Nuclear Energy in India

Nuclear Energy in India

This article deals with ‘Nuclear Energy in India.’ This is part of our series on ‘Science and Technology’ which is an important pillar of the GS-3 syllabus. For more articles, you can click here

Installed capacity of Nuclear Power in India

India has been actively pursuing nuclear power as a part of its energy mix to meet its growing electricity demands and reduce its dependence on fossil fuels.

Nuclear Energy in India

Nuclear Plants in India

Nuclear Plants in India

Problems with India’s Nuclear Power

India’s domestic Uranium Reserve can support only 100 GW of energy. 

  • Our future depends upon the development of the third stage of the Nuclear Program, without which it will remain dependent on imported Uranium, as it is the case with Oil currently.

High Cost

  • Increased Cost due to New Safety Regulations: Due to new safety regulations following the Fukushima tragedy, nuclear reactors now cost substantially more per MW than thermal, solar, and wind plants. E.g., the Jaitapur plant (AREVA) is expected to cost 20 crore/ MW in comparison other sources cost 4 crore/ MW. 
  • Some argue that the Total costs of a Nuclear Lifecycle, which involves the mining of Uranium, transportation, handling of waste generated etc., is significantly more than the economic value generated during the lifetime of the functioning of the plant

Alternative Energy Options

  • Experts opine that India should focus on renewable energy like solar and wind, which are considered safer, environmentally friendly, and have rapidly declining costs. Investing in renewables can also help address energy access issues in rural areas and reduce dependence on fossil fuels.

Public Opposition and Social Concerns

  • Nuclear power projects often face opposition from local communities and environmental groups due to concerns about radiation risks, potential accidents, and the long-term impact on public health and the environment.

Current Nuclear reactors consume a significant amount of water

  • Hence most of upcoming plants will be set up near sea coasts. It will put pressure on the coastline & Western Ghats. 

Long Gestation Period

  • There are long gestation periods which increase the costs of the plant significantly.

Non-proliferation and international obligations

  • India hasn’t signed the NPT and has faced scrutiny regarding its nuclear weapons program.

Target of Terrorists

  • Nuclear installations will be the favourite targets of terrorists, which can cause irreversible damage to people. 

Should Nuclear Energy be used?

Strong arguments which justify the use of nuclear energy are 

  1. No GHG are emitted in Nuclear Power generation, a significant contributor to climate change. Hence, it helps to fight Global Warming
  2. Nuclear Energy is helpful in achieving Paris Pledge. India has also pledged to generate 40% of its energy from Non-fossil sources.
  3. Energy security and independence: Nuclear energy reduces dependence on imported fossil fuels, enhancing energy security for countries. 
  4. Job creation and economic benefits: Nuclear power plants require skilled workers for operation, maintenance, and construction, thus creating employment opportunities. 
  5. Increases the image of the country as a technologically advanced nation
  6. Non-fluctuating sources of renewable energy as Solar and wind energy, depend on sunshine, wind speed etc. On the other hand, Nuclear power plants provide a continuous and reliable source of electricity.
  7. Baseload power and grid stability: Nuclear power provides a stable and consistent baseload power supply, essential for maintaining grid stability. It can complement intermittent renewable energy sources,
  8. It generates very limited waste in quantity (although far more hazardous in quality). 

Arguments against use of Nuclear Energy

While there are strong arguments in favour of nuclear energy, there are also valid concerns regarding high cost, waste disposal, potential accidents, the proliferation of nuclear weapons, and the high cost of building and decommissioning nuclear plants. 

  1. Costs of power from new nuclear reactors are increasing significantly post Fukushima Disaster. New PHWR power costs between Rs. 6.2-6.5/Unit  
  2. In case of any nuclear leakage & accident in nuclear power plants, the damage is immense & incurable. 
  3. Nuclear projects face opposition from local communities and environmental groups due to land acquisition issues, the need for large water reservoirs for the reactors, & concerns about a possible tsunami scenario 
  4. Major Nuclear Companies like Toshiba-owned Westinghouse, Areva etc., are on the verge of Bankruptcy, pointing towards the fact that Nuclear Energy has become unviable.
  5. Investing in Solar and Wind Energy is a better option. The cost of Solar Energy has decreased to around ₹4.5 / kWh compared to ₹6.5 kWh of Nuclear Energy. 
  6. Uranium contamination of groundwater due to mining. E.g.,: in Rajasthan

Anti-Microbial Resistance

Anti-Microbial Resistance

This article deals with ‘Anti-Microbial Resistance – for UPSC.’ This is part of our series on ‘Society’, which is an important pillar of the GS-1 syllabus. For more articles, you can click here.

What is Anti-Microbial Resistance?

Anti-Microbial Resistance (aka Antibiotic Resistance) happens when microorganisms (such as bacteria, parasites, viruses and fungi) evolve when they are exposed to the antibiotic and develop resistance mechanisms to it or acquire that resistance from another bacterium. 

Anti-Microbial Resistance


2010 It became a topic of debate in India when the British journal Lancet named an enzyme as New Delhi Metallo-beta-lactamase-1 or NDM-1, which had antimicrobial resistance  
2016 Resistance to Colistin was detected in China. Colistin is the last resort of antibiotics.   
Sept 2016 United Nations held a high-level meeting to tackle Antimicrobial Resistance.  

Note: It was only the fourth time the general assembly held a high-level meeting for a health issue (previously, it was for HIV non-communicable diseases such as heart disease and diabetes and Ebola).
2017 A US woman died from an infection that was resistant to all 26 available antibiotics. 
2023 Muscat Conference on Antimicrobial Resistance held.  Muscat Manifesto was released, calling for
1. Accelerating the political commitments in the implementation of One Health Action
2. Recognize the impact of AMR on humans as well as Animals. 

Causes of Anti-Microbial Resistance

Causes of Anti-Microbial Resistance

Significant sources of resistance: 

  • Overuse of antibiotics by human beings  (over prescription)
  • Self-medication
  • Overuse of antibiotics in the veterinary sector
  • Environmental antibiotic contamination due to pharmaceutical companies and hospital discharge. 
  • Lack of new antibiotics being developed
  • Patients not finishing treatment 
  • Poor infection control in hospitals 

Ways to control Anti-Microbial Resistance


Prescriber should 

  • Follow guidelines
  • Perform Antimicrobial susceptibility tests
  • Maintain hygiene, disinfection and sterilization in the hospital


Farmers should

  • Follow guidelines.
  • Use only animal-specific antibiotics
  • Maintain hygiene


Public should 

  • Follow the prescription and don’t self-medicate himself
  • Public awareness and education should be carried out 


Politician should

  • Establish Antibiotic Resistance related laws
  • Make National Plans and Guidelines 
  • Invigorate the antibiotic development of pharmaceutical companies


Researcher should 

  • Develop a new generation of antibiotics 
  • Develop Molecular Techniques for identifying resistance genes.

Initiatives taken by Government 

1. Red Line Campaign

Red Line Campaign for Anti Microbial Resistance

2. National Surveillance System for Anti-Microbial Resistance 

  • The program keeps a close watch on such cases.

3. National Action Plan on Anti-Microbial Resistance

  • The program was started April 2017  
  • It focused on
    1. Hand Hygiene and Sanitation programs
    2. One Health Strategy

4. National Health Policy, 2017

  • It had specific guidelines for the use of antibiotics and limiting the use of antibiotics.

