Science & Technology is one of the most current-affairs-driven and application-oriented parts of GS Paper 3 — questions track live developments (Chandrayaan, the James Webb Telescope, COVID vaccines, AI, semiconductors) and reward candidates who can explain the science and its socio-economic impact. The sharpest way to prepare is to study what UPSC has already asked. This resource gives you a clean, topic-wise bank of Science & Technology PYQs from 2013 to 2025, then reads that bank like data: what recurs, what is surging, and what is likely in 2026.

The Data: Which Sci-Tech Themes Does UPSC Ask Most?

Tagging all GS3 Science & Technology questions from 2013–2025 by theme (some overlap) reveals two enduring pillars — space technology and biotechnology & health — with a fast-rising cluster of frontier & strategic tech (AI, semiconductors, fusion, nanotech).

Reading the Trend Lines: A Data Scientist's View

The direction of change is as revealing as the counts. Five signals stand out:

• Space is the section's fingerprint: Chandrayaan (2023, 2017), the Mars Orbiter Mission, IRNSS/NavIC (2015), the space station plan (2019) and the James Webb Telescope (2022) recur reliably — always paired with socio-economic application.
• Frontier tech is the breakout trend: The 2025 paper alone featured semiconductors, fusion energy (ITER) and nanotech-in-agriculture, joining AI (2023) and robotics (2015) — a decisive shift toward strategic, dual-use technology.
• Biotech & health are evergreen: Vaccines (2022, COVID), stem cells (2017), biopharma (2018), antibiotic resistance (2014) and applied biotech-for-the-poor (2021) appear across the whole period.
• Energy tech is resurging: From fast breeder reactors (2017) and nuclear (2018) to fusion/ITER and clean-tech (2025) — mirroring the net-zero and energy-independence push.
• The "impact" angle is mandatory: Almost every question demands the socio-economic, ethical or security implication (AI & privacy, TKDL & open-source, nanotech & farmers) — not just the science.

The 2026 Forecast: Probability-Ranked Predictions

Science & Tech answers reward a concept + application + implication structure: explain the science simply, give its Indian application (mission/scheme), then evaluate the socio-economic, ethical or security impact. — Legacy IAS Faculty

Topic-Wise PYQ Bank: GS3 Science & Technology (2013–2025)

The complete bank, organised by theme for focused revision and answer practice. Year (and word limit, where specified) are tagged.

1. Space Technology

• What is the main task of India's third moon mission (Chandrayaan-3) that could not be achieved earlier? List countries that have achieved it; explain the subsystems and the role of the 'Virtual Launch Control Centre' at VSSC. (2023)
• James Webb Space Telescope (launched 25 Dec 2021) — its unique features vs predecessors, key goals and potential benefits for humanity. (2022)
• What is India's plan to have its own space station and how will it benefit our space programme? (2019)
• India has succeeded in unmanned missions (Chandrayaan, MOM) but not manned — examine critically the technological and logistical obstacles to a manned mission. (2017)
• Discuss India's achievements in space science & technology and how its application has aided socio-economic development. (2016)
• What are 'Standard Positioning System' and 'Precision Positioning System' in the GPS era? Discuss the advantages of the IRNSS programme. (2015)

2. Biotechnology, Health & Life Sciences

• How does nanotechnology offer advancements in agriculture, and how can it uplift the socio-economic status of farmers? (2025, 250w)
• Introduce AI — how does it help clinical diagnosis? Do you perceive any threat to privacy in AI in healthcare? (2023)
• Discuss the several ways microorganisms can help meet the current fuel shortage. (2023)
• What is the basic principle behind vaccine development? How do vaccines work? What approaches did Indian manufacturers adopt for COVID-19 vaccines? (2022)
• Each year, cellulose is deposited on Earth — what natural processes does it undergo before yielding CO₂, water and other end products? (2022)
• What are the R&D achievements in applied biotechnology and how will they uplift poorer sections of society? (2021)
• What is nanotechnology and how is it helping in the health sector? (2020)
• Why is there so much activity in biotechnology in India, and how has it benefitted biopharma? (2018)
• Describe stem cell therapy and its advantages over other treatments. (2017)
• Can overuse and free availability of antibiotics contribute to drug-resistant diseases? Discuss monitoring and control mechanisms. (2014)

