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GS Paper: GS3-15.Science and Technology- Developments and their Applications and Effects in Everyday Life.

  • Akash Missile System 

    Why in the News?

    India has pitched for the supply of the Akash missile system to Brazil.

    akash

    About Akash Missile System:

    • Overview: Developed by the Defence Research and Development Organisation (DRDO) and manufactured by Bharat Dynamics Ltd (BDL).
    • Type: A short-range Surface-to-Air Missile (SAM) designed to defend against aircraft, UAVs, and helicopters.
    • Operational Users: Inducted by both the Indian Army and the Indian Air Force, forming part of India’s layered air defence grid.
    • Purpose: Protects vital assets from aerial threats within the short to medium range segment.
    • Deployment Mode: Mounted on mobile launchers for rapid positioning, flexibility, and operational agility.
    • Comparison: Functionally comparable to Israel’s Iron Dome, though Akash focuses on intercepting larger aerial targets rather than small projectiles.

    Key Features:

    • Range & Altitude: Effective range 4.5–25 km; altitude coverage 100 m–20 km.
    • Engagement Capacity: A single firing unit can engage four targets simultaneously in both autonomous and group modes.
    • Speed & Accuracy: Capable of high-speed interceptions with radar-guided precision.
    • Propulsion & Dimensions: Length 5.87 m, diameter 350 mm, weight 710 kg; powered by solid-fuel propulsion.
    • Automation: Fully automated system ensuring rapid reaction time from detection to neutralization.
    • ECCM Capability: Built-in Electronic Counter-Counter Measures (ECCM) to resist enemy jamming
    [UPSC 2023] Consider the following statements:

    1. Ballistic missiles are jet-propelled at subsonic speeds throughout their fights, while cruise missiles are rocket-powered only in the initial phase of flight.

    2. Agni-V is a medium-range supersonic cruise missile, while BrahMos is a solid-fuelled intercontinental ballistic missile.

    Which of the statements given above is/are correct?

    Options: (a) 1 only (b) 2 only (c) Both 1 and 2 (d) Neither 1 nor 2*

     

  • SARAL tool to simplify Scientific Research Papers

    Why in the News?

    The Anusandhan National Research Foundation (ANRF), India’s newest science funding agency, has launched a digital tool called SARAL (Simplified and Automated Research Amplification and Learning) to make scientific research more accessible.

    What is Anusandhan National Research Foundation (ANRF)?

    • Establishment: Created under the ANRF Act, 2023, replacing the Science and Engineering Research Board (SERB).
    • Nature: Acts as India’s apex science funding and policy-making body.
    • Mission & Objectives: 

      • Raise India’s R&D spending from 0.7% to 2% of GDP by 2030.
      • Mobilise 70% private sector participation in research funding.
      • Promote interdisciplinary research across sciences, technology, health, agriculture, humanities, and social sciences.
      • Align research with Viksit Bharat 2047 and the National Education Policy (NEP).
    • Structure:

      • Chairperson: Prime Minister of India (ex-officio).
      • Vice Presidents: Union Ministers of Science & Technology and Education.
      • Member Secretary: Principal Scientific Advisor.
      • Guided by a Governing Council and Executive Council for policy and funding.

    About SARAL:

    • Developer: Created by IIIT Hyderabad under the guidance of the Anusandhan National Research Foundation (ANRF).
    • Purpose: Designed to make complex research papers accessible to students, professionals, and the general public.
    • AI Use: Generates summaries in multiple formats such as slides, videos, posters, and podcasts.
    • Language Support: Available in 11 Indian languages, ensuring wider inclusivity in science communication.
    • Workflow: Users upload research papers (LaTeX, arXiv links, PDFs); AI divides into sections (Introduction, Methodology, Results, Discussion, Conclusion); it produces editable slides and video summaries.
    • Significance:
      • Democratises science by converting research into layman-friendly outputs.
      • Enhances science communication and outreach.
      • Builds awareness of cutting-edge research across disciplines.
    [UPSC 2015] Which of the following statements is/are correct regarding National Innovation Foundation-India (NIF)?