5. Schedule H1 of Drugs and Cosmetic Rule, 1945

Schedule H1 was added to the Drugs and Cosmetic Rule 1945. Drugs in Schedule H1 are required to be sold in the country with the following conditions:-

  1. Their sale has to be registered in the register with the name of the prescriber and patient  
  2. Drugs shall be labelled with the symbol Rx & drug warning.   

International Steps

1. By WHO

  • WHO is providing technical assistance to countries to develop national action plans to combat Antimicrobial Resistance and strengthen their surveillance systems. 
  • One Health Approach: The One Health approach recognizes the interconnectedness between human, animal, and their shared environment. It emphasizes the importance of addressing health issues comprehensively by considering the interdependencies and interactions between humans, animals, and their shared environments. The ‘One Health’ approach calls for optimal antibiotic use in both humans and animals.

2. UNO

  • A high-level meeting on antimicrobial resistance was held at the United Nations General Assembly.  

3. New Antibiotics 

  • For example, ODLs are a new class of antibiotics discovered by the University of Illinois and Nosopharm, a French company.

Indian Healthcare Sector

Indian Healthcare Sector

Indian Healthcare Sector

This article deals with ‘Indian Healthcare Sector  – for UPSC.’ This is part of our series on ‘Society’, which is an important pillar of the GS-1 syllabus. For more articles, you can click here.

Healthcare Data

Healthcare Expenditure

Healthcare Expenditure in India

Global Burden of Disease Report (2018) by LANCET

Global Burden of Disease Report (2018) by LANCET

Other Relevant Data

Doctor-Population Ratio 1:834 (against the WHO norm of 1:1000)
Number of Hospital Beds per 1000 0.7 (against the WHO norm of 3.5)

Political & Constitutional Angle

  • Health is under the State List. But there is debate regarding whether it should be moved to the Concurrent List, given that even after 70 years of independence, the state of Health in India is still poor. The Centre can only make model laws to which states can voluntarily subscribe.
  • Article 47 of the Indian Constitution (Directive Principle of State Policy) speaks about raising its people’s nutrition levels and living standards and improving public health as among its primary duties.
  • Article 21, i.e. Right to Life is Fundamental Right under the Indian Constitution.

Health and SDG

Sustainable Development Goals also talks about Health and SDG-3 aims to ensure healthy lives and promote well being for all at all ages.

Health and SDG

Primary, Secondary and Tertiary Healthcare

Primary Healthcare

  • Primary Healthcare is the first level of contact between people & health system
  • It includes family planning, immunization, treatment of common diseases, health education etc. 
  • In India, it is provided through a network of 
    • Primary Health Centres in Rural Areas
    • Family Welfare Centres in Urban Areas

Secondary Healthcare

  • Secondary Healthcare denotes the second Tier of the health system.
  • It includes 
    • District Hospitals 
    • Community Health Centre (CHC) at Block Level

Tertiary Healthcare

  • Tertiary Healthcare denotes the third tier of the health system.
  • It provides specialized consultative care.          
  • Tertiary Healthcare is provided through Medical Colleges & Medical Research Institutes. 

Rural Healthcare System

Indian Healthcare Sector

State of Health Services in India

Health services in India need a booster shot, vouched by the following data. 

  • Prominence of Private Sector: According to Economic Survey, out of 4% of expenditure on Healthcare in India, Public Sector accounts for just 1.15% 
  • High Out-of-Pocket Expenditure (OoPE): The OoPE in India is as high as 62% compared to the world average of 18%. High OoPE pushes 39 million people every year under the poverty line. 
  • Indian Doctors are not willing to serve in Rural Areas due to various factors, such as a lack of adequate healthcare infrastructure and low opportunity for professional growth.
  • The dominance of the Medical Council of India has hindered the development of nurses and other health cadres.
  • Hesitancy/Ignorance of common people: Even after a person has TB symptoms, they delay visiting a doctor (for a minimum of 5.2 months, even in Delhi). As a result, their disease becomes worse, and they infect more people. 

With the implementation of the Ayushman Bharat program, the strengthening of SCs and PHCs is being done by converting them into Health and Wellness Centres (HWCs) in a phased manner to deliver comprehensive Primary Healthcare services through these Centres. 

Health Schemes

1. National Health Mission

  • National Health Mission (NHM) is a flagship program of the Indian Government that aims to provide affordable, accessible, affordable, and quality healthcare to all citizens.   
  • It is Core Scheme (60:40 Division) 
National Rural Health Mission (NRHM) In areas having a population below 50,000
National Urban Health Mission (NUHM) In areas having a population above 50,000

2. Pradhan Mantri  Bhartiya Jan Aushadhi Pariyojana (PMBJP)

  • The scheme aims to provide affordable generic medicines to the masses to reduce out-of-pocket expenses. These are made available through Jan Aushadhi Stores. 

3. Rogi Kalyan Samiti

  • Rogi Kalyan Samiti is a registered society consisting of citizens of the area who act as trustees to manage hospital functions.
  • It acts as a check and increases the accountability of doctors.

4. Universal Immunization Program (UIP)

Under Indian Immunisation Program, Vaccine is given for 12 life-threatening diseases

National (11 Diseases) 1. Diphtheria
2. Pertussis (Whooping Cough)
3. Tetanus (DPT)
4. Polio
5. TB
6. Rotavirus Diarrhoea
7. Hepatitis B
8. Meningitis & Pneumonia caused by Haemophilus Influenza Type-B
9. Measles
10. Rubella
11. Pneumococcal Pneumonia (latest entry in 2021, earlier it was given in select districts of Himachal and Bihar)
Sub-National (1 Disease) 12. Japanese Encephalitis

5. Menstruation Health

Government is running following schemes for Menstruation Health.

  • Menstrual Hygiene for Adolescent Girls Scheme: To address the need for menstrual hygiene among adolescent girls residing in rural areas. 
  • Project Stree Swabhiman (by Ministry of Electronics and Information Technology)
  • Menstrual Hygiene Scheme  (by Health Ministry as part of Rashtriya Kishor Swasthya Karyakram. )
  • Rashtriya Madhyamik Shiksha Abhiyan (by Ministry of Human Resource Development)

6. Drug Price Control Order

  • The Drug Price Control Order (DPCO) of India is a regulatory framework established by the government to control and regulate the prices of essential medicines in the country.
  • Schedule 1 of DPCO contains the List of Essential Medicines. Their price can’t be more than the ceiling price.  

Public Health Policy, 2017

The previous policy was formulated in 2002. There was a need for a new policy because 

  • 15 years have passed, and new challenges have come up in the health sector. 
  • At that time, Polio was a major problem. Now, WHO has declared India to be Polio Free.
  • That policy was keeping in view of Millennium Development Goals (MDG). Now, we are in the era of Sustainable Development Goals (SDG).  
  • At that time, Communicable Diseases were a major problem. Now Non-Communicable Diseases have come into the scene.

Provisions of the National Health Policy, 2017

1. Finance 

  • Presently, the government spends 1.15 % of GDP on healthcare. The target is to increase that to 2.5% of GDP by 2025.  

2. Targets to be achieved

  • Increase the life expectancy from 67.5 to 70 by 2025.
  • Reduce premature mortality from Non-Communicable Diseases by 25 per cent by 2025.
  • Achieve the global 2020 HIV target (also termed 90:90:90)

3. Preventive and Curative Care

  • The policy will rely on Preventive as well as Curative Health Care (the 2002 Policy relied just on curative )

4. Focus on Primary Care 

  • Policy advocates allocating two-thirds (or more) of resources to primary care.  

