Yes. Science & Technology is a dedicated section in the UPSC Prelims syllabus and also appears as part of GS Paper III in the Mains examination. In recent years, UPSC has consistently asked 10–15 questions from S&T in Prelims. Topics like biotechnology, space missions, AI, and defence technology are especially high-value areas for both Prelims and Mains.

For UPSC 2026, the highest-priority S&T topics include: Biotechnology (CRISPR, GM Crops, CAR-T Cell Therapy), Space Technology (Gaganyaan, Chandrayaan-3, NISAR), Emerging Technologies (AI, Quantum Computing, Blockchain), Defence Technology (BrahMos, S-400, Nuclear Triad), Nuclear Technology (SMRs, ITER), and Clean Technology (Green Hydrogen, Solid State Batteries). Current affairs linkages to these topics are equally important.

Start with NCERT Science books (Class 6–10) for foundational concepts. Then move to topic-specific notes like those provided by Legacy IAS. Focus on understanding concepts rather than rote memorisation. Link S&T topics to current affairs — for example, when a new ISRO mission launches or a new technology is deployed in defence, that becomes immediately relevant for the exam. Revise regularly using PYQ analysis.

The best sources include: NCERT Science (Class 6–10) for fundamentals; Legacy IAS topic-wise notes (linked above) for UPSC-oriented coverage; PIB (Press Information Bureau) and ISRO/DRDO official websites for current affairs; and science journals like Down To Earth and The Hindu's Science section for application-level understanding. Avoid reading too many sources — depth over breadth is the key.

Historically, UPSC Prelims GS Paper 1 contains around 10–18 questions directly or indirectly from Science and Technology. This includes questions on recent developments (like new satellite launches, new drugs, or defence systems), conceptual questions (like how mRNA vaccines work or what is quantum entanglement), and application-based questions. The share has been increasing in recent years, making it a high-return section.

PSLV (Polar Satellite Launch Vehicle) is ISRO's workhorse for launching satellites into polar and sun-synchronous orbits — it is highly reliable and has been used for Chandrayaan-1 and Mangalyaan. GSLV (Geosynchronous Satellite Launch Vehicle) uses an indigenous cryogenic engine and is used for communication satellites. LVM3 (formerly GSLV Mk III) is ISRO's heaviest launch vehicle with higher payload capