASA would provide engineering payloads for the mission, including a Payload Data Subsystem, High-rate Science Downlink System, GPS receivers, and a Solid State Recorder.

GAGANYAAN

The primary mandate of HSFC is to spearhead ISRO’s Gaganyaan programme through coordinated efforts and focus all the activities that are carried out in other ISRO centers, research labs in India, Indian academia, and Industries towards accomplishing the mission. HSFC, as the lead Centre for Human space flight activities conforms to high standards of reliability and human safety in undertaking R&D activities in new technology areas, such as life support systems, Human Factors Engineering, Bioastronautics, Crew training, and Human rating & certification. These areas would constitute important components for future sustained human space flight activities like rendezvous and docking, space station building, and interplanetary collaborative manned missions to Moon/Mars and near-earth asteroids.

Gaganyaan Project

Gaganyaan project envisages a demonstration of human spaceflight capability by launching a crew of 3 members to an orbit of 400 km for a 3 days mission and bringing them back safely to earth, by landing in Indian sea waters.

The project is accomplished through an optimal strategy by considering in-house expertise, the experience of Indian industry, the intellectual capabilities of Indian academia & research institutions along with cutting-edge technologies available with international agencies. The pre-requisites for the Gaganyaan mission include the development of many critical technologies including a human-rated launch vehicle for carrying the crew safely to space, a Life Support System to provide an earth-like environment to the crew in space, crew emergency escape provision and evolving crew management aspects for training, recovery and rehabilitation of crew.

Various precursor missions are planned for demonstrating the Technology Preparedness Levels before carrying out the actual Human Space Flight mission. These demonstrator missions include Integrated Air Drop Tests (IADT), Pad Abort Tests (PAT), and Test Vehicle (TV) flights. The safety and reliability of all systems will be proven in unmanned missions preceding manned missions.

Human-rated LVM3 – HLVM3

LVM3 rocket – The well-proven and reliable heavy lift launcher of ISRO, is identified as the launch vehicle for the Gaganyaan mission. It consists of the solid stage, liquid stage, and cryogenic stage. All systems in the LVM3 launch vehicle are re-configured to meet human rating requirements and christened Human Rated LVM3. HLVM3 will be capable of launching the Orbital Module to an intended Low Earth Orbit of 400 km.

HLVM3 consists of a Crew Escape System (CES) powered by a set of quick-acting, high burn rate solid motors which ensures that the Crew Module along with the crew is taken to a safe distance in case of any emergency either at the launch pad or during the ascent phase.

Project NETRA

 ‘Project NETRA’ is an early warning system in space to detect debris and other hazards to Indian satellites.

Once operational, it will give India its own capability in Space Situational Awareness (SSA) like the other space powers.

Need: With countries launching more and more satellites, each one of them is a strategic or commercial asset, and avoiding collisions could become a challenge in the future.

For protecting its space assets, the ISRO was forced to perform 19 Collision Avoidance Manoeuvres (CAM) in 2021.

Modus Operandi: Under NETRA, the ISRO plans to put up many observational facilities: connected radars, telescopes, data processing units, and a control center.

Benefits: NETRA can spot, track, and catalogue objects as small as 10 cm, up to a range of 3,400 km, and equal to a space orbit of around 2,000 km.

The NETRA effort would make India a part of international efforts toward tracking, warning about and mitigating space debris.

More importantly, the SSA also has a military quotient to it and adds a new ring to the country’s overall security, against attacks from air, space or sea.

This is a vital requirement for protecting our space assets and a force multiplier.

BHUVAN 3.0

An upgraded geo-imaging web portal, Bhuvan Panchayat 3.0 was launched during the National Workshop on “Space-based Information Support for Decentralised Planning-2″.

The launch is part of the advanced Space-based Information Support for Decentralised Planning (SISDP) project.

The SISDP was launched in 2011 and its first phase of making databases was completed in 2017.

