Science & Technology

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NASA-ISRO Synthetic Aperture Radar

Context: The NASA-ISRO Synthetic Aperture Radar (NISAR) satellite was successfully launched on 30th July 2025 from the Satish Dhawan Space Centre at Sriharikota in Andhra Pradesh.

The Geosynchronous Satellite Launch Vehicle (GSLV-F16) successfully lifted and precisely injected the NISAR satellite weighing 2,392 kg into its intended sun-synchronous orbit.

Relevance of the Topic: Prelims: Key facts about NASA-ISRO Synthetic Aperture Radar (NISAR) Mission.

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About NISAR: 

  • NISAR is a Low Earth Orbit (LEO) observatory which will be placed in sun-synchronous orbit at an altitude of 747 km and an orbit inclination of 98.4°. 
  • It is a joint project between NASA and the Indian Space Research Organization (ISRO) to develop and launch a radar imaging satellite. The satellite will be the first to use dual frequencies.
  • Duration: Baseline mission duration of three years. 
  • Estimated Mission Cost: $1.5 billion.
  • The Earth observation satellite is capable of penetrating cloud cover and operating day and night regardless of the weather conditions, expected to revolutionise earth-observing capability. NISAR will observe nearly all the planet’s land and ice surfaces twice every 12 days. 
  • The 2,800 kilograms satellite consists of both L-band and S-band synthetic aperture radar (SAR) instruments, which makes it a dual-frequency imaging radar satellite.
    • L-band SAR operates at a frequency of around 1 to 2 GHz. The lower frequency (higher wavelength) of L-band SAR allows it to penetrate through vegetation and soil, making it useful for monitoring changes in forest cover, soil moisture etc. 
    • S-band SAR operates at a frequency of around 2 to 4 GHz. S-band SAR has a higher resolution than L-band SAR and is typically used for applications where higher resolution is required, such as monitoring changes in urban areas or coastal zones.

Significance:

  • NISAR will observe natural processes and changes in earth’s complex ecosystems.
    • Study Earth’s dynamic land and ice surfaces in greater detail and observe subtle changes in Earth’s surfaces. E.g., Track flow rates of glaciers and ice sheets, landslide-prone areas and changes in the coastline etc.
    • Spot warning signs of natural disasters, such as earthquakes, tsunamis, volcanoes and landslides.
    • Measure groundwater levels, agricultural mapping, vegetation biomass, natural resource mapping and monitor Earth’s forest and agricultural regions to improve understanding of carbon exchange. 

Pralay Missile System

Context: The Defence Research and Development Organisation (DRDO) has successfully conducted two consecutive flight tests of the Pralay missiles from Dr. APJ Abdul Kalam Island, off the coast of Odisha. 

The missile followed a desired quasi-ballistic trajectory, demonstrated mid-air manoeuvres, and struck its designated target with hit-to-kill accuracy and pin-point precision.

Relevance of the Topic:Prelims: Key facts about Pralay Missile System. 

Pralay Missile System

  • Pralay is a short-range surface-to-surface missile developed for tactical battlefield use. 
  • The missile system is designed to meet the specific operational needs of the Indian Army and incorporates several indigenous technologies.

Key features of Pralay Missile: 

  • Propulsion system: Two-stage solid-propellant rocket motor with Manoeuvrable Re-entry Vehicle (MaRV) technology in the terminal stage.
  • Speed: Capable of reaching speeds between Mach 1 and Mach 1.6.
  • Range: Operational strike range of 150-500 kilometres.
  • Weight: Approximately five tonnes.
  • Flight trajectory: Quasi-ballistic and low-altitude trajectory, allowing it to evade early detection.
  • Guidance: Equipped with an inertial navigation system and integrated avionics for high-precision targeting and real-time trajectory correction.
  • Launch platform: Can be fired from an 8x8 BEML Tatra Transporter Erector Launcher, providing mobility and rapid deployment capability. 
  • Defence penetration: The missile can manoeuvre mid-flight, oscillate during travel, and alter its trajectory to evade enemy interception systems.
  • Survivability and effectiveness: Designed to resist interception, deliver precision strikes on short- and medium-range targets, and enhance battlefield readiness.
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Significance

The MoD has already cleared orders for Pralay missiles for the Indian Army and the Indian Air Force (IAF). 