    1. NIF is an autonomous body of the Department of Science and Technology under the Central Government.

    2. NIF is an initiative to strengthen the highly advanced scientific research in India’s premier scientific institutions in collaboration with highly advanced foreign scientific institutions.

    Select the correct answer using the code given below:

    (a) 1 only* (b) 2 only (c) Both 1 and 2 (d) Neither 1 nor 2

     

  • [pib] Siphon-Based Thermal Desalination System

    Why in the News?

    Researchers at the Indian Institute of Science (IISc) have developed a siphon-based thermal desalination system that overcomes siltation issues, offering a low-cost and scalable solution.

    About Siphon-Based Thermal Desalination System:

    • Overview: Developed by Indian Institute of Science (IISc) researchers to overcome the inefficiencies of conventional solar stills.
    • Purpose: Designed as a low-cost, scalable, and sustainable freshwater solution for off-grid and water-stressed regions.
    • Working: 

      • Principle: Works on siphonage, where a fabric wick draws salty water and gravity maintains continuous flow.
      • Innovation: A grooved metallic surface flushes away salt deposits before crystallization, preventing clogging.
      • Process: Salty water evaporates as a thin film on a heated surface and condenses just 2 mm away on a cooler surface, ensuring high efficiency.

    Key Features:

    • High Efficiency: Generates >6 liters of freshwater per sq. m per hour under sunlight — several times more than conventional solar stills.
    • Multistage Design: Uses stacked evaporator–condenser pairs to recycle heat and boost output.
    • Salt Resistance: Handles up to 20% salinity without clogging, making it effective even for brine treatment.
    • Affordable Materials: Built from aluminum and fabric, keeping costs low.
    • Energy Flexibility: Operates on solar power or waste heat, adaptable to different settings.
    • Scalable Applications: Useful for villages, disaster zones, and island communities.
    • Sustainability: Offers a clean, low-maintenance desalination method without reliance on complex machinery.
    [UPSC 2008] Where was the first desalination plant in India to produce one lakh liters of freshwater per day based on low-temperature thermal desalination principle commissioned?

    Options: (a) Kavaratti * (b) Port Blair (c) Mangalore (d) Valsad

     

  • Delhi to witness Artificial Rain through Cloud Seeding

    Why in the News?

    The Delhi government is planning to trial cloud-seeding to trigger artificial rain to combat air pollution ahead of winters.

    About Cloud Seeding:

    • About: It is a microclimate management technique aimed at altering precipitation patterns by dispersing substances into clouds to stimulate rainfall or snowfall.
    • Why it is used: It is used to mitigate hail, disperse fog, and either induce precipitation or prevent it from occurring in subsequent days.
    • Techniques include:
      • Static Cloud Seeding: Chemicals are introduced into cold clouds already containing supercooled water droplets, encouraging the formation of ice crystals.
      • Hygroscopic Cloud Seeding: Salts are sprayed into the base of warm clouds to act as condensation nuclei, increasing the number and size of water droplets.
      • Dynamic Cloud Seeding: This method involves boosting vertical air currents to enhance moisture passage through the clouds, leading to more rain.
    • Common Cloud Seeding Chemicals:
      • Silver iodide (AgI): Preferred for its ice-like crystalline properties.
      • Potassium iodide (KI): Functions similarly to silver iodide.
      • Dry ice (solid CO): Used to rapidly cool cloud droplets, aiding rain formation.
      • Liquid propane: Used in specific cloud types, effective at higher temperatures.
      • Sodium chloride and calcium chloride: Used in hygroscopic (warm) cloud seeding methods.
      • Bismuth tri-iodide (BiI): Sometimes used based on experimental or environmental considerations.
    • Dispersion methods range from aircraft and ground-based generators to newer approaches like drones delivering electric charges or infrared laser pulses.

    Limitations: 

    • Concerns persist regarding the potential accumulation of seeding agents in sensitive ecosystems, although detailed studies have shown negligible impacts.
    • The chemicals used, such as silver iodide, may potentially damage the environment and cause health issues like iodine poisoning in high concentrations
    [UPSC 2025] Artificial way of causing rainfall to reduce air pollution makes use of:

    (a) silver iodide and potassium iodide *

    (b) silver nitrate and potassium iodide

    (c) silver iodide and potassium nitrate

    (d) silver nitrate and potassium chloride

     

  • What is Portable Ion Chromatography?