Key Points

• The portal uses high-resolution data from recent earth observation satellites and offers detailed information to panchayats about their key assets.
• For the first time, the thematic maps of 1:10,000 scale have been generated based on high-resolution data given by Indian Space Research Organisation’s (ISRO) new earth observation satellites.
• It is jointly implemented by the Ministry of Panchayati Raj and the Department of Space, ISRO.
• Advantages
• Decentralised Planning: “Bhuvan Panchayats” is facilitating decentralized planning at the grassroots level. E.g.: It is possible for rural planners to plan and locate a healthcare unit, water harvesting, and rural communication network even as they sit in panchayat offices.
• Empowering the Panchayats: The workshop addressed modalities and mechanisms that would be adopted to empower the local bodies in utilizing the space technology in the form of simple-to-use maps, location-based services through Navigation in Indian Constellation (NavIC) and high-resolution space images based local tools to enable the panchayats with modern technology for sustainable development.
• Technology and Governance: The Panchayati Raj institutions could effectively use space technology for planning, implementation, monitoring, and management of resources, including governance.
• Digital India: It can also prove to be an important component for the “Digital India” platform for reaching digital thematic maps to about 2.56 Lakh Gram panchayats in the country.

      Bhuvan Portal

• Bhuvan (Sanskrit for Earth) is a Geoportal of ISRO, allowing a host of services covering visualization, free data download, thematic map display and analysis, timely information on disaster and project-specific GIS applications.

• The portal was launched in 2009 and is available in English, Hindi, Tamil and Telugu.
• Bhuvan, as a platform, is open and can be used by a diverse user community such as Central and State Governments Departments, Academia, and Industry. A few examples are:
• Bhuvan-Bhujal: Ground Water Prospects Information System
• School Bhuvan: An e-learning portal for the students
• ENVIS program of Ministry of Environment, Forests & Climate Change
• Bhuvan Ganga: Enables people participation in providing vital information for Clean Ganga project
• Srishti-Drishti: An Integrated Watershed Development Program

MASS ORBITER MISSION

Mangalyaan, 2014

a) India joined an exclusive global club when it successfully launched the Mars Orbiter Mission

b) a Budget that was at least 10 times lower than a similar project by the US

c) The Rs 450-crore project revolved around the Red Planet and collecting data on Mars’atmosphere and mineral composition

Mission Shakti

Mission Shakti is a joint programme of the Defence Research and Development Organisation (DRDO) and the Indian Space Research Organisation (ISRO).

As part of the mission, an anti-satellite (A-SAT) weapon was launched and targeted an Indian satellite that had been decommissioned. Mission Shakti was carried out from DRDO’s testing range in Odisha’s Balasore.

 Significance:

India is only the 4th country to acquire such a specialized and modern capability, and the Entire effort is indigenous. Till now, only the US, Russia, and China had the capability to hit a live target in space.

Seven Mega Missions By ISRO

 ISRO (Indian Space Research Organisation) had several ambitious projects and missions on its agenda, commonly known as “Seven Mega Missions.” These missions aimed to explore various aspects of space research and push the boundaries of India’s space capabilities. However, it’s important to note that plans and missions can evolve over time, and there might have been updates or changes since then. 

Gaganyaan – Human Spaceflight Mission:

Gaganyaan is India’s ambitious project to send astronauts into space. The mission aims to demonstrate India’s human spaceflight capabilities and make the country self-reliant in crewed missions.

Chandrayaan-3 – Lunar Exploration Mission:

Following the success of Chandrayaan-1 and Chandrayaan-2, Chandrayaan-3 was planned to be the third lunar exploration mission. It aimed to further study the Moon’s surface and conduct a soft landing.

Mangalyaan-2 – Mars Orbiter Mission 2:

Building on the success of the Mars Orbiter Mission (Mangalyaan), Mangalyaan-2 was intended to explore Mars further and conduct more in-depth research on the planet.