  • The missile fills the gap of a conventionally armed ballistic weapon system and remains unaffected by the 'no first use' nuclear policy. 
  • Flexible and precise strike option that can be deployed rapidly in response to evolving threats. Deployed with conventional warheads along the borders, the missile can target radar and communication installations, command and control centres, and advanced airfields.
  • Enhances India’s tactical deterrence capabilities, strengthens India's strategic posture and promotes greater self-reliance in advanced defence technologies.

The successful completion of the phase-1 flight tests marks a crucial step toward the missile’s eventual induction into the Armed Forces. 

Pralay Missile System

Context: The Defence Research and Development Organisation (DRDO) has successfully conducted two consecutive flight tests of the Pralay missiles from Dr. APJ Abdul Kalam Island, off the coast of Odisha. 

The missile followed a desired quasi-ballistic trajectory, demonstrated mid-air manoeuvres, and struck its designated target with hit-to-kill accuracy and pin-point precision.

Relevance of the Topic: Prelims: Key facts about Pralay Missile System. 

Pralay Missile System:

  • Pralay is a short-range surface-to-surface missile developed for tactical battlefield use. 
  • The missile system is designed to meet the specific operational needs of the Indian Army and incorporates several indigenous technologies.

Key features of Pralay Missile: 

  • Propulsion system: Two-stage solid-propellant rocket motor with Manoeuvrable Re-entry Vehicle (MaRV) technology in the terminal stage.
  • Speed: Capable of reaching speeds between Mach 1 and Mach 1.6.
  • Range: Operational strike range of 150-500 kilometres.
  • Weight: Approximately five tonnes.
  • Flight trajectory: Quasi-ballistic and low-altitude trajectory, allowing it to evade early detection.
  • Guidance: Equipped with an inertial navigation system and integrated avionics for high-precision targeting and real-time trajectory correction.
  • Launch platform: Can be fired from an 8x8 BEML Tatra Transporter Erector Launcher, providing mobility and rapid deployment capability. 
  • Defence penetration: The missile can manoeuvre mid-flight, oscillate during travel, and alter its trajectory to evade enemy interception systems.
  • Survivability and effectiveness: Designed to resist interception, deliver precision strikes on short- and medium-range targets, and enhance battlefield readiness.
image 64

Significance: 

The MoD has already cleared orders for Pralay missiles for the Indian Army and the Indian Air Force (IAF). 

  • The missile fills the gap of a conventionally armed ballistic weapon system and remains unaffected by the 'no first use' nuclear policy. 
  • Flexible and precise strike option that can be deployed rapidly in response to evolving threats. Deployed with conventional warheads along the borders, the missile can target radar and communication installations, command and control centres, and advanced airfields.
  • Enhances India’s tactical deterrence capabilities, strengthens India's strategic posture and promotes greater self-reliance in advanced defence technologies.

The successful completion of the phase-1 flight tests marks a crucial step toward the missile’s eventual induction into the Armed Forces. 

Smart Meters

Context: The Power Ministry has extended the deadline for installing 25 crore smart meters across the country under the Revamped Distribution Sector Scheme (RDSS) by two years till March 2028.

Relevance of the Topic: Prelims: Key facts about Smart Meters; Revamped Distribution Sector Scheme.

Revamped Distribution Sector Scheme

  • Initiative of: Ministry of Power
  • Duration: 5 years i.e., from FY 2021-22 to FY 2025-26. Extended by two years till FY 2027-28.
  • Aim: To reduce the Aggregate Technical & Commercial (AT&C) losses to pan-India levels of 12-15% and Average Cost of Supply (ACS)-Average Revenue Realised (ARR) gap to zero by 2024-25.
  • The scheme has two parts: 
    • Part-A: Upgradation of distribution infrastructure and Pre-paid Smart Metering & System Metering. The Smart Meter National Programme under RDSS envisages the installation of 25 crore Smart Meters across the country.
    • Part-B: Training & Capacity Building and other Enabling & Supporting Activities.
  • Progress: As of July 2025, a total of 20.33 crore smart meters have been sanctioned under the RDSS, out of which 2.44 crore smart meters have been installed throughout the country.

Smart Meters:

  • Prepaid Smart Meters are the new generation of energy meters that are used to record electricity consumption in real-time. As they are connected to the internet, users and utilities can easily track and monitor electricity usage and get accurate bills. They can:
    • Eliminate the need for manual inspection, making them highly efficient and convenient.
    • Tell about electricity use during different times of the day, months and seasons.
    • Alert in case of insufficient/low balance or abnormal usage to best optimize their consumption on a user-friendly web portal or mobile app.
    • Notifies about changes in power tariffs that can help to plan activities during low-tariff periods.
    • Point towards appliances that are using more electricity than they should and suggests options to replace them with new, efficient ones.
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How does the Smart Meter Work?

Smart meters are digital devices that measure and record electricity (or gas or water) consumption in real time and relay the information to utility companies.

  • Metering device: For electricity meters, sensors measure the voltage and current flowing through the electrical circuits. These values are then multiplied to calculate the power consumption (measured in watts). By integrating the power consumption over time, the meter can determine total electricity use (measured in kilowatt-hours).
  • Transmit usage information: After recording energy consumption data, the communications module is responsible for transmitting usage information to the company, by using one of the following methods:
    • Radio frequency (RF) signals to transmit data. This method is cost-effective and allows for long-range communication. However, RF signals can be susceptible to interference from other wireless devices and might require more infrastructure, such as repeaters or gateways, to ensure reliable communication.
    • Cellular networks: Some smart meters rely on existing cellular networks (for example, 4G or 5G) to transmit data. This approach offers widespread coverage and can be more resistant to interference than RF signals.
    • Broadband connections  like DSL and fiber-optic networks are another option for smart meter communication.
    • Power line communication technology allows smart meters to transmit data over existing power lines, eliminating the need for additional communication infrastructure.

Way Forward:

As India marches towards its vision of a financially sound and digitalised power sector through smart metering interventions, it must pursue a user-centric design and deployment strategy. 

  • Spread Awareness: The Ministry of Power should drive a nationwide campaign to educate consumers about smart meter benefits and improve the uptake of smart meter apps. The apps should be accessible to users from diverse socio-economic backgrounds and provide actionable tips and information.
  • Capacity Building: The majority of smart meters in India are being deployed by the Advanced Metering Infrastructure Service Providers (AMISPs), responsible for installation and operation of the AMI system for the project lifetime (10 years). Discoms must closely work with AMISPs to ensure a smooth installation and recharge experience for users, to leverage smart meter data for revenue protection and consumer engagement. For this, discoms will need to strengthen their internal capacity through suitable staffing and training interventions.
  • Foster Innovation: Discoms, system integrators and technology providers should collaborate to devise innovative and scalable data solutions. Effective use of smart meter data is fundamental to unlocking their true value proposition. This would require an ecosystem that fosters innovation in analytics, data hosting and sharing platforms, and enables key actors to collaboratively test and scale new solutions.
  • Strengthen Regulatory framework: Policymakers and regulators must strengthen regulations to empower consumers to unlock new retail markets.
    • Currently, important provisions concerning the phase-out of paper bills, arrear adjustment, frequency of recharge alerts, buffer time, rebates, and data privacy are scattered across different regulatory orders or simply missing. Their incorporation within existing State frameworks will be crucial for a positive technology experience for end users.
    • Regulators must also enable simplification and innovation in tariff design and open the retail market to new business models and prosumagers (producers, consumers, and storage users). 

India’s 1st Private Test Facility for Heavy Water Upgrade

Context: Mumbai-based TEMA India has been entrusted with testing the equipment required for upgrading of depleted heavy water, a crucial requirement for Pressurised Heavy Water Reactors in India. It is a significant step towards speeding up the operationalisation of nuclear power plants. 

Relevance of the Topic: Prelims: India’s 1st private test facility for Heavy Water Upgrade; Heavy Water; Pressurised Heavy Water Reactors. 

India’s 1st Private Test Facility for Heavy Water Upgrade

  • Until now, the assembling and testing of equipment for heavy water upgrade were centralised and done by Bhabha Atomic Research Centre (BARC).
  • TEMA India has inaugurated its test facility at Achchad in Palghar district, Maharashtra, where it will manufacture equipment such as distillation columns and integrate and test them before sending them to reactor sites for installation.
  • The facility was designed and built by TEMA India’s nuclear vertical under technology transfer from BARC and a ‘purchase order’ from Nuclear Power Corporation of India Ltd (NPCIL).

Significance:  

  • Single-point solutionfor upgrading heavy water:
    • Till now, the distillation columns and modules were manufactured by other vendors, and then assembled and tested by BARC. The entire process took 7-8 years. 
    • The decentralisation will reduce the time period by at least one to two years, and thus speeden up the operationalisation of nuclear power plants. 

What is Heavy Water?

  • Heavy water (D2O) is a form of water (H2O) with deuterium (a heavier isotope of hydrogen), instead of regular hydrogen. 
  • It is used as a coolant as well as moderator for slowing down fast-moving neutrons during a chain reaction essential for sustaining the nuclear fission process.
  • D2O needs to be 99.9% pure for working efficiently. With time it gets contaminated with light or regular water, thus requiring the depleted D2O to be upgraded back to 99.9% using a distillation process. 
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TEMA India has dispatched the first batch of tested distillation column sections for deployment at a unit of the Rawatbhata Nuclear Power Plant (RAPP-8) in Rajasthan, which is scheduled to go critical by December 2025.

Pressurised Heavy Water Reactor:

  • Fuel: Natural Uranium (unenriched) 
  • Moderator and Coolant: Heavy water is used as both moderator and coolant. 
  • Cooling System: Uses a combination of heavy water and light water to cool the reactor. Heat is transferred to a secondary loop, which then generates steam to drive turbines.
  • Control Rods: Boron or Cadmium control rods.
  • Fuel requirement: Annual requirement of fuel (UO2) of a 700 MW PHWR (at 85% Capacity Factor) is about 125 tons. 
  • Advantages: Uses natural Uranium fuel, produces less high-level radioactive waste, and operates at lower pressures compared to some other reactor types.
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India’s Nuclear Energy Generation Target

  • India has set its eyes at achieving 100 GW of installed nuclear energy capacity by 2047. 
  • There are 24 nuclear reactors operational in India with an installed capacity of 8780 MW. 
  • The government had approved construction of 10 more nuclear reactors in 2015- of which one has come onboard, while the rest (with a combined capacity of 13.6 GW) are under construction. 
  • The immediate target is to achieve 22.4 GW of installed capacity by 2032. 
  • The government has also launched a 20,000-crore Nuclear Energy Mission to develop Small Modular Reactors.

Also Read: Nuclear Energy Sector in Union Budget 2025-26 

PARAM-1: India’s Foundational LLM 

Context: In July 2025, the government-backed BharatGen released PARAM-1, a bilingual Large Language Model (LLM) built from scratch to reflect India’s linguistic and cultural realities, focusing on Hindi and English.

Relevance of the Topic: Prelims: Key Features of PARAM-1.

Foundational AI

  • Foundational AI: Large-scale AI models trained on very large datasets and over which numerous specific applications can be built, including generative AI. 
  • Large Language Models (LLMs) are a type of Foundational AI model trained with vast datasets with at least one billion or more parameters. E.g., AI-powered tools like ChatGPT, Gemini, Perplexity, DeepSeek, Grok. 
  • Small Language Models (SLMs) are compact AI systems typically having fewer than 1 billion parameters (ranges from millions to a few billion parameters). Cheaper to run and maintain, and ideal for specific use cases. 

In its mission to build open source Large Language Models (LLMs) for Indian researchers and developers, BharatGen, the government-backed AI Initiative, has released a LLM called PARAM-1.

About PARAM-1 

  • PARAM-1 is a 2.9-billion parameter bilingual foundational AI model developed by the BharatGen team. 
  • It reflects India’s linguistic and cultural realities- with 25% of its training data in Hindi and the rest in carefully curated English. 

Key Features: 

  • Bilingual focus: Trained in Hindi and English, incorporating government documents, literary works, educational and community content.
  • Script-aware Tokeniser: 
    • Tokeniser is the first step in how a language model processes text. It breaks sentences into smaller units, or tokens, which the model can interpret.
    • Standard tokenisers (built for English) perform poorly on Indian scripts, splitting words into too many fragments. 
    • PARAM-1 addresses this with a script-aware tokeniser that recognises Hindi and other Indic scripts, creating fewer and more meaningful tokens. This improves both accuracy and efficiency.
  • Three-phase training focuses on language fluency, factual consistency, and long-context understanding. This allows the model to gradually develop fluency, retain factual information, and improve performance on tasks that require reading and reasoning over longer texts.
  • India-centric evaluation: Tested on Indian benchmarks like MILU (competitive exam questions) and SANSKRITI (cultural knowledge), besides global ones like MMLU and ARC.

Limitations:

  • Currently supports only Hindi and English, excluding India’s wider linguistic diversity. Raises concerns over the model’s inclusivity, especially in a country where linguistic identity often intersects with regional politics and access to services.