    Why in the News?

    Australian scientists have developed a simpler, portable version of ion chromatography called Aquamonitrix, enabling field-based analysis of nitrate and nitrite ions.

    About Ion Chromatography:

    • Overview: A laboratory technique used to separate and measure ions (charged particles) in a sample.
    • Process: A liquid sample is passed through a long column that separates ions based on their properties.
    • Equipment: Requires large, complex, and costly lab machines.
    • Use in Environment: Detects harmful ions like nitrate and nitrite that pollute soil and water.

    What is Aquamonitrix?

    • Overview: A portable ion chromatograph designed by the University of Tasmania (Australia).
    • Features: Small, battery-operated, and nearly 10 times cheaper than lab equipment.
    • Testing: Students tested it on soil pore water, measuring nitrate and nitrite levels accurately when compared with lab results.
    • How it Works?
      • Soil water collected with a vacuum pump and filtered.
      • Water injected into the Aquamonitrix unit.
      • Uses a sodium chloride solution to carry the sample.
      • Equipped with a UV light detector, showing nitrate and nitrite as clear peaks.
      • Simpler design avoids messy interference from multiple ions.

    Applications:

    • Environment: Monitoring nitrate and nitrite pollution in soil and water.
    • Agriculture: Helps optimise fertiliser use and reduce overuse.
    • Water Safety: Tests drinking water quality on site.
    • Education: Serves as a teaching tool linking classroom to real-world chemistry.
    [UPSC 2024] “Membrane Bioreactors” are often discussed in the context of:

    Options: (a) Assisted reproductive technologies

    (b) Drug delivery nanotechnologies

    (c) Vaccine production technologies

    (d) Wastewater treatment technologies*

     

  • [pib] Adi Vaani App: India’s First Tribal AI Translator

    Why in the News?

    The Ministry of Tribal Affairs has launched the Beta Version of “Adi Vaani”, India’s first AI-based translator for tribal languages.

    About Adi Vaani:

    • What is it: India’s first AI-powered translator for tribal languages.
    • Launch: Released in Beta Version (2025) by the Ministry of Tribal Affairs.
    • Inception: Developed under Janjatiya Gaurav Varsh to empower tribal communities and safeguard endangered tribal languages.
    • Created by: A team led by IIT Delhi with BITS Pilani, IIIT Hyderabad, IIIT Nava Raipur, and Tribal Research Institutes.
    • Impact: Strengthens digital literacy, ensures inclusive governance, preserves cultural identity, and positions India as a global leader in AI for endangered languages.

    Key Features:

    • Translation Modes: Text-to-Text, Text-to-Speech, Speech-to-Text, and Speech-to-Speech.
    • Languages (Beta): Santali, Bhili, Mundari, and Gondi. Kui and Garo to be added next.
    • AI Models: Based on NLLB (No Language Left Behind) and IndicTrans2, adapted for low-resource languages.
    • Community-Driven: Data collected, validated, and iteratively developed by local experts and Tribal Research Institutes.
    • Toolkit Additions: OCR for digitizing manuscripts, bilingual dictionaries, and curated repositories.
    [UPSC 2020] With the present state of development, Artificial Intelligence can effectively do which of the following?

    1. Bring down electricity consumption in industrial units 2. Create meaningful short stories and songs

    3. Disease diagnosis 4. Text-to-Speech Conversion

    5. Wireless transmission of electrical energy

    Options: (a) 1, 2, 3 and 5 only (b) 1, 3 and 4 only* (c) 2, 4 and 5 only (d) 1, 2, 3, 4 and 5

     

  • ClassGPT: How AI is reshaping campuses

    Introduction

    Artificial Intelligence (AI), particularly generative models like ChatGPT and Gemini, has become both a boon and a challenge in higher education. Students increasingly rely on AI for assignments, summaries, coding, and even emails, while faculty members grapple with maintaining originality, academic honesty, and critical thinking. With AI growing faster than existing regulatory or pedagogical frameworks, Indian institutions are experimenting with varied approaches, ranging from outright bans to integration into curricula. The choices made today will determine not just the future of learning but also India’s knowledge economy and workforce readiness.