Shukrayaan-1 – Venus Exploration Mission:

Shukrayaan-1 was proposed to be India’s first mission to Venus, aimed at studying the planet’s atmosphere and surface to gain insights into its geology and climate.

Aditya-L1 – Solar Mission:

Aditya-L1 was designed to study the Sun’s outermost layer, the corona, and investigate solar activities that have implications for space weather.

RISAT Series – Radar Imaging Satellite Missions:

The Radar Imaging Satellite (RISAT) series is focused on providing all-weather surveillance using synthetic aperture radar for agricultural, forestry, and disaster management purposes.

XPOSAT – X-ray Polarimetry Satellite:

The X-ray Polarimetry Satellite was proposed to study polarized X-rays from various cosmic sources, enhancing our understanding of high-energy astrophysical processes.

About Xposat:

The X-ray Polarimeter Satellite (or Xposat), is ISRO’s dedicated mission to study polarization. It will launch in 2020.

It will be a five-year mission and will study cosmic radiation.

It will be carrying a payload named ‘polarimeter instrument in X-rays’ (POLIX) made by Raman Research Institute. POLIX will study the degree and angle of polarisation of bright X-ray sources in the energy range of 5-30 keV.

The spacecraft will be placed in a circular 500-700km orbit.

Aditya- L1 mission:

 It is India’s first solar mission.

Objectives: It will study the sun’s outermost layers, the corona and the chromospheres and collect data about coronal mass ejection, which will also yield information for space weather prediction.

Significance of the mission: The data from Aditya mission will be immensely helpful in discriminating between different models for the origin of solar storms and also for constraining how the storms evolve and what path they take through the interplanetary space from the Sun to the Earth.

Position of the satellite: In order to get the best science from the sun, continuous viewing of the sun is preferred without any occultation/ eclipses and hence, Aditya- L1 satellite will be placed in the halo orbit around the Lagrangian point 1 (L1) of the sun-earth system.

Chandrayan-3 

Chandrayaan-3 is India’s third moon mission and is a follow-up of Chandrayaan-2 (2019) which aimed to land a rover on the lunar South Pole. The Mission will have three major modules- the

Propulsion module ( will carry the lander and rover configuration till 100 km lunar orbit)

Lander module (capability to soft land and deploy Rover)

Rover (will carry out in-situ chemical analysis of the lunar surface)

Challenges of landing on the South Pole:

Previous spacecraft have mostly landed near the equatorial region of the Moon, a few degrees latitude north or south of the lunar equator. Landing near the equator is easier and safer due to the hospitable terrain, smooth surface, absence of steep slopes, and ample sunlight for solar-powered instruments.

The lunar south pole, on the other hand, presents a challenging terrain with extreme temperatures and areas that are in permanent shadow, receiving no sunlight.

Why ISRO wants to explore the Moon’s south pole?

Water Resources: The south pole region is believed to have water molecules in substantial amounts, possibly trapped as ice in the permanently shadowed craters.

Exploring and confirming the presence of water is essential for future human missions and the potential utilization of lunar resources.

Scientific Discoveries: The extreme environment and the presence of permanently shadowed regions provide a preserved record of the Moon’s history and the early Solar System.

Clues to Earth’s History: The Moon is thought to have formed from debris generated by a giant impact between a Mars-sized object and the early Earth.

By studying the lunar south pole, scientists can gain insights into the materials and conditions that existed during the formation of the Earth-Moon system.

Global Collaborations: ISRO-NASA successfully confirmed the presence of water from the data taken by Chandrayaan-1. Indo-Japan collaboration, LUPEX aims to send a lander and rover to the Moon’s south pole around 2024.

Technological Advancements: By undertaking missions to this region, ISRO can develop and demonstrate innovative technologies for soft landing, navigation, resource utilization, and long-duration operations that can be applied in future space missions.

Comparision of  Chandrayaan-1, 2 and 3

Mission	Chandrayaan-1	Chandrayaan-2	Chandrayaan-3
Launch Year	2008	2019	Scheduled for 2023
Objectives	Study lunar surface	Study the lunar surface and land rover on the lunar South Pole	Demonstrate landing capabilities for Lunar Polar Exploration Mission
Components	Orbiter, Moon Impact Probe	Orbiter, Lander (Vikram), Rover (Pragyan)	Propulsion module, Lander, Rover
Findings	Confirmed presence of lunar water, lunar caves, tectonic activity, faults, and fractures	Building on the evidence of water molecules shown by Chandrayaan-1	–
Communication	Communication issues after 312 days of operation	Lander crash-landed, rover unable to operate	–
Launch Vehicle	PSLV	GSLV-Mk 3	LVM3
Landing Site	–	Lunar South Pole	Lunar South Pole
Major Partners	–	–	Japan (for Lunar Polar Exploration Mission)

About LVM3:

Launch Vehicle Mark 3 (LVM3) (previously known as GSLV-MK III) is a three-stage launch vehicle consisting of two solid propellants S200 strap-ons on its sides and a core stage comprising L110 liquid stage and C25 cryogenic stage. The vehicle is also dubbed as one of the heaviest for its ability to carry satellites up to 8,000 kg.

India’s Space Policy 2023

The objective of Indian Space Policy 2023 is to allow, motivate and introduce a thriving commercial existence in space. It recommends the participation of the private sector in the space industry and enables them to perform end-to-end activities including building satellites, rockets, launch vehicles, data procurement, and dissemination.

The policy will introduce four different, but correlated sector, that will enable the greater participation of private entity activities that is the traditional domain of the ISRO.

• InSPACe (Indian National Space Promotion and Authorisation Centre) is a single window clearance and authority body that deals with launching space, building launch pads, purchasing and selling satellites, and spreading high-resolution data among other activities. With this, it shared products, and technology, and is best measured with NGEs and government entities.
• The primary responsibility of New Space India Limited (NSIL) is to commercialize space technologies and platforms formed through public expenses, manufacturing, leasing, or collecting space elements, technologies, and various other assets from both private and public entities.
• The Department of Space offers comprehensive policy guidelines and is the nodal department for executing space technologies. Along with this, they are responsible for coordinating international cooperation and coordination in the field of global space governance. They also form a proper mechanism to address and solve disputes of space activity.

Importance of private sector participation in space sector

• It has been observed that India is far behind in the Space Economy. The current value of the global space economy is 360 billion USD. With this, India is only 2% of the global space economy even after being one of the few spacefaring countries in the world and the space policy will help enhance it up to 10% in the future.
• Presently, the budget of ISRO amounts to USD1.6 billion approximately, while the economy of Indian space is USD9.6 billion. With this, Broadband, OTT, and 5G have committed tremendous annual growth in the satellite-based sector.
• It is anticipated that with the validating environment, the Indian space industry could witness a growth of up to USD 60 billion by 2030. This would directly create employment of two lahks or above jobs.
• It has been witnessed that the Private Sector has transformed the space sector. Various companies like SpaceX, Blue Origin, and Virgin Galactic played a pivotal role in transforming the space sector by minimizing the costs and turnaround duration. On the other hand In India, players in the private space industry have been restricted to be vendors or suppliers to the space policy of the government.
• The expenses of security and defense agencies are around a billion dollars annually to obtain earth observation data and imagery through foreign sources. This proves its dependence on foreign sectors which could be risky for India’s security.
• Promoting private sector activity in high-level technology areas, including space, is very important. This will be helpful in showcasing the true potential of India’s youth and business owners. To fulfill this vision, it is important to allow the entry of private entities into the Indian space sector so that they can work as independent players who have the ability to perform end-to-end space activities.
• The promotion of the private entity will allow the Indian space program to manage cost effectively within the global space industry which would lead to the creation of a plethora of employment opportunities in the space and other similar sectors.
• Private entities are often more flexible than government agencies. This allows them to respond effectively and quickly to changing market requirements and technological advancements.