Molecular Imaging: Caltech’s Angstrom-Scale Microscope 

Context: Scientists at the California Institute of Technology (Caltech) have developed a breakthrough imaging technique that enables real-time filming of Brownian motion (molecular motions). This imaging technique indirectly detects molecules by observing their interactions with light and tapping into Brownian motion. 

Relevance of the Topic: Prelims: Basic idea about working of Microscope; Brownian motion; Applications of high-resolution Molecular Imaging. 

Conventional Microscope

  • Conventional light microscopes work by using visible light to magnify and resolve small objects or structures. 
  • Limitations: 
    • Conventional microscopes are invasive (disturb or damage the sample being studied) either physically, chemically, or by introducing heat or radiation. 
    • Have limited fields of view. They can not distinguish individual molecules, which are around tens of Angstroms in size (1 Angstrom = 0.0000000001 m). 

Brownian Motion: 

  • Brownian motion is the random movement of particles in a fluid (liquid or air) due to their collisions with other atoms or molecules. The more massive a particle, the slower its Brownian motion. 
  • Examples of Brownian Motion include:
    • The motion of pollen grains on still water
    • Movement of dust motes in a room (although largely affected by air currents)
    • Diffusion of pollutants in the air
    • Diffusion of calcium through bones
    • Movement of "holes" of electrical charge in semiconductors.
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Breakthrough Imaging Technique

  • The breakthrough imaging technique utilises Brownian motion, ultrafast lasers, and light-matter interaction to indirectly detect and visualise molecular behaviour by observing their interactions with light. 
  • Their technique taps into the Brownian motion of particles. By measuring how fast a molecule changes the properties of light, researchers could determine its size. 
    • The more massive a particle, the slower its Brownian motion. 
    • Small molecules spin fast and disturb the light more than larger ones. This fact allows the size estimation of molecules by observing their interaction with light. 
  • Benefits of the Microscope: Non-invasive; Can help visualise molecular sizes in real-time at the Angstrom scale (higher resolution). No existing technique till date has achieved this level of detail.
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Significance: This new imaging technique could help better visualise processes and transform biomedical research, disease detection, drug design, and nanomaterial fabrication. 

Applications of high-resolution Molecular Imaging:

  • Early detection of diseases (like cancer, cardiovascular, neurodegenerative) by visualising specific biomarkers associated with disease progression. 
  • Drug design and targeted drug delivery: Help researchers visualise delivery of drugs to specific tissues or cells, and optimise the design of nanocarriers for improved therapeutic outcomes.
  • Efficient electronics: Observing the movement of electrons, and manipulating it to design more efficient electronic devices.
  • Nanomaterial fabrication: Helps understand molecular processes in nanomaterial synthesis. 

Also Read: Nobel Prize in Physics for Attosecond Physics 

Vitamin D deficiency linked to Neurodevelopmental Issues

Context: A major study published in The Lancet Psychiatry has found a potential link between neonatal vitamin D levels and the risk of developing neurodevelopmental disorders such as schizophrenia, ADHD, and Autism.

Relevance of the Topic: Prelims: India’s Vitamin D Problem; Vitamin D. 

Vitamin D deficiency linked to Neurodevelopmental Issues

  • Researchers from Denmark used dried blood spot samples (Danish Neonatal Screening Biobank) from over 88,000 individuals born between 1981 and 2005.
  • From these samples, the team measured levels of:
    • 25-hydroxyvitamin D or 25(OH)D which is the standard marker of vitamin D status. 
    • Vitamin D-binding protein which carries vitamin D in the blood and prolongs its activity.
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Key Findings of the Study:  

  • Babies with higher vitamin D levels were less likely to be diagnosed with schizophrenia, ADHD, or autism.
  • Newborns with levels about 12.6 nmol/l higher than average had an 18% lower risk of schizophrenia, an 11% lower risk of ADHD, and a 7% lower risk of autism. 
  • Vitamin D-binding protein levels were also linked to schizophrenia risk.
  • Researchers found no strong link between low vitamin D levels at birth (neonatal vitamin D) and the risk of depression or bipolar disorder later in life.

Limitations of the Study:  

  • Nearly all participants were of European Ancestry.
  • In a smaller non-European group, the results were less consistent, possibly due to lower vitamin D levels, smaller sample size, and/or genetic diversity. 
  • Gene variants may influence both vitamin D and neurodevelopment, a phenomenon known as pleiotropy. 
  • Vitamin D measured only at birth- the study could not pinpoint a critical window during pregnancy.