    The Changing Landscape of Education with AI

    How widespread is AI usage among students and teachers

    1. IIT Delhi Survey (2024): Four out of five students admitted to using AI, often several times a week. One in ten subscribed to premium versions.
    2. Faculty usage: 77% of surveyed teachers used AI for summarising papers, creating slides, or drafting communication.
    3. Student motivations: Simplification of concepts, summarisation of material, mind maps, and scenario simulations.
    4. Concerns: Errors in math, flawed debugging, weak context handling.

    The integrity dilemma in classrooms

    1. Blurred lines: Students question whether using AI counts as “cheating” or “time-saving.”
    2. Academic honesty: IIT Delhi’s committee recommended rewriting plagiarism policies to require disclosure of AI use.
    3. Critical thinking loss: Faculty fear students may accept AI answers as “Truth” without questioning them.

    Institutional responses in India

    • Policy innovations:
      1. IIT Delhi – integration of AI/ML in curricula, AI workshops, campus-wide licenses.
      2. IIIT Delhi – shifted evaluation to 90% exams, 10% assignments.
      3. IIM Ranchi – evaluation rubric for responsible AI integration.
      4. Shiv Nadar University – five-level “Gen AI Assessment Scale” from prohibition to responsible autonomy.
      5. Ashoka University – AI literacy courses, foundation modules, ethics of AI curriculum.
      6. Strict resistance: Some universities (Delhi University’s Dept. of Education) enforce “No AI” policies, insisting on handwritten assignments.
    • Pedagogical experiments with AI
      1. Classroom integration: AI tools are increasingly used to automate routine tasks like code generation, freeing classroom time for higher-order problem-solving.
      2. Assessment innovation: Institutions are shifting towards interactive methods such as AI-assisted viva voce, project-based evaluation, and scenario testing to ensure genuine understanding.
      3. Ethics in curriculum: Courses on “Ethics of AI” and AI literacy modules are being introduced to sensitise students towards responsible and transparent usage.
      4. Balanced usage: AI is deployed after core concepts are taught, ensuring students retain critical thinking and do not outsource judgment entirely.

    Global responses and comparative perspectives

    1. USA: Princeton provides ChatGPT licenses; Oxford mandates disclosure but allows professors to decide; assignments redesigned to integrate AI.
    2. Australia: TEQSA guidelines legitimise AI but require mandatory disclosure; oral exams and viva voce are making a comeback.
    3. UK: Universities pilot TeacherMatic to ensure sector-wide learning models.

    Conclusion

    Generative AI has irreversibly entered the Indian classroom. The challenge is not whether to allow or ban it but how to regulate, integrate, and ethically harness it. From IITs’ committees to global universities’ adaptive models, the world is learning that AI can either weaken critical thinking or be a catalyst for higher-order learning. For India, the stakes are especially high: with its demographic dividend and growing tech economy, how students learn today will define the nation’s competitiveness tomorrow.

    Value Addition

    Real-Time Usage of AI in Education

    1. Adaptive Learning Platforms : AI customises lesson plans, adjusting pace and difficulty based on student performance, ensuring personalised learning outcomes.
    2. Automated Assessment and Feedback : AI evaluates tests, essays, coding tasks, and provides instant feedback, saving teacher time and helping students improve faster.
    3. Language Translation and Accessibility : Real-time translation, speech-to-text, and text-to-speech tools remove linguistic barriers, supporting multilingual and differently-abled learners.
    4. AI-Powered Virtual Tutors : Chatbots and digital assistants are available 24×7 to clarify doubts, simulate problem-solving, and provide personalised tutoring.
    5. Plagiarism and Academic Integrity Checks : AI tools detect plagiarism and even AI-generated content, ensuring transparency and originality in student submissions.
    6. Immersive Learning with AI + AR/VR : Virtual labs and simulations powered by AI allow safe, hands-on learning in science, medicine, and engineering.
    7. Administrative Automation : AI automates attendance, timetabling, grading records, and performance monitoring, reducing non-teaching workload for faculty.
    8. Industry 4.0 Skill Development : AI-based coding assistants, real-time debugging, and project simulators prepare students for jobs in data science, robotics, and emerging tech.