5. Promote AYUSH 

  • AYUSH will be promoted 

6. Promote Make in India

  • Promote drugs and devices manufactured in the country.


  • The policy has abandoned the idea of making health a right proposed under the Draft Health Policy. NHP (2017) speaks of an “assurance-based approach”.
  • Raising Government Expenditure to 2.5% of GDP till 2025 is too far-fetched given problem India is facing is serious. Along with that, no year wise plan of yearly incrementation is given. There is lesser hope that even this will be attained given the past experience that the health policy of 2002 had promised health expenditure of 2% of its GDP on Health by 2010
  • Governance issues are ignored: The policy is silent on whether health should be moved to the Concurrent list.
  • Professional issues are ignored, e.g., MCI issues and private practice by Govt doctors.

Nuclear Fission Reactors

Nuclear Fission Reactors

This article deals with ‘Nuclear Fission Reactors .’ This is part of our series on ‘Science and Technology’ which is important pillar of GS-3 syllabus . For more articles , you can click here.

Nuclear Fission

  • In 1939, Otto Hahn and Strassman discovered Nuclear Fission when they found that a slow-moving neutron collides with a uranium nucleus; it breaks into two smaller nuclei of comparable masses with the release of energy. 
  • In simple words, Nuclear Fission means breaking up the heavier nucleus into two smaller nuclei and releasing an enormous amount of energy.
Nuclear Fission Reaction
  • Reactant total mass is more than product total mass & EXCESS mass is converted to energy (using Einstein’s Mass – Energy Relation (E = mc^2)). The energy released from 1 nucleus of Uranium (235) is nearly 93 Mega Electron Volt. When one Uranium nucleus undergoes fission, the energy released might be small. But from each fission reaction, three neutrons are released. These three neutrons can cause further fission in three other Uranium nuclei. This process is called a chain reaction.
  • The energy produced in the nuclear reaction can be used to convert water into steam, which can be converted into electricity using Steam Turbine and Generator.

Types of Reactors

A simple Nuclear Reactor from which electricity can be generated is of following type

Types of Reactors
Fuel U-235, U-233, Pu – 239 or Th -232 is used as fuel in the Nuclear Reactor  
Moderator It reduces the speed of neutrons so that nuclear reactions can take place. 
– Graphite or Heavy Water (D2O) is used as Moderator.  
Coolant The coolant absorbs the energy/heat released from the reaction and transfers it into turbines.
Heavy Water or Water can be used as coolant (depending on the type of Reactor)  
Control Rods To control the speed of the Nuclear Reactor.
Boron or Cadmium is used as Control Rod.  
Concrete Shield Concrete wall with 2-5 m thickness to stop radiation from spreading.

Reactors used in India

1. Pressurized Heavy Water Reactor (PHWR)

Most of the Nuclear Reactors found in India are PHWRs.

Information at Glance

Fuel Natural Uranium (without enrichment) (It is easier to make and less expensive to use, as Uranium enrichment is a complex process)
Coolant Heavy Water/Deuterium Oxide
By Products Plutonium  (more amount )
Moderator Heavy Water/Deuterium Oxide (Moderator and coolant are same) => Neutrons collide with Heavy Water molecules and slow them.  
Why Pressurized If water is heated, it expands & becomes less dense. As a result probability of collision between neutrons and water molecules to reduce the speed of neutrons decreases. It is crucial to decrease the speed of neutrons to ensure fission.
Cost Less Expensive
Pressurized Heavy Water Reactor (PHWR)

Details of PHWRs

The primary reaction which leads to the generation of energy while using Uranium as fuel is

Nuclear Fission Reaction
  • The most crucial point in Uranium Fission Reaction is the release of an extra 2.5 (average) Neutrons, which leads to the possibility of a chain reaction. If controlled, it can be used to produce energy called Nuclear Energy. At the same time, if it remains uncontrolled, it can result in an Atomic Bomb.
  • But the biggest hurdle, in this case, is the fact that neutrons liberated in the nuclear reaction are fast-moving & will not cause fission (instead, they will escape without causing any collision). To ensure a Fission reaction, these neutrons must be slowed. For this purpose, Moderators are used, which in this case are D2O (Heavy Water) & Graphite.
  • The reaction rate can be controlled by Control Rods, which are made up of neutron-absorbing material like Cadmium
  • The energy released in fission is continuously removed by a suitable Coolant which transfers heat to a working fluid which in turn may produce steam to drive the turbine & generate electricity. 
  • Pressuriser is used because when heavy water is heated, it expands & becomes less dense. As a result probability of collision between neutrons and heavy water molecules to reduce the speed of neutrons decreases. It is crucial to decrease the speed of neutrons to ensure fission. The Pressuriser ensures the suitable density of the heavy water.

2. Boiling Water Reactor (BWR)

  • It is the oldest type of Nuclear Reactor.
  • Fuel Used: Enriched Uranium
  • Working: Energy released during the fission reaction directly heats the (light) water. The same water is used to turn the turbine and then recycled back, to be used again in the cycle.
  • Moderator: No Moderator is used. The probability of neutron colliding with U-235 is achieved by using Enriched Uranium.
Boiling Water Reactor (BWR)
  • BWRs are the second most widely used reactors in the world. But in India, we don’t use them on a large scale. Tarapur Atomic Power Station was constructed initially with two boiling water reactors (BWR) under the 1963 Agreement between India, USA & International Atomic Energy Agency (IAEA).

Issue with BWR

  • The use of enriched Uranium increases cost and complexities.
  • Light water is directly heated by radioactive material. Hence, nuclear radiation fallout in case of an accident is maximum in such reactors. For example, Japan’s Fukushima Nuclear reactor, which caused great damage after a nuclear accident, was BWR. 

3. Fast Breeder Reactor

  • Fast Breeder Reactor produces the same kind of fissile material as it burns.
  • While using Pu239 as fuel, it can produce more Pu239 than it consumes by converting non-fissionable U-238 present in the natural Uranium.
  • With fast neutrons, the chances of absorption by U-238 increase. Additionally, Pu-239 produces extra neutrons in the case of a collision with fast-moving neutrons only. Hence, these reactors don’t use moderators to slow down the neutrons.
  • Liquid sodium or steam coolants are used in FBRs. 
  • India’s BHAVINI nuclear reactor is Prototype Fast Breeder Reactor.
Fast Breeder Reactor

Prelims Related: List of BARC Atomic Reactors

Apsara First Atomic Reactor in 1957  
Cirus Indo-Canadian Reactor
Operational Period: 1960-2010
Zerlina Operationalized in 1961
To study Uranium Heavy Water Reactors
Dhruva Operationalized in 1984
Completely indigenous reactor
Purnima -1  
Kamini – India’s first Fast Breeder Reactor.
Installed in Kalpakkam
India is 7th country in world to have FBR

Indian Three Stage Nuclear Program

Indian Three Stage Nuclear Program

This article deals with ‘Indian Three Stage Nuclear Program.’ This is part of our series on ‘Science and Technology’ which is an important pillar of the GS-3 syllabus. For more articles, you can click here


Indian Three Stage Nuclear Program
  • Homi Bhabha formulated India’s 3-Stage Nuclear Program. 
  • The reason for the formulation of this program was that India has the largest source of Thorium and modest deposits of Uranium. Considering this fact, Dr Homi Bhabha envisioned 3-Stage Nuclear Program in 1954. It aimed to secure India’s long-term energy independence by using Uranium and Thorium reserves found in the Monazite sands of coastal India. 
  • Note: India has only 1-2% of the global Uranium but about 30% of the world’s Thorium.