India’s Vitamin D Problem

  • India has a high Vitamin D deficiency rate despite abundant sunlight.
  • A study conducted at AIIMS Rishikesh between 2017 and 2018 found that 74% of infants and 85.5% of their mothers were deficient in vitamin D, with nearly half experiencing severe deficiency. 
  • A 2024 study conducted in the Bundelkhand region of India found a strong positive correlation between mothers’ and their infants’ vitamin D levels and interpreted it to mean babies born to vitamin D-deficient mothers were very likely to be deficient themselves.
  • However, findings also suggest that timely supplementation in deficient mothers can remarkably improve both maternal and neonatal levels.

Vitamin D insufficiency is not just an individual issue: it is a biological legacy passed from one generation to the next, shaping not just bones but brains too. India must move from reactive treatment to proactive care through awareness, screening, and timely supplementation.

Apache AH-64E Helicopters 

Context: In a significant fillip to modernisation of military aviation capabilities, the Indian Army received the first batch of three Apache AH-64E helicopters from the US at the Hindon airbase. 

Relevance of the Topic:Prelims: Key facts about Apache AH-64E Helicopters. 

 Apache AH-64E Helicopters

  • The AH-64E Apache is one of the world's most advanced multi-role combat helicopters.
  • Manufactured by: Boeing, the US. 

Key Features:

  • Warhead: The choppers are fitted with:
    • Hellfire air-to-surface anti tank missile
    • Stinger air-to-air missiles
    • 70 mm Hydra rockets
    • 30 mm automatic cannons
  • Advanced Technology: AH-64E incorporates 26 new technologies to enhance battlefield performance. These include:
    • Advanced Digital Connectivity
    • Joint Tactical Information Distribution System
    • Powerful T700-GE-701D engines with enhanced transmissions
    • Improved rotor blades made of composite materials
    • Ability to control unmanned aerial vehicles (UAVs) mid-flight (allowing manned-unmanned teaming in real time). 
  • Sensors & Radar: Equipped with Longbow Fire Control Radar:
    • capable of simultaneously tracking up to 128 targets and engaging up to 16 at once
    • Fire-and-forget capability when combined with Hellfire missiles
    • All weather operation capability. 
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Significance: The induction of Apache combat helicopters strengthen India’s operational capabilities against Pakistan along the Western Border and high-altitude areas. 

  • Can approach enemy troops covertly with relative stealth and launch as close range attack
  • Capability to operate in hostile airspace with threats from ground.
  • Capability to destroy enemy tanks, armoured personnel carriers and fortified positions in mountainous terrain.
  • Provides cover to army tanks and infantry during battle.

Armed Forces and Apache Helicopters

  • The Indian Air Force (IAF) has 22 Apache Helicopters which are used for air defence and deep-strike roles targeting enemy radar installations and command posts.
  • The Indian Army intends to use its fleet for close air support, tank-busting missions and battlefield dominance during armoured engagements. India signed a Rs 5691 crore deal in 2020 for 6 Apaches, specifically for the Indian Army. 

Key Facts: 

  • In early 2025, the Ministry of Defence signed a Rs 62,700 crore (approximately $7.3 billion) contract with Hindustan Aeronautics Limited (HAL) for 156 ‘Prachand’ Light Combat Helicopters, underscoring the increasing role of rotorcraft in India’s war-fighting doctrine.
  • These helicopters- 66 for the IAF and 90 for the Indian Army- will be delivered over the next five years. This would be a significant development unfolding on the Eastern front.

MiG-21 Fighter Jets to Retire

 Context: After protecting the skies for more than six decades, the MiG-21 Bison fighter jets of the Indian Air Force are set to retire in September 2025. The plans are to replace them with indigenously developed Tejas Mk1A fighter aircraft. 

Relevance of the Topic:Prelims: Key facts about MiG-21 Fighter Jets. 

MiG-21 Fighter Jets: India’s First Supersonic Fighter

  • MiG-21 is a single-engine supersonic jet fighter and interceptor aircraft.
  • Developed by: Mikoyan-Gurevich Design Bureau in the former Soviet Union.
  • Induction: First procured in 1963 into the Indian Air Force (IAF). They formed the backbone of the Air Force till the mid-2000s, when the Su-30MKIs were inducted. 
  • Initially developed as an interceptor, the supersonic jet was eventually upgraded to perform as a multi-role combat aircraft, including ground attacks.
  • With a maximum speed of 2230 kilometres per hour, the jet carries one 23mm twin-barrel cannon with four R-60 close combat missiles. 
  • Key Role: They have played key roles in the wars with Pakistan (1965 and 1971), Kargil War (1999), Balakot air strikes (2019), and the most-recent Operation Sindoor (2025).