What is the role of the private sector in the Indian Space Policy 2023?

The NGEs which involve the private entity have the authority to perform end-to-end activities in the space industry by establishing and operating space objects, ground-based assets, and similar activities including communication, remote sensing, navigation, etc. Satellites could be self-employed, obtained, or leased. The communication services can be spread over India or abroad and remote sensing data can be distributed in India or outside.

Furthermore, NGEs can also design and handle launch vehicles for space transportation and build their own infrastructure. In broader terms, the entire range of space activities can be accessed by the private sector. Security agencies can give tasks to NGEs for finding solutions to fulfill certain requirements.

Significance of Indian Space Policy 2023

Some of the key significance of the Indian space policy 2023 are shared below:

• The policy will create space industry standards, encourage identified space activities, and operate with academia to broaden the space ecosystem and allow industry-academia linkages.
• The primary focus of ISRO is to perform research into outer space. This will result in establishing advanced space technologies and applications to create India’s edge in the field of space infrastructure, space applications, space transportation, and similar areas,
• To increase the space capabilities, allow, motivate, and introduce a thriving commercial existence in space, use space as a driver of technology evolution and get benefits in allied areas, maintain international relations, and build an ecosystem to execute space applications among all stakeholders.

What are the gaps in the Indian Space Policy 2023?

The policy has given a good role for IN-SPACe but has not provided time duration for the required steps ahead. With this, there is no time frame for ISRO’s change its present practices and also there is no proper timetable for IN-SPACe to establish its regulatory framework. Therefore, the policy framework requires clear guidelines related to various activities as the IN-SPACe is a regulatory organization but does not have any legislative authority.

IN-SPACe is also likely to permit space activities for government and non-government entities. However, its position is vague as its duties are under the authority of the Department of Space.

How to fill gaps in Indian Space Policy 2023?

The Indian Space Policy 2023 is an innovative and progressive document that indicates a great vision and objectives. However, it is not sufficient. There is a need for a time frame to offer the required legal framework that would convert the vision into reality and launch India into the Second Space Age successfully.

Thus, it is important for the government to introduce a bill that provides statutory status to IN SPACe and also specifies the time frame for ISRO and IN SPACe. The bill should solve the vagueness pertaining to Foreign Investment, and support of the government to the new space startups.

Milestones In India’s Space Programme 

Space research activities were initiated in India during the early 1960s when applications using satellites were in experimental stages even in the United States. With the live transmission of the Tokyo Olympic Games across the Pacific by the American Satellite ‘Syncom-3’ demonstrating the power of communication satellites, Dr. Vikram Sarabhai, the founding father of the Indian space programme, quickly recognized the benefits of space technologies for India.

As a first step, the Department of Atomic Energy formed the INCOSPAR (Indian National Committee for Space Research) under the leadership of Dr. Sarabhai and Dr. Ramanathan in 1962. The Indian Space Research Organisation (ISRO) was later formed on August 15, 1969. It is one of the six largest space agencies in the world. The Department of Space (DOS) and the Space Commission were set up in 1972 and ISRO was brought under DOS on June 1, 1972.

The Indian space programme has been orchestrated well and had three distinct elements such as, satellites for communication and remote sensing, the space transportation system, and application programmes. Two major operational systems have been established – the Indian National Satellite (INSAT) for telecommunication, television broadcasting, and meteorological services and the Indian Remote Sensing Satellite (IRS) for monitoring and management of natural resources, and Disaster Management Support.