Stage 1

The first stage involves the utilization of Pressurized Heavy Water Reactors (PHWR) fuelled by natural Uranium. In this stage, natural Uranium is used as a fuel, and heavy water (deuterium oxide) is used as a moderator and coolant. India has built several PHWRs, which generate electricity and produce plutonium-239 as a by-product (to be used as fuel for the next stage.)



  • Pressurized Heavy Water Reactor (PHWR)

Fuel used

  • Natural Uranium (Note: It is not enriched. Just Natural Uranium is used.)

Moderator and coolant

  • Heavy Water (D2O/Deuterium Oxide)


Main Reaction (Energy)

Stage 1 of Nuclear Energy: Reaction 1

Other  (to get Pu -239)

Stage 1 of Nuclear Energy: Reaction 2

Process explained

  • Natural Uranium contains both U-238 and U-235 in the following proportions.
Natural Uranium - composition
  • In Nuclear Reactor, when a slow-moving Neutron is bombarded on the Uranium fuel, it collides with and splits U-235 nuclei, thus releasing a large amount of energy and 3 neutrons. The production of 3 neutrons helps in making it a chain reaction. 
  • Some of the neutrons will get absorbed into U-238, thus converting it into Pu-238 (Plutonium-238, which is fissile). Pu-238, thus generated, acts as fuel in the second stage.

Pressurized Heavy Water Reactor

Pressurized Heavy Water Reactor

Why is Heavy Water is used as Moderator?

  • A moderator in the form of Heavy Water is used to decrease the speed of neutrons produced in the nuclear reaction because it increases the probability of fission with Uranium-235, even though its proportion is just 0.7% in natural Uranium. 
  • Heavy water slows down neutrons by their repeated collisions with neutrons.

Control Rods

  • To reduce the power level or to shut down the reactor, the reaction rate is lowered by decreasing the number of available neutrons. It is achieved with the help of control rods like Boron or Cadmium Rods, which can absorb the neutrons.

The operator of PHWR or First Stage of the Indian Nuclear Program 

  • PHWR is operated by NPCIL or Nuclear Power Corporation of India Limited. 
  • Almost the entire base of Indian nuclear power is composed of stage 1 PHWRS except for the two Boiling Water Reactors (BWRs) at Tarapore.

Stage 2

Fast Breeder Reactor

Stage 2 of Indian Three Stage Nuclear Program


The second stage focuses on utilizing Fast Breeder Reactors. FBRs use Plutonium-239 obtained from the spent fuel of PHWRs as the fuel and liquid sodium as the coolant. These reactors can generate more fissile material (Plutonium-239) than they consume. Thorium would be added to the fuel cycle once sufficient stock had been amassed to transform it into uranium 233 for the third stage.


  • FBR (Fast Breeder Reactor )

Fuel used

Mixed oxide (MOX) fuel (received from first stage) consisting of

Pu-239 Undergo fission to produce more energy
U-238 Undergo change to additional Pu239


  • FBR doesn’t use a Moderator, as only fast-moving neutrons produce extra neutrons on collision with Pu-239.


  • Liquid Sodium 

Crucialties of Stage 2

Further, 2nd stage is crucial for 3rd stage as it converts Thorium-232 (which occurs naturally) into Uranium–233 by transmutation

  • Once there is a good reserve of Pu-239, Th-232 is introduced at the periphery of the core (blanket material).
  • The collision with neutrons will convert Th-232 to U-233 (which is fissile).

Stage 3

Thorium Based Reactors

Stage 3 of Indian 3 Stage Nuclear Programme

The program’s third and final stage involves deploying Advanced Heavy Water Reactors. AHWRs are designed to use a mix of Thorium-232 and Uranium-233 (obtained as a by-product from 2nd stage) as fuel. Additionally, The Th-232 will be placed at the periphery of the Core fuel, resulting in additional U-233 fuel.

It’s important to note that while India has made significant progress in the first two stages, the third stage of the program is still in the developmental phase, and commercial deployment of AHWRs is yet to take place.

Thorium as Nuclear Fuel

India & Thorium

  • India has the largest reserve of Thorium in the world and consists of 30% of the world’s Uranium reserves
  • Main Indian reserves include 
    • Monazite beach sand in Kerala 
    • Found in Andhra (largest producer), Tamil Nadu, Odisha, Kerala and West Bengal


  • Thorium is more abundant (4 times more) than Uranium in the Earth’s crust. 
  • Thorium consists of a single isotope, Th-232, unlike Uranium. Hence there is no need for the isotope separation. 
  • Thorium-based fuels have favourable physical and Chemical properties that improve the reactor’s performance. These include
    • Higher melting point 
    • Higher thermal conductivity 
    • Low coefficient of thermal expansion 
    • Greater chemical stability 
    • Doesn’t further oxidise 
  • The long-term radiological hazard of Uranium based nuclear fuel, dominated by Plutonium and other Actinides is not there in Thorium based fuel. 


  • No fissile isotopes in natural Thorium
  • The high sintering temperature required to make Thorium Oxide 
  • Long interval over which Thorium 232 breeds to Uranium 233 



This article deals with ‘Cloning – UPSC.’ This is part of our series on ‘Science and Technology’, an important pillar of the GS-3 syllabus. For more articles, you can click here.

What is Clone?

  • A clone is either an organism or a cell produced asexually from an ancestor.
  • A cloned cell is genetically & physically identical to its ancestor.
  • British biologist JBD Haldane in 1963, theorized for the first time that it would be possible to produce genetic duplicates from all living organisms if a living cell from any part of the organism is available. 

Dolly Sheep Cloning Experiment

  • In 1997, Ian Wilmut and his team at Scotland’s Roslin Institute successfully cloned a sheep from the mammary glands of an adult female.
  • In the process, Scientists chose three sheep: Molly, Polly and Holly
Polly (Black face) They removed genetic material from her egg cell. Hence, the egg was acting as an empty vessel.
Molly (White face) Genetic material was extracted out of Molly’s cells and planted in Polly’s empty egg cell, creating an embryo. 
Holly The embryo was planted in Holly’s womb. Thus, Holly became a surrogate mother.


White-faced sheep named Dolly was born from the womb of Holly. But Dolly was a clone of Molly as its DNA was exactly the same as that of Molly. 


Type of Cloning

1. Molecular Cloning

  • It is the process of making multiple molecules.
  • It is widely used in biological experiments & practical applications ranging from genetic fingerprinting to large-scale protein production.

2. Animal Cloning

  • Discussed above

3. Human Cloning

Human cloning is further of two types

3.1 Reproductive Cloning

  • It involves delivering a baby by transferring the nucleus of an adult human cell to an enucleated human egg cell & allowing the manipulated egg cell to grow normally in the uterus of a surrogate mother.