Variants of MiG-21 Fighter Jets: 

  • Over the years, India procured more than 700 MiG-21 aircraft of different variants. Many were domestically built by Hindustan Aeronautics Ltd. They include- Type 74 or MiG 21F; Type 76 or MiG 21PF; Type 77 or MiG 21FL; Type 96 or MiG 21M; Type 75 or MiG 21 Bis (upgraded Type 96); and MiG-21 Bison. 
image 47

MiG-21 Fighter Jets to Retire

  • The Air Force currently has two MiG-21 squadrons, or 36 aircrafts, that are operated by the squadrons stationed at the Nal airbase in Rajasthan.
    • Indian Air Force (IAF) has 31 fighter squadrons as against the sanctioned strength of 42 squadrons. It is significantly below the optimal readiness requirements.
    • The phase out of two MIG-21 squadrons has been long extended due to the delayed deliveries of LCA-Mk1A (Tejas fighter aircraft). After the phased out, the combat strength of the Air Force will drop to 29 squadrons. 

Controversy: 

  • The MiG-21 aircrafts have been involved in several accidents, leading to the deaths of 170 pilots and 40 civilians. They were once termed “Flying Coffin”. 

Also Read: Race for Fighters: the IAF’s dilemma 

How GLP-1 Drugs Work?

Context: Two GLP-1 drugs- Novo Nordisk’s semaglutide and Eli Lilly’s tirzepatide, are now available in the Indian market. 

Mounjaro, Ozempic, Wegovy, Semaglutide, Tirzepatide belong to a class of glucagon-like peptide-1 (GLP-1) receptor agonists, originally developed to treat diabetes and obesity.

Relevance of the Topic:Prelims: Key facts about GLP-1 Drugs. 

What are GLP-1 Drugs?

  • GLP-1 is an incretin hormone and a neurotransmitter naturally secreted from the small intestine and hindbrain in the human body, after one eats a meal. It travels to the pancreas, where it helps to regulate blood sugar by increasing insulin and decreasing glucagon.
  • GLP-1 RA (glucagon-like peptide-1 receptor agonists) are a new class of drugs that mimic naturally-occurring gut hormones called incretin (GLP-1 is one such incretin). Thus, they regulate appetite and digestion, helping users feel full faster and consume fewer calories.
  • Semaglutide and Tirzepatide both mimic the action of GLP-1. Tirzepatide additionally also mimics the action of another hormone called GIP (glucose-dependent insulinotropic polypeptide).

How GLP-1 Drugs Work?

GLP-1 drugs impact centres in the brain associated with control of hunger and satiety, to effectively tell us that we have had enough to eat and need to stop eating. They work by:

  • improving the secretion of insulin that allows more of the glucose in the bloodstream to enter cells where it can be used for energy. 
  • inhibiting the secretion of the hormone glucagon that stimulates the liver to release stored glucose into the bloodstream.
  • slowing down the emptying of the stomach so that the glucose levels in the bloodstream does not spike.  
  • reducing appetite by signalling to the brain that one is satiated.

The drugs can be self-administered by the patient once a week via subcutaneous injection (similar to insulin). Semaglutide is also available as an oral tablet. 

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Utility of GLP-1 Drugs: 

  • Weight loss: Extremely effective for weight-loss helping people lose on an average 15% to 20% of their body weight, equivalent to otherwise lost with bariatric surgeries.
  • Diabetes: GLP-1 drugs infusion significantly increases insulin levels and lowers glucose levels in diabetic patients.
  • Alzheimer’s: Some evidence shows that the drugs are associated with lower risk of Alzheimer’s and Dementia.
  • Other Conditions: Found to be effective and are being studied for conditions including- cardiovascular diseases, kidney disease, non-alcoholic fatty liver disease, and obstructive sleep apnoea. Studies have shown a 69% reduction in heart failure events. 

Potential Side Effects of GLP-1 Drugs: 

  • Common side effects include- nausea, vomiting, acidity, burping, hiccups, diarrhoea, abdominal pain, and appetite loss. 
  • Rarer complications include- pancreatitis, retinal changes (necessitating eye exams), and increased risk of medullary thyroid carcinoma, especially for those with a family history.  