3. Frontier & Strategic Technology (AI, Semiconductors, Nano, Robotics)

• India aims to be a semiconductor manufacturing hub — challenges and salient features of the India Semiconductor Mission. (2025, 250w)
• What are the areas of prohibitive labour that can be sustainably managed by robots? Discuss initiatives to propel research. (2015)
• Why is nanotechnology a key 21st-century technology? Describe the salient features of the Indian Government's Mission on Nanoscience & Technology. (2016)
• The 2014 Physics Nobel (Akasaki, Amano, Nakamura) for Blue LEDs — how has this invention impacted everyday life? (2021)

4. Nuclear & Energy Technology

• India's fusion energy programme & ITER — India's contributions and the implications of the project's success for global energy. (2025, 150w)
• How can India achieve energy independence through clean technology by 2047, and biotechnology's role? (2025, 150w)
• With growing energy needs, should India keep expanding its nuclear energy programme? Discuss the facts and fears. (2018)
• Give an account of the growth of nuclear science & technology in India — what is the advantage of the fast breeder reactor programme? (2017)
• What is a Run-of-river hydroelectricity project and how is it different from other hydro projects? (2013)

5. IPR, Patents & Traditional Knowledge

• How is the government protecting traditional knowledge of medicine from patenting by pharma companies? (2019)
• Broadly distinguish between Copyrights, Patents and Trade Secrets in a globalized world. (2014)
• India's Traditional Knowledge Digital Library (TKDL) — discuss the pros and cons of making it publicly available under open-source licensing. (2015)
• The 2005 circumstances forcing amendment to Section 3(d) of the Patent Law — how did the SC use it to reject Novartis's 'Glivec' patent? Pros and cons. (2013)
• What are Fixed Dose Drug Combinations (FDCs)? Discuss their merits and demerits. (2013)

6. IT, Cyber & Digital Technology

• Describe the context and salient features of the Digital Personal Data Protection Act, 2023. (2024)
• Social media and encrypted messaging pose a security challenge — measures adopted and further remedies. (2024)
• The technology for electronic toll collection on highways — advantages, limitations, proposed seamless changes and potential hazards. (2024)
• (a) What is a digital signature and its authentication? (b) How does 3D printing work — advantages and disadvantages? (2013)
• COVID-19 — give an account of how technology was availed to aid pandemic management. (2020)

7. Basic Science, Materials, Defence & R&D

• What are asteroids? How real is the extinction threat, and what strategies prevent such a catastrophe? (2024)
• How is the S-400 air defence system technically superior to any other system available? (2021)
• Discuss the work of 'Bose-Einstein Statistics' by Prof. S.N. Bose and how it revolutionized physics. (2018)
• Scientific research in Indian universities is declining — critically comment. (2014)
• (a) What is an FRP composite material, how is it made, and its uses in aviation/automobiles? (2013)
• What is the Umpire Decision Review System (DRS) in cricket? Discuss its components and how silicone tape may fool it. (2013)

How to Use These PYQs (Answer-Writing Strategy)

1. Master the space + biotech core: Keep ready notes on ISRO missions (Gaganyaan, Chandrayaan, NavIC), vaccines, stem cells and gene editing — the twin signature themes.
2. Own the frontier-tech shift: Build material on AI, semiconductors (ISM), quantum, nanotech and fusion — the fastest-rising demand.
3. Always add the "impact" layer: Socio-economic, ethical (AI & privacy) or security implications — UPSC expects it in almost every question.
4. Structure = concept + application + implication: Explain the science simply, cite the Indian mission/policy, then evaluate the impact.
5. Feed in current affairs: Every new mission, policy (BioE3, ISM, DPDP Act) or breakthrough is a potential question — keep a live example bank.