3.2 Therapeutic Cloning

  • It involves using stem cells from the cloned human embryo to produce human organs & replacement tissues for medical purposes.
  • The organ thus produced contains the DNA of a sick person. Hence chances of organ rejection, in this case, are almost none. Along with that, the patient does not require to take immunosuppressant drugs for the remaining life, which is currently required during transplants.
  • Apart from that, it can help to understand the cause of genetic diseases and the process of cancer formation.

Positive effects of Cloning

  • Cloning can help as a backup system for human beings as vital organs like the heart, liver, kidneys etc., can be cloned.
  • It can help to produce plants and cells with favorable traits to be produced at a mass scale. 
  • It also aids in stem cell research.
  • Animal cloning has an application in saving endangered species. E.g., Chinese scientists successfully cloned Wild Arctic Fox, an endangered species native to Canada’s Queen Elizabeth Island, in an effort to save it from getting extinct.

Ethical Issues

  • Reproductive cloning can undermine respect for human life.
  • It may destroy social institutions like family, marriage etc.
  • It may lead to the loss of genetic diversity among humans.
  • Nations can raise cloned armies to fight against their enemies.
  • Clones may be used for slavery, which may constitute the sub-human race. 
  • Religious bodies also object to human cloning as interference in godly affairs.

Current Law

India Human cloning for reproductive purposes is banned.
UK In 2001, the UK became the first country to legalise Therapeutic Cloning.
United Nations UNGA has adopted a non-binding UN declaration on human cloning, calling for a ban on all forms of human cloning contrary to human dignity in March 2005.
USA Currently, there is no federal law to ban cloning completely. But 12 states have banned reproductive cloning & 3 states prohibit the use of public funds for this purpose.

Surrogacy and Issues

Surrogacy and Issues

This article deals with ‘Surrogacy and Issues – UPSC.’ This is part of our series on ‘Science and Technology’, which is an important pillar of the GS-3 syllabus. For more articles, you can click here.


  • Surrogacy is the practice in which one woman carries the foetus in her womb in an arrangement where the child has to be handed over after the birth. 
Surrogacy and Issues
  • Surrogacy can be of two types.
    1. Altruistic surrogacy: The couple doesn’t pay any compensation to the surrogate mother except for medical expenses. 
    2. Commercial surrogacy: Couple pays compensation to the surrogate mother.
  • India has a well-developed surrogacy industry with more than $2.3 billion annual revenue. 
  • India has emerged as a reproductive tourist industry. 

Surrogacy vs Pro Surrogacy Debate  (General)

Anti-Surrogacy Arguments

  • Physical stress, risk, and emotional trauma to surrogate mother on abrupt separation from baby carried in the womb for nine months.
  • Children face health concerns such as being breastfed for at least six months.
  • The use of surrogacy is cheapening the idea of having a child as a commodity.    
  • Sex selection is the ‘dirty secret’ of commercial surrogacy (the discarded foetus is usually female).

Pro-Surrogacy Arguments

  • The surrogate mother has the right to asset her independent agency and make choices in her best interest.
  • In case government bans surrogacy, the market will go underground, leading to further exploitation of surrogate mothers. Hence, instead of banning the practice, it should be regulated.

Surrogacy (Regulation) Act

Need for the law of Surrogacy

Post-2000 Surrogacy became a crucial medical industry in India, with more than $ 2.3 billion in revenue.
2008 Baby Manji case happened, and the need was felt to have a comprehensive law on Assistive Reproductive Techniques (ART).
2014 Assisted Reproductive Techniques (ART) Bill was introduced in Parliament (covering all aspects).
2016 Bill was introduced by the NDA government banning commercial surrogacy and allowing just Altruistic Surrogacy.
2019 Bill was re-introduced due to inherent deficiencies.
2021 The Bill was passed and became an act

In the absence of law, many problems were coming 

  1. Medical problems wrt foetus, e.g., the surrogate child is disabled or has any genetic disease and parents refuse to accept the child.
  2. Non-payment to surrogate mothers, especially when the child is born still or dead or born with a disability.
  3. Baby Manji Case (2008)Baby Manji was commissioned by Japanese parents (through an unknown egg donor and husband’s sperm) and was born to a surrogate mother in Gujarat. The parents divorced before the baby was born. The genetic father wanted the child’s custody, but Indian law barred single men from it, and Japanese law didn’t recognize surrogacy. The baby was ultimately granted a visa, but the case underscored the need for a regulatory framework for surrogacy in India.  
  4. Law Commission of India has recommended prohibiting commercial surrogacy and allowing altruistic surrogacy by enacting appropriate legislation.

Provisions of the Surrogacy Act, 2021

  • Defines Surrogacy: The Act defines surrogacy as ‘a practice where a woman gives birth to a child for an intending couple to hand over the child after the birth to the intending couple.’
  • It bans commercial surrogacy and allows only allows Altruistic Surrogacy.
  • The following can opt for surrogacy.
    1. Any heterosexual Indian couples or couples of Indian origin have a medical condition requiring gestational surrogacy.
    2. only for altruistic surrogacy purposes
    3. not for producing children for sale 
    4. prostitution, or other forms of exploitation
    5. Couples shouldn’t have any surviving child (either biological, adopted or surrogate)
  • The couple going for surrogacy should have a ‘certificate of essentiality’ and a ‘certificate of eligibility’ issued by the appropriate authority.
  • The couple can only approach a close relative for surrogacy. 
  • The surrogate child should be considered the biological child of the intending couple.
  • Regulatory Bodies: Regulatory bodies to regulate surrogacy clinics will be established at national and state levels
    • National Assisted Reproductive Technology & Surrogacy Board at the central level
    • State Assisted Reproductive Technology and Surrogacy Boards in the states
  • The act has also laid down the criteria for surrogate mothers, which include 
    1. Married women aged between 25 to 35 years having their own children.
    2. Can become a surrogate only once in her lifetime.
    3. Posses certificate of fitness for surrogacy
  • Insurance cover: 36 months for the Surrogate Mother to take care of all her medical needs and emergency conditions/complications.
  • Penalty: The penalty for going against the provisions of the act includes up to 10 years of imprisonment and a 10 lakh fine. 

Issues with the Act

  • An outright ban on surrogacy will push this industry underground, increasing the vulnerability of women even more. It was seen in Thailand
  • Act borrows heavily from the UK’s altruistic surrogacy Bill but has changed the British provision to allow only blood relatives to “close relatives”. Close Relative is a vague term open to legal challenges. Even the Select Committee has recommended changing the term ‘Close Relative’ with ‘Willing Woman.’
  • Violates Right to Equality: Restricting surrogacy to married Indian couples and disqualifying others based on nationality, marital status, sexual orientation or age does not appear to qualify the test of equality.  
  • Violate Article 21: Right to life includes the right to reproductive autonomy.
  • Supreme Court decriminalized homosexuality. Unfortunately, the Bill scarcely bears an imprint of the verdict & continues to speak the discriminatory language of Section 377.
  • The Bill violates UNDHR. Article 16 of the United Nations Declaration of Human Rights gives the right to men and women of full age to found a family. 


Last Updated: May 2023 (Telescopes)


This article deals with ‘Telescopes‘. This is part of our series on ‘Science and Technology, which is an important pillar of the GS-3 syllabus. For more articles, you can click here.