Confined field trials on Genetically Modified (GM) Maize

Context: Punjab Agricultural University (PAU) is set to begin confined field trials of genetically modified (GM) Maize in the ongoing kharif season. 

PAU has received approval from the Review Committee on Genetic Manipulation (RCGM), under the Department of Biotechnology, along with formal consent from the Punjab state government.

Relevance of the Topic: Prelims: Key facts about GM crops; GM Maize; Regulations related to GM crops. 

Confined Field Trials of GM Maize

  • PAU will conduct confined field-trials of two varieties of transgenic Maize in collaboration with Bayer Crop Science Limited (formerly Monsanto).
  • GM Maize has been genetically engineered with both herbicide-tolerant (HT) and insect-resistant Bacillus thuringiensis (BT) traits.
    • Herbicide-tolerant (HT) Maize: To study weed-control efficacy in herbicide-tolerant maize hybrids with the application of Glyphosate-K salt.
    • Insect-resistant (IR) Maize: To study the efficacy of insect-protected maize hybrids against targeted lepidopteran pests (stem borer; fall armyworm).
  • Confined field trials are small-scale field experiments to address the biosafety requirements and evaluate the performance of specific traits in genetically engineered plants.

Criticism of Confined field trials of GM Maize trials: 

Anti-GMO activists have expressed strong opposition to the project. The concerns include- 

  • Unintended environmental consequences including the risk of gene flow into nearby farms or wild varieties. Trials pose risks of genetic contamination and long-term ecological damage.
  • Risk of potential long-term health risks associated with GM food products.
  • Introduction of GM crops in India (even for research or confined trials) sets a dangerous precedent, particularly in Punjab where agricultural ecology is already under stress. Glyphosate-tolerant Maize trails are controversial as glyphosate (a herbicide) is currently banned in Punjab due to its negative impacts on human health and the environment.
  • Lack of transparency and insufficient public consultation. Bayer’s involvement has been questioned given the global controversies surrounding GM seed patent enforcement.

The organisations have demanded transparency on the scientific basis for the approval and raised concerns over biosafety violations in previous GM crop trials at PAU. 

PAU Maintains that:

  • Trials were permitted only after receiving clearance from the Government of India’s Review Committee on Genetic Manipulation (RCGM), under the Department of Biotechnology.
  • Biosafety Research Level 1 (BRL-I) trials (preliminary) and Advanced level II (BRL-II) trials would be carried out under strict standard operating procedures, with mandatory permission from state-level committees.

Review Committee on Genetic Manipulation (RCGM) is the regulatory authority for BRL-1 trials (size limited to no more than one acre/trial site location).

Genetic Engineering Appraisal Committee (GEAC) is the regulatory authority for Biosafety Research Level II (BRL- II) trials (size is generally limited to no more than 2.5 acres/trial site location).

What are GM Crops?

  • Genetically Modified (GM) crops are plants that have had their DNA modified (altered) through genetic engineering.
    • It involves inserting new DNA into the genome of a plant. 
    • The seeds produced by these plants will inherit the new DNA.
  • E.g., BT cotton is a genetically modified variety of cotton that contains genes from the bacterium Bacillus thuringiensis. 
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Benefits of GM crops:

  • Genetic modification is done to transfer a particular trait to the plant in order to:
    • Increased the yield of a crop
    • Increased nutritional content of a crop
    • Developing resistance to:
      • Abiotic stresses like temperature, salinity or herbicide-resistant
      • Biotic stresses like insect-resistant crops.

Regulations related to GM crops: 

  • Genetically Modified Organisms (GMOs) and their products are regulated under the “Rules for the Manufacture, Use, Import, Export and Storage of Hazardous Microorganisms/ Genetically Engineered Organisms or Cells, 1989.”
  • The rules are notified under the Environment (Protection) Act, 1986. These rules regulate the use, research, and commercialisation of GMOs, especially for environmental and biosafety concerns. 
  • The commercial cultivation and the field trials of GM crops require clearance from the Genetic Engineering Appraisal Committee (GEAC) under the Ministry of Environment, Forest and Climate Change. 
  • After the GEAC clearance, the state governments have the power to approve (or reject) the field trials of particular GM crops in their respective states.

Status of GM crops in India

  • BT cotton is the only GM crop that is commercially allowed for cultivation in India from 2002. 
  • Field trials of GM Mustard (DMH-11) were approved by GEAC in 2022, but its commercial release is still pending. 

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