1. Indian Space Programme began at Thumba Equatorial Rocket Launching Station (TERLS) located at Thumba near Thiruvananthapuram. Thumba was selected for being a rocket launching station because the geomagnetic equator of the earth passes over Thumba. The geomagnetic equator of the earth passes over Thumba.
2. On November 21, 1963, the first sounding rocket was launched from TERLS. The first rocket, a Nike Apache was procured from the US. A sounding rocket is a rocket, which is intended for assessing the physical parameters of the upper atmosphere.
3. The Satellite Telecommunication Earth Station was set up at Ahmedabad on January 1, 1967.
4. India’s first indigenous-sounding rocket, RH-75, was launched on November 20, 1967.
5. Aryabhata – First Indian Satellite was launched on April 19, 1975. It was launched from the former Soviet Union. It provided India with the basis of learning satellite technology and designing.
6. During 1975-76, ISRO along with NASA developed means of using space communications systems for TV broadcasting. This resulted in the creation of the project Satellite Instructional Television Experiment (SITE). It was a one-year program covering Indian villages and districts. The main purpose of SITE was to experiment usage of satellite broadcasting to educate the masses. SITE, hailed as ‘the largest sociological experiment in the world’ benefited around 200,000 people, covering 2400 villages of six states and transmitted development-oriented programmes using the American Technology Satellite (ATS-6).
7. From January 1, 1977 — January 1, 1979, the Satellite Telecommunication Experiments Project (STEP), a joint project of ISRO and Post and Telegraphs Department (P&T) using the Franco-German Symphonie satellite was taken up. Conceived as a sequel to SITE which focused on Television, STEP was for telecommunication experiments.
8. Bhaskara-I – an experimental satellite for earth observations was launched on June 7, 1979.
9. First Experimental launch of SLV-3 with Rohini Technology Payload on board (August 10, 1979). The satellite could not be placed in orbit. Satellite Launch Vehicle-3 (SLV-3) is the first launch vehicle of India.
10. Ariane Passenger Payload Experiment (APPLE), an experimental geostationary communication satellite was successfully launched on June 19, 1981. It became the forerunner for future communication satellite systems.
11. Indian National Satellite System (INSAT)-1A was launched on April 10, 1982. This system was for communication, broadcasting, and meteorology.
12. On April 2, 1984, the first Indo-Soviet manned space mission was launched. Rakesh Sharma became the first Indian citizen to go into space. He flew aboard in the Soviet rocket Soyuz T-11, as part of a three-member Soviet-Indian crew.
13. The launch of the first operational Indian Remote Sensing Satellite, IRS-1A happened on March 17, 1988.
14. The second developmental launch of the Polar Satellite Launch Vehicle (PSLV) with IRS-P2, on board took place on October 15, 1994. The satellite was successfully placed in Polar Sun-synchronous Orbit. PSLV went on to become a favoured carrier for satellites of various countries due to its reliability and cost efficiency, promoting unprecedented international collaboration.
15. The first developmental launch of Geosynchronous Satellite Launch Vehicle (GSLV)-D1 with GSAT-1 on board took off from Sriharikota on April 18, 2001. It was developed keeping in mind the heavier and more demanding Geosynchronous communication satellites.
16. PSLV-C11 successfully launches CHANDRAYAAN-1 from Sriharikota on October 22, 2008. Chandrayaan-1 is a scientific investigation – by spacecraft – of the Moon. The name Chandrayaan means “Chandra- Moon, Yaan-vehicle”, –in Indian languages (Sanskrit and Hindi) , – the lunar spacecraft. Chandrayaan-1 is the first Indian planetary science and exploration mission. Chandrayaan-1 was operational for 312 days till August 28, 2009.
17. November 5, 2013 – PSLV – C25 successfully launches Mars Orbiter Mission (Mangalyaan) Spacecraft from Sriharikota.
18. On February 15, 2017, PSLV-C37, the 39th mission of the workhorse launch vehicle of ISRO, injected ISRO’s Cartosat-2 Series Satellite weighing 714 kg and two ISRO Nano-satellites namely INS-1A (8.4 kg) & INS-1B (9.7 kg) and 101 Nano-satellites, from six foreign countries into a Sun-Synchronous Orbit (SSO) at an orbit of 506 km above earth, with an inclination of 97.46°. The mass of nano-satellites varied from 1 to 10 kg. The total weight of all the 104 satellites carried onboard PSLV-C37 was 1378 kg.
19. PSLV-C38/Cartosat-2 Series Satellite Mission was launched on June 23, 2017, from SDSC SHAR, Sriharikota.India’s Polar Satellite Launch Vehicle, in its 40th flight (PSLV-C38), launched the 712 kg Cartosat-2 series satellite for earth observation and 30 co-passenger satellites together weighing about 243 kg at lift-off into a 505 km polar Sun Synchronous Orbit (SSO).
20. India’s latest communication satellite, GSAT-17 was inducted into the INSAT/GSAT system on June 29, 2017, from Kourou, French Guiana by Ariane-5 VA-238. Weighing 3477 kg at lift-off, GSAT-17 carries Payloads in Normal C-band, Extended C-band and S-band to provide various communication services. GSAT-17 also carries equipment for meteorological data relay and satellite-based search and rescue services being provided by earlier INSAT satellites.
21. India’s Polar Satellite Launch Vehicle, in its forty-second flight (PSLV-C40), successfully launched the 710 kg Cartosat-2 Series Satellite for earth observation and 30 co-passenger satellites together weighing about 613 kg at lift-off. PSLV-C40/Cartosat-2 Series Satellite Mission was launched on Friday, Jan 12, 2018.
22. GSLV-F08 is the 12th flight of a Geosynchronous Satellite Launch Vehicle (GSLV) and the Sixth flight with an indigenous Cryogenic Stage. GSLV -F08 / GSAT-6A Mission was launched on Thursday, March 29, 2018.
23. India’s Polar Satellite Launch Vehicle, in its forty-third flight (PSLV-C41) in XL configuration launched IRNSS-1I Satellite. The ‘XL’ configuration of PSLV is used for the twentieth time. The IRNSS-1I is the eighth satellite to join the NavIC navigation satellite constellation and was launched on April 12, 2018.
24. PSLV-C42 Successfully Launches two foreign satellites from Satish Dhawan Space Centre (SDSC), SHAR, Sriharikota on September 16, 2018. This mission was designed to launch two earth observation satellites, NovaSAR and S1-4 (together weighing nearly 889 kg).
25. PSLV-C43 lifted off on November 29, 2018, from the First Launch Pad (FLP) of Satish Dhawan Space Centre SHAR, Sriharikota, and successfully launched India’s Hyperspectral Imaging Satellite (HysIS) and 30 international co-passenger satellites.
26. India’s next-generation high throughput communication satellite, GSAT-11 was successfully launched on December 05, 2018, from the Kourou launch base, French Guiana by Ariane-5 VA-246. Weighing about 5854 kg, GSAT-11 is the heaviest satellite built by ISRO.
27. GSLV-F11 successfully launched GSAT-7A, ISRO’s 39th communication satellite, on December 19, 2018, from Satish Dhawan Space Centre SHAR, Sriharikota. GSLV-F11 is the 13th flight of India’s Geosynchronous Satellite Launch Vehicle (GSLV) and its 7th flight with indigenous Cryogenic Upper Stage (CUS). GSLV–F11 is ISRO’s fourth-generation launch vehicle with three stages. It is a geostationary satellite carrying communication transponders in the Ku band. The Satellite is built to provide communication capability to users over the Indian region.
28. Gaganyaan Programme – Cabinet has approved Indian Human Spaceflight Initiative – Gaganyaan Programme. Two unmanned & one manned flight have been planned. Estimates for Phase-I expenditure- Rs 9023 Crores. Gaganyaan Programme will establish a broader framework for collaboration between ISRO, academia, industry, national agencies, and other scientific organizations.
29. India’s telecommunication satellite, GSAT-31 was successfully launched on February 06, 2019, from the Kourou launch base, French Guiana by Ariane-5 VA-247.
30. India’s PSLV-C46 successfully launched the RISAT-2B satellite from Satish Dhawan Space Centre (SDSC) SHAR, Sriharikota on May 22, 2019. The satellite is intended to provide services to Agriculture, Forestry, and Disaster Management domains.
31. Geosynchronous Satellite Launch Vehicle, GSLV MkIII-M1 rocket, carrying Chandrayaan-2 spacecraft was launched from the Satish Dhawan Space Centre, Sriharikota in Andhra Pradesh on July 22, 2019. Chandrayaan-2 is India’s second mission to the moon. It comprises a fully indigenous Orbiter, Lander (Vikram), and Rover (Pragyan). The Rover Pragyan is housed inside Vikram Lander. Chandrayaan-2 has several science payloads to facilitate a more detailed understanding of the origin and evolution of the Moon. To know more about Chandrayan 2.
32. India’s PSLV-C47 successfully launched Cartosat-3 and 13 commercial nanosatellites from Satish Dhawan Space Centre (SDSC) SHAR, Sriharikota on November 27, 2019.
33. India’s Polar Satellite Launch Vehicle, in its fiftieth flight (PSLV-C48), successfully launched RISAT-2BR1, an earth observation satellite, along with nine commercial satellites of Israel, Italy, Japan and the USA from Satish Dhawan Space Centre (SDSC) SHAR, Sriharikota on December 11, 2019.
34. India’s Polar Satellite Launch Vehicle PSLV-C51 successfully launched Amazonia-1 along with 18 co-passenger satellites on February 28, 2021,
35. ISRO undertakes PSLV-C53/DS-EO mission on June 30, 2022. PSLV-C53 is the second dedicated commercial mission of New Space India Limited (NSIL).