Important Telescopes

Important Telescopes for the purpose of exam include

  • 30 m Telescope ( Hawaii) 
  • National Large Solar Telescope ( Ladakh)
  • Atacama Large Millimeter Array (ALMA)
  • GROWTH India Telescope

It has to be noted that Light Pollution is a severe problem for Astronomers as artificial light from buildings, street lights, and malls makes it challenging to observe and study the stars in the sky. Hence,  Telescopes are set up in remote regions (far away from the cities).

Terrestrial Telescopes

1. Thirty-Meter Telescope

  • It is called Thirty Meter Telescope because its primary mirror is 30m wide.
  • After the E-ELT (European Extremely Large Telescope), it is the world’s highest and second largest telescope.
  • It is located at the Mauna Kea volcano summit in Hawaii (USA).
  • It is the joint project of India, Japan, the US, China, and Canada with $1.5 billion. 
  • India has financed 10% of the cost and will get proportional time for use. 
  • It observes between near UV to mid-infrared wavelengths and corrects the blur caused by the atmosphere by its adaptive optics system.

Controversy associated with Thirty-Meter Telescope

Three controversies are related to this project:-

  1. Mauna Kea is considered sacred by the local Hawaiian people.
  2. It presents a danger to the habitat of the Rare Weiku Bug found there.
  3. The land was given for use essentially rent-free.
Thirty-meter telescope

2. National Large Solar Telescope

  • NLST is being built by the Dept. of Science of Technology in Ladakh.
  • It will be the world’s largest solar telescope.
  • It can work both day and night.
  • It will fill the longitude gap between Japan and Europe. Currently, there is no telescope between these regions. 
  • It will help in understanding sunspots. Thus it will help protect satellite communication as sunspots pose a threat to their working. 

Why is Ladakh chosen?

  • Placement at a higher altitude will fundamentally enhance the NLST capacity.  
  • Prolong region of sunshine, clear sky (high visibility).
  • Low concentration of aerosol and dust particles in the atmosphere. 
  • Lower wind speed.
National Large Solar Telescope

3. Atacama Large Millimeter Array (ALMA)

  • ALMA is the joint venture of the USA, Japan, Canada, Taiwan, South Korea, and Chile. 
  • It is at 5000 meters. This place is most suitable as it is free from background noise, and the atmosphere is clean, dry and cool.
  • It consists of 66 high-precision antennas.
  • Aim: Explain very old and important astronomical anonymities and search for the origin of the Cosmos.
  • ALMA is the most powerful telescope used for observing the cold universe in which scientists study molecular gases and dust.
  • Using ALMA, astronomers have obtained high-resolution images of 20 nearby protoplanetary disks depicting the planet’s birth. 

Atacama Large Millimeter Array (ALMA)

4. Multi-Application Solar Telescope (MAST), Udaipur Solar Observatory

Purpose and Significance

  • For a detailed study of the Solar activity, including its magnetic field. 
  • The observatory is situated on an island in the middle of Fatehsagar lake. 
  • It is Asia’s biggest telescope.

Why is an observatory made in the middle of the lake? 

  • A large water body surrounding the telescopes decreases the amount of heating of the surface layers. 
  • It reduces the turbulence in the air mass and improves image quality. 
National Large Solar Telescope

5. Growth India Telescope

  • It is part of a multi-country joint initiative termed the Global Relay of Observatories Watching Transients Happen (GROWTH). 
  • The US, UK, India, Japan, Germany, Taiwan and Israel are part of this initiative.
  • Location: Hanle (Ladakh)
  • It is a fully robotic telescope and can be controlled remotely. 
  • Aim: Study cosmic events happening over relatively small periods of the cosmological timescale.

Telescopes in the Space

1. Astrosat

  • Astrosat is India’s first dedicated astronomy satellite (like Hubble of West).
  • It was launched in September 2015.


  • It can scan multi-wavelengths from ultraviolet to optical and low- and high-energy x-ray bands for studying distant stars, galaxies and other cosmic objects. 
  • It is situated at the height of 650 Km.
  • It has been of immense benefit to our scientists, who have depended on inputs from other agencies and sources like the Hubble [US-European space telescope]. 
  • It has put India in an elite orbit with the US, Europe, Russia and Japan.

2. James Webb Space Telescope

  • It is the Joint Venture of NASA, ESA & the Canadian Space Agency.
  • It is the scientific successor of the Hubble and Spitzer telescopes. 
  • The primary mirror of JWST consists of 18 hexagonal mirrors of 1.32 m diameter each (compared to Hubble Telescope with one mirror of 2.4 m diameter). Further, these mirrors are made up of beryllium as it is light and strong and coated with gold to increase the mirror’s reflection.
  • It will be placed at L2 (Lagrange Point), 930,000 miles from Earth’s surface. 
  • It has become NASA’s flagship infrared observatory. JWST carries four instruments
    1. Near-Infrared Camera (NIRCam),
    2. Near-Infrared Spectrograph (NIRSpec),
    3. Mid-Infrared Instrument (MIRI)
    4. Near-Infrared Imager and Slitless Spectrograph  
  • JWST will study the following
    1. Search for the very first galaxies that were formed after Big Bang. 
    2. Evolution of the galaxies until now. 
    3. Study formation of stars and their evolution in different phases.
    4. Potential to support life in these systems.
    5. Study solar systems, their planets, along with comets, asteroids and minor planets.

James Webb Space Telescope

3. Kepler

  • It was launched in 2009.
  • Aim: Survey the Milky Way galaxy region to discover planets in or around the habitable zone (Goldilocks Zone). 
  • It was orbiting the Sun, nearly 156 million km from the Earth.
  • Kepler is described as the most prolific planet-hunting machine in history. By June 2017, it had discovered more than 4,000 planet candidates and 2,300 confirmed planets.
  • Nov 2018: NASA’s Kepler space telescope has been retired after running out of fuel.

Side Topic: Goldilocks Zone

  • Goldilocks region denotes the area at the proper distance from its home star that it is neither at too high temperature nor too cold. 
  • Habitable exoplanets must have such a temperature in which water can exist in its liquid form. 

4. Hubble Space Telescope

  • Hubble Space Telescope was launched in Low Earth Orbit (LEO) in 1990 as a joint venture between NASA and the European Space Agency (ESA)
  • It used to orbit 550 km above Earth. 
  • Its main payloads include
    1. Wide Field and Planetary Camera (WF/PC), 
    2. Goddard High-Resolution Spectrograph (GHRS)
    3. High-Speed Photometer (HSP)
    4. Faint Object Camera (FOC)
    5. Faint Object Spectrograph (FOS).
  • These scientific payloads have helped uncover many secrets of the universe, including the theory of its expansion.

Hubble Space Telescope

5. Spitzer Space Telescope

  • NASA launched it in 2003.
  • Aim: To study the universe in the infrared
  • It was retired in January 2020.


Last Updated: May 2023 (UAVs)


This article deals with the ‘UAVs.’ This is part of our series on ‘Science and Technology’ which is an important pillar of the GS-3 syllabus. For more articles, you can click here.


  • UAV is an aerial vehicle without a pilot on board.  
  • UAVs can be remote-controlled aircraft (e.g. flown by a pilot on the ground) or fly autonomously based on the program. 