    PYQ Relevance

    [UPSC 2023]  Introduce the concept of Artificial Intelligence (AI). How does AI help clinical diagnosis? Do you perceive any threat to privacy of the individual in the use of AI in the healthcare?

    Linkage: AI’s growing role in education parallels its use in healthcare, where it aids efficiency but raises ethical and privacy concerns. Just as AI in clinical diagnosis demands accuracy, transparency, and accountability, AI in classrooms requires disclosure, integrity, and critical oversight. Both contexts highlight the larger governance challenge of balancing innovation with responsibility.

  • How are Soaps and Detergents manufactured?

    Why in the News?

    This newscard is an excerpt from the original article published in ‘The Hindu’.

    About Soap:

    • Composition: Soap is sodium (Na) or potassium (K) salt of fatty acids derived from vegetable oils or animal fats.
    • Formula: Solid soaps are RCOONa, liquid soaps are RCOOK.
    • Function: Cleansing agent due to dual hydrophilic (water-attracting) and hydrophobic (oil-attracting) nature.
    • History: Used since 2800 BC in Mesopotamia and ancient India (soap nuts, bark, flowers). Became mass-produced during the Industrial Revolution, initially a luxury.

    Soap-Making Process

    • Raw Materials: Oils such as coconut, olive, palm, sunflower provide triglycerides.
    • Hydrolysis: Oils hydrolysed with hot water under pressure → fatty acids + glycerin.
    • Saponification: Fatty acids react with sodium hydroxide (NaOH) → soap (RCOONa) + water.
    • Processing: Soap dried into noodles, blended with perfumes, colours, fillers, additives.
    • Shaping: Extruded, cut, and stamped into bars.
    • Quality: Total Fatty Matter (TFM) indicates quality; higher TFM = better cleansing.
    • Production Scale: Modern automated lines make 600–700 soaps per minute.

    Ecological Impact of Soap

    • Biodegradability: Traditional soaps are biodegradable and safer for the environment.
    • Detergents: Synthetic alternatives developed during World War I oil shortages; more efficient but harmful.
    • Pollution: Surfactants and phosphates in detergents cause nutrient pollution and persist in ecosystems.
    [UPSC 2002] Consider the following statements:

    Assertion (A) Synthetic detergents can lather well in hard water.

    Reason (R): Synthetic detergents form soluble calcium and magnesium salts with hard water.

    Which one of the following is correct in respect of the above statements?

    Options:

    (a) Both A and R are individually true and R is the correct explanation of A *

    (b) Both A and R are individually true but R is not a correct explanation of A

    (c) A is true but R is false

    (d) A is false but R is true

     

  • How does satellite internet work?

    Why in the News:

    Elon Musk’s Starlink will soon launch in India, promising high-speed internet access in regions beyond the reach of ground-based networks. This is significant as it can bridge rural-urban gaps, improve disaster resilience, and strengthen defence capabilities. Globally, satellite internet has been a lifeline during Hurricane Harvey and a tactical tool in the Russia-Ukraine war. For India, it represents both a technological leap and a strategic necessity.

    Introduction:

    In today’s digitised and interconnected world, internet access is as vital as electricity or transport. Traditional cable and tower-based networks excel in cities but falter in remote terrains. Satellite internet, powered by mega-constellations like Starlink, offers a borderless, high-resilience alternative that operates irrespective of geography.

    Why are ground-based internet networks economically unviable in certain regions?

    1. Physical Infrastructure Limits: Cables and towers are uneconomical for sparsely populated or remote regions
    2. Disaster Vulnerability: Infrastructure can be wiped out during floods, earthquakes, or storms
    3. On-the-Go Connectivity Gap: Mobile and temporary operations (airplanes, ships, oil rigs) often remain underserved

    How does satellite internet overcome these challenges?