Chandrayaan-2,  XPoSat (to study cosmic radiation in 2020), and Aditya-L1(to the Sun in 2021).

Undefined Missions – which include missions that are still in the planning stage namely Mangalyaan-2 (or Mars Orbiter Mission-2 in 2022), Lunar Polar Exploration (or Chandrayaan-3 in 2024), Venus mission (in 2023), Exoworlds (exploration outside the solar system in 2028).

Frequently Asked Questions (FAQs)

Q: What is the significance of space technology in the modern world?

A: Space technology plays a crucial role in various aspects of modern life. It facilitates communication, weather monitoring, navigation, and scientific exploration. Satellites enable global connectivity, enhance disaster management, and contribute to national security. Additionally, space technology fosters international cooperation and promotes advancements in science and technology.

Q: How does India contribute to space exploration and technology?

A: India has made significant strides in space exploration through organizations like the Indian Space Research Organisation (ISRO). Notable achievements include the successful Mars Orbiter Mission (Mangalyaan) and the Chandrayaan missions to the Moon. ISRO has also developed a cost-effective launch vehicle, the Polar Satellite Launch Vehicle (PSLV), making India a reliable player in the global space industry. The country continues to invest in space technology for socio-economic development.

Q: What challenges does space technology face in the 21st century?

A: The 21st century poses both opportunities and challenges for space technology. Challenges include space debris management, cybersecurity threats to satellites, and the need for sustainable space exploration. International collaboration becomes essential to address these challenges. Additionally, ensuring responsible use of space technology and preventing its weaponization are critical aspects that require global cooperation and adherence to ethical guidelines.

In case you still have your doubts, contact us on 9811333901. 

For UPSC Prelims Resources, Click here

For Daily Updates and Study Material:

Join our Telegram Channel – Edukemy for IAS

• 1. Learn through Videos – here
• 2. Be Exam Ready by Practicing Daily MCQs – here
• 3. Daily Newsletter – Get all your Current Affairs Covered – here
• 4. Mains Answer Writing Practice – here

Visit our YouTube Channel – here