Applications of UAVs

Applications of UAV
  • UAVs can be remotely controlled. Therefore, it saves any loss of soldiers. 
  • In modern warfare, Armies use them in operations to have a view from above and coordinate the movement of Soldiers. 
  • Police are using them during rioting and monitoring people’s assembly during Strikes. E.g., Chandigarh Police  
  • UAVs can be used for real-time surveillance of rugged terrain.
  • Companies like Facebook plan to use it for internet delivery (Aquila).
  • Logistic companies are making drones to deliver products. E.g., Zomato is working on a hybrid drone for food delivery. Earlier, Amazon too tested such drones. 
  • Healthcare: Drones can be used for improving the delivery of medicines. E.g., the Telangana government’s ‘Medicine from the Sky’ project under which medicines (especially vaccines) will be transported from district headquarters to PHCs using a drone named Marut.
  • Agriculture: Drones have application in agro-management, especially in spraying pesticides, crop nutrients etc. In an experiment conducted in Brazil, the use of drones helped in reducing the use of pesticides.


  • Regulatory loopholes: There are policy and legal loopholes wrt the regulation of drones in India.
  • Quality Control: Most of the drones are imported in India.
  • Privacy Issues: Drones can collect images and data of common citizens infringing their right to privacy.
  • Use by Terrorists: These drones can be easily procured and used by terrorists for carrying out their nefarious activities. For example, drones are to drop weapons and drugs along the Punjab border. 
  • Issue with Air Traffic Management: Drones cant be detected by conventional radars and puts conventional air traffic in danger.

UAVs as a threat to National Security

Drones have changed the ways wars are fought and have posed new challenges to security agencies.

Recent developments in this regard include

  1. In 2021, Kashmiri terrorists dropped IEDs over Indian Airforce Base using UAVs.
  2. Pakistan use drones to smuggle drugs to India.
  3. In 2021, Azerbaijan defeated Armenia’s much more potent force using drones, which have completely changed the ways warfare is fought.
  4. Iran supported Shia Houthi rebels attacked oil facilities of Saudi Aramco and oil refinery in UAE, bypassing sophisticated missile defence systems.
  5. The US killed Iranian General Qasim Soleimani in a drone attack.

Ways to defend drone attacks 

The best way to defend is the installation of Anti-Drone systems. These includes

  1. Foreign Anti-Drone systems such as Iron Dome (of Israel), S-400 (of Russia), DroneHunter (of USA) etc.
  2. India is also making indigenous anti-drone systems. These include
    • DRDO’s ‘Anti-Drone System” can neutralize detecting the drones in the range of 3 km and destroy using laser technology.
    • Grene Robotics of Hyderabad has developed Anti-Drone System named ‘Indrajaal’. 
    • Naval Anti Drone System (NADS): First indigenously developed comprehensive anti-drone system developed by DRDO.  It has capabilities for both hard kill (attacking vital drone components) and soft kill (misguiding, signal jamming etc.). 
    • Israel’s SMASH 2000 Plus System: Being used by Indian Navy, this system is installed mainly on assault rifles providing hard kill option.

Drone Rules, 2021

  • Guidelines by Directorate General of Civil Aviation (DGCA) for use of civil drones.
  • Places restrictions on operating drones in certain areas (Red Zones). 
  • Provides for registration and licensing of drones and training of operators. 
  • It follows the principle of No Permission – No Take-off (NPNT) and permission is required before every operation of a drone.

Drones of India

#1. Indian Drones

1.1. Rustom

  • Rustom is developed by the Aeronautical Development Establishment (ADE) of Bangalore under DRDO.
  • It comes in two versions – Rustom 1 and Rustom 2.
  • Use: Intelligence, Surveillance and Reconnaissance (ISR

Features of Rustom

  Rustom-1 Rustom-2
Weight 95 Kg 350 Kg
Endurance 12-15 hour 24 hour
Range 250 km 250 km
Speed 125-175 km/hr 125-175 km/hr

1.2 Nishant

  • It is developed by the Aeronautical Development Establishment (ADE) of Bangalore under DRDO.
  • Primary use: Intelligence gathering, surveillance, target designation and damage assessment.
  • Features
    1. Endurance: 4 hours and 30 minutes.
    2. It has a range of 100 Km.
    3. It can reach up to a speed of 216 km/h.
    4. It is launched using a catapult and doesn’t need a runway.
    5. It has day and night flying capability.

1.3 Panchi

  • It is the wheeled version of Nishant. 

1.4 Lakshya-I

  • Lakshya-1 is pilotless target aircraft.
  • It is manufactured by HAL.
  • Primary use: Used to perform discrete aerial reconnaissance of battlefield and target acquisition.
  • Features
    1. Maximum Speed: 0.7 Mach
    2. Range: 150 km
    3. Its launch is rocket-assisted, while recovery is made using a two-stage parachute.
  • Later, the Nirbhay missile was also made from its design.


  • It is a Mini-UAV. 
  • It is developed by DRDO.
  • Its use includes following
    1. CRPF will use it to fight Naxals. 
    2. BSF in counter-insurgency. 
  • It has the following specifications
    1. Range of 4 to 5 km.
    2. Endurance of 40 to 60 minutes.
    3. It weighs around 6 kg.
Indian UAVs

#2. Foreign UAVs bought by India

2.1 Guardian Drone

  • India has bought  Guardian Drones (naval & unarmed version of Predator UAVs).
  • It has provided enhanced Indian capabilities in maritime defence.  
Guardian Drone

2.2 Heron TP

  • It is an Israeli Armed UAV.
  • India has bought this UAV.  
  • It is India’s first armed drone, significantly expanding the aerial offensive capabilities of the military.
Heron TP

2.3 Harpy and Harop

  • These UAVs are bought from Israel.

Indian Air Force

Last Updated: May 2023 (Indian Air Force)

Indian Air Force

This article deals with the ‘Indian Air Force.’ This is part of our series on ‘Science and Technology’ which is an important pillar of the GS-3 syllabus. For more articles, you can click here.


  • Indian Airforce with 1.27 active personnel defends the Indian airspace.
  • At present, the Indian Airforce (IAF) has 34 fighter squadrons. But to be effective against China and Pakistan, India needs at-least 45 squadrons.
Indian Air Force

Aircrafts of India

Combat Aircraft

Dassault Rafale 26
Sukhoi Su-30 MKI 272
HAL Tejas 22
Mig-29 66
Mirage 2000 49
Jaguar 120
MiG-21 Bison 107 (retire in 2025)

Reconnaissance Aircraft

Boeing 707 1
Global 5000 2
Gulfstream 2

Tanker Aircraft

Il-78 : 6

Transport Aircraft

Ilyushin IL-76 17
Boeing C-17 Globemaster 11
C-130J Super Hercules 12
Antonov A-32 104
Dornier 228 50


HAL Light Combat Helicopter Attack Helicopters
HAL Rudra Armed
HAL Dhruv Utility
Boeing Apache Attack Helicopters
Mi-24 Attack Helicopters
Chinook Heavy Transport


Harop Loitering Munition
Heron Surveillance
Searcher Surveillance
DRDO Lakshya Target Drone

Side Topic: Generations of Aircrafts

  Period Features Examples
1st Gen Fighters 1940s-50s Turbojet Engines Mig-15 and Mystere-IV
2nd Gen Fighters 1950s-60s Delta Wings
Guided and Beyond Visual Range Missiles
Mig-21, Su-7 and F-104
3rd Gen Fighters 1960s-70s Improved Radars, Missiles and Avionics Mig-25 and F-4 Phantom
4th Gen Fighters 1970s-90s Fly by wire controls
Multi-role capabilities
Mirage-2000, Mig-29, Su-27, F-16 Fighting Falcon
4.5th Gen Fighters 1990s onwards Some stealth features
Advanced avionics
Su-30 MKI, Rafale, Eurofighter Typhoon, F-16 Desert Falcon
5th Gen Fighters In development Advanced Stealth
Highly sophisticated avionics
Thrust Vectoring
Supersonic cruise without the use of afterburners
F/A-22 Raptor, F-35 and Sukhoi T-50

Detail of Combat Aircrafts in news

1. Rafale & MMRCA

Rafale is 4.5 generation Medium Multi-Role Combat Aircraft (MMRCA) aircraft made by Dassault Aviation of France.

Rafale and India

Main features of Rafale

  • 4.5 generation Multirole combat aircraft, i.e. can be used for ground support, in-depth strike, and anti-ship strike.
  • Rafale is capable of carrying nuclear weapons.
  • Equipped with precision air to air and air to surface missiles.
  • Range: 3,700 Km
  • Max Speed: 1,389 Km/hr
  • Load Carrying Capacity: 9,500 Kg

Rafale Acquisition: Chronology of Events

2007 Tender for MMRCA was invited, and various bidders such as  Eurofighter (of British Aerospace), F-16 (of Lockheed Martin), MiG-35 (of Russia) and Rafale (of Dassault (France)) applied for the bids.  
2011 Rafale was shortlisted. It was decided that India would buy 126 Rafale. In this, 18  were to be purchased in fly-away condition, and the rest 108 were to be made by HAL under Transfer of Technology.  
2015 But the issue was Dassault was not prepared to guarantee the performance of aircraft manufactured in IndiaThe plan was changed, and the government decided to buy 36 Rafale in the ready-to-fly condition given to India in two years.
2018-19 The case went to Supreme Court to increase the cost per aircraft and give offset contract to Reliance instead of HAL.  
2020 Delivery of Rafales started. The first batch of 5 aircraft was delivered to India.


  • The stealth system of Rafale is outdated compared to other competitors in the same class.
  • Rafale doesn’t have STOVL (Short take-off and vertical landing) capability, present in other competitors.
  • Brazilian Airforce was earlier interested in buying Rafale but later changed to Swedish Gripen jet.

2. Tejas / HAL’s LCA

  • HAL Tejas or Light Combat Aircraft (LCA) is a 4th Generation fighter aircraft made by India.
  • It is manufactured by Hindustan Aeronautical Limited (HAL).
  • The program to build indigenous Indian combat aircraft started way back in the 1980s. After long delays, the first Tejas was delivered to the Indian Airforce in 2015. In 2021, the Indian government announced to procure 83 Tejas.
  • Tejas is going to replace India’s ageing MiG 21 aircraft.
  • Features of HAL Tejas
    1. It has ~60% indigenous content.
    2. Maximum Speed: 1,350 Kmph.
    3. Its radius of action is 400 Km without refuelling.
    4. It can carry a weight of up to 12 tonnes. 
    5. Delta wing configuration 
    6. Numerous integrated technologies like Fly by wire flight control system, advanced digital cockpit, digital avionics, advanced composite material structure etc.
    7. It is equipped with operational capabilities like Beyond Visual Range Missile and Air to Air Refueling.
    8. It has STOBAR (Short Takeoff But Arrested Recovery) capability.

Side Topic: (LCA) Kaveri

  • Kaveri is the name of Tejas’s engine that was to be used, but India couldn’t make it on time to be used in the plane.
  • It would have been India’s first indigenous gas turbine engine.

3. Sukhoi T-50 (Fifth Generation)

Sukhoi T-50 is an Indo-Russian collaborative project to make 5th generation fighter aircraft. It is a joint venture of Russia’s Sukhoi and India’s HAL.

It will have the following characteristics

  1. Stealth features like specially designed airframes, engines intakes, and radar absorbing material
  2. Thrust vectoring nozzles
  3. One or two seated
  4. 30 mm cannon
  5. Eight weapon internal points and eight external points.
  6. Max speed of 2 Mach.
  7. Fuel capacity of 10,300 kg.

But in 2018, India has conveyed its unwillingness to Russia to go ahead with this project due to the high costs involved. 

Sukhoi T-50

Detail of Transport Aircrafts in news

1. C-17 Globemaster

  • It is a large military transport aircraft of US origin developed by Boeing. 
  • Indian Airforce has 11 Globemasters.
  • It can be used for
    1. Transporting troops.
    2. Maintaining supplies and carrying equipment to small airfields in remote and harsh terrain (E.g., Ladakh)
  • Its main features include
    1. Ability to take off from very high altitudes
    2. Land on paved as well as unpaved airfields during day and night.
C-17 Globemaster


Important Made in India Helicopters

1. Dhruv (ALH)

Dhruv Helicopter

Dhruv features of this helicopter

  • Dhruv was designed for the military as well as civilian purposes.
  • It is manufactured by Hindustan Aeronautics Limited (HAL).
  • It can play multiple roles: logistics, rescue and attack for Army, Navy, Airforce and Coast Guard.


  • The project was first announced in 1984 & was designed in assistance with MBB of Germany.
  • First flew in 1992 but developments prolonged due to budget restrictions and various restrictions placed on India after Pokhran 2 in 1998.
  • Entered into service in 2002. 
  • First exported to Nepal & Israel & is on order by several other countries.

2. LCH Prachand

  • LCH Prachand is indigenously developed by Hindustan Aeronautics Ltd.
  • It is a multi-role combat helicopter. With this, India has become the seventh country to make attack helicopters. 
  • Features of LCH Prachand
    1. Range: 550 Km
    2. Endurance: 3 hours
    3. Maximum height at which it can fly: 6.5 Km
    4. It is the only combat helicopter in the world which can land and takeoff at an altitude of 5,000 m.
    5. Equipped with a ‘COUNTERMEASURE DISPENSE SYSTEM‘ to protect it from enemy radars and missiles.
LCH Prachand

Foreign Helicopters bought by India

1. Chinook

  • Chinooks are the heavy-lift helicopters used by the US Army. 
  • India decided to buy 15 Chinook helicopters from the USA in 2016, and the first batch was delivered in 2019.
  •  Features of Chinook Helicopters
    1. Twin Engine with Tandem Rotor.
    2. Can carry up to 35 troops or 24 stretchers with 3 attendants or 10,500 kg payload.
    3. Advanced Avionics. 
    4. Advanced M240 Machine Gun

2. Apache

  • Apache is USA’s most advanced ‘attack helicopter’. 
  • India has bought 22 Apache Helicopters.
  • Features of Apache Helicopters
    1. Twin Turboshaft Engines
    2. Armed with missiles like Hellfire, Spike and Stinger missiles
    3. Armed with advanced M230 Chain Guns
    4. Night vision systems
    5. Advanced avionics

3. Mi-17

  • Mi-17 is a Russian origin transport helicopter manufactured by Kazan Helicopters.
  • It is one of the most advanced transport helicopters equipped with advanced features such as 
    1. Advanced self-defence system equipped with 23 mm cannon and heat-seeking missiles
    2. Twin-engine single rotor
    3. Highly sophisticated navigation and avionics system
    4. Maximum speed of 250 km/hr
    5. Range of 675 Km
    6. Payload capacity of 4,000Kg
    7. Capacity to transport up to 36 troops.
  • It is used for the transportation of VVIPs, including PM and army chiefs.