    1. Global Coverage: Operates regardless of terrain or terrestrial infrastructure
    2. Rapid Deployment: Can be set up quickly to meet sudden demand surges
    3. Mobility Advantage: Supports moving platforms and remote sites
    4. Dual-Use Potential: Functions for both civil and military purposes (e.g., Ukrainian defence, Siachen Glacier operations)

    What makes the new wave of satellite internet significant?

    1. Mega-Constellations: Networks like Starlink have thousands of satellites in Low Earth Orbit (LEO)
    2. Disaster Response Role: Viasat aided Hurricane Harvey operations when 70% of cell towers failed.
    3. Defence Integration: Ukrainian drones fitted with Starlink to bypass Russian jamming; Indian Army use in high-altitude conflict zones
    4. Security Concerns: Smuggled Starlink devices used by insurgent groups and drug cartels

    Working of satellite internet:

    1. Two Segments: Space segment (satellites) and ground segment (user terminals, gateways).
    2. Service Life: Satellites operate for 5–20 years depending on design.
    3. Orbits:
      1. GEO (35,786 km): Wide coverage, high latency; unsuitable for real-time apps. Example: Viasat GX.
      2. MEO (2,000–35,786 km): Medium latency, requires constellations. Example: O3b.
      3. LEO (<2,000 km): Low latency, small coverage; requires mega-constellations. Example: Starlink’s 7,000+ satellites.

    Key Differences between satellites in GEO, MEO AND LEO:

    Feature Geostationary Earth Orbit (GEO) Medium Earth Orbit (MEO) Low Earth Orbit (LEO)
    Altitude 35,786 km above equator 2,000 – 35,786 km Below 2,000 km
    Relative Motion Stationary relative to a point on Earth Moves relative to Earth Moves quickly relative to Earth
    Coverage ~1/3 of Earth (no polar coverage) Larger than LEO, smaller than GEO; needs constellation for global coverage Small footprint; single satellite covers area like an Indian metro city
    Satellite Size Large Large Smaller, often table-sized
    Cost & Deployment Expensive, long deployment Expensive, smaller constellations Cheaper, quicker to deploy
    Latency High (unsuitable for time-sensitive apps) Medium (lower than GEO but still limits real-time use) Very low (good for real-time use)
    Example Viasat Global Xpress (GX) O3b constellation (20 satellites) Starlink (7,000+ satellites, aiming for 42,000)
    Key Drawback High delay due to distance Still costly, latency not ideal for all uses Needs thousands of satellites for global coverage

    How do LEO mega-constellations maintain connectivity?

    1. On-Board Processing: Improves efficiency and reduces terminal complexity
    2. Optical Inter-Satellite Links: Satellites communicate directly in space for faster routing
    3. Seamless Handoff: Steerable antennas track multiple satellites to maintain uninterrupted service

    What are the key applications of satellite internet?

    1. Civil Connectivity: Rural broadband, IoE (Internet of Everything)
    2. Transportation: Navigation, self-driving cars, logistics optimisation
    3. Public Administration: Smart cities, disaster warnings, rescue coordination
    4. Healthcare: Telemedicine, remote diagnostics
    5. Agriculture: Precision farming, crop health monitoring
    6. Defence & Security: Real-time communication in conflict zones, strategic surveillance

    Conclusion

    Satellite internet represents not just a technological upgrade but a strategic asset in the digital era. For India, it offers a pathway to bridge the digital divide, enhance national resilience, and project influence in the global communications domain. However, its dual-use nature demands strong regulatory frameworks to balance innovation, accessibility, and security.

    Value Addition

    Key Terms & Phrases Explained

    • Satellite Internet: A communication service where internet connectivity is provided through satellites orbiting the Earth, rather than terrestrial cables/towers. It enables access in remote, disaster-hit, or mobile scenarios.
    • Mega-Constellation: A large network of hundreds or thousands of satellites, often in Low Earth Orbit (LEO), working in coordination to provide continuous coverage. Example: Starlink (planned 42,000 satellites).
    • Latency: Time taken for a signal to travel from sender to receiver; critical for real-time applications like video conferencing or online gaming.
    • Optical Inter-Satellite Links (OISL): Laser-based connections between satellites, enabling direct space-to-space data transfer without routing through ground stations, reducing delays and congestion.
    • Dual-Use Technology: A technology with both civilian and military applications. In satellite internet, the same network can support remote learning and healthcare or battlefield communication and drone operations.
    • Digital Divide: The socio-economic gap between those with access to modern digital technologies (internet, computing) and those without.
    • International Telecommunication Union (ITU): A UN agency responsible for coordinating global telecom networks, including orbital slot and spectrum allocation for satellites.
    • On-Board Processing: Satellite’s ability to process data directly in orbit, improving signal quality, speed, and reducing complexity of user terminals.
    • Seamless Handoff: Automatic switching of user connection from one satellite to another as satellites move, ensuring uninterrupted service.
    • Internet of Everything (IoE): An extension of IoT where not only devices, but also data, processes, and people are interconnected via the internet.

    Mapping  Micro Themes

    Paper Macro Theme Micro Themes Sub-Micro / Example
    GS Paper III Types of Orbits GEO (Geostationary) INSAT series, GSAT satellites
    MEO (Medium Earth Orbit) O3b constellation for broadband
    LEO (Low Earth Orbit) Starlink, OneWeb
    GS Paper III Application in Navigation GNSS Variants GPS (USA), GLONASS (Russia), Galileo (EU), IRNSS/NavIC (India)
    LEO & MEO in Navigation Faster signals, better coverage
    GS Paper II Policy & Governance India’s Space Policy 2023 PPP in satellite communication
    International Coordination ITU spectrum allocation

    Practice Mains Question:

    Discuss the potential of satellite internet in bridging the digital divide in India. Examine the associated security and regulatory challenges.

    PYQ Linkage:

    [UPSC 2018] Why is the Indian Regional Navigational Satellite System [IRNSS] needed? How does it help in navigation? 

    Linkage: IRNSS (also called NavIC) is India’s indigenous satellite-based navigation system providing accurate position information over India and surrounding regions.

    Just like IRNSS uses satellites for positioning, satellite internet uses similar orbital infrastructure for data connectivity. Understanding satellite orbits, latency, and ground segments from this topic directly aids in explaining IRNSS’s working, advantages, and strategic value in navigation.

     

  • [pib] MSS+ Technology in Road Construction

    Why in the News?

    The CSIR–Central Road Research Institute, New Delhi, has developed MSS+ (Modified Mix Seal Surfacing Plus) technology for eco-friendly, durable, and low-cost road surfacing.

    About MSS+ Technology:

    • Developer: Council of Scientific & Industrial Research – Central Road Research Institute (CSIR–CRRI), New Delhi.
    • Year of Development: 2021 (in collaboration with J.M.V.D. Industries).
    • Pilot Project: First road in Uttar Pradesh built near Lucknow in 2022; Used for 202 km of roads under Pradhan Mantri Gram Sadak Yojana (PMGSY) in 2025.
    • Composition: Crushed natural aggregate, customised modified bitumen emulsion, mineral admixture.
    • Preparation: Mix made at ambient temperature, eliminating heating of aggregate or bitumen.
    • Laying: 25–30 mm thickness using conventional asphalt pavers.

    Benefits Offered:

    • Eco-Friendly: No thermal process → significantly reduces carbon emissions.
    • Durable: Provides strong wearing course, enhanced skid resistance, and prevents water infiltration.
    • Cost-Effective: Reduced energy requirement lowers construction costs.
    • All-Weather Use: Can be laid in varied weather conditions due to ambient temperature application.
    [UPSC 2020] In rural road construction, the use of which of the following is preferred for ensuring environmental sustainability or to reduce carbon footprint?

    1. Copper slag 2. Cold mix asphalt technology 3. Geotextiles 4. Hot mix asphalt technology 5. Portland cement

    Select the correct answer using the code given below:

    Options: (a) 1, 2 and 3 only * (b) 2, 3 and 4 only (c) 4 and 5 only (d) 1 and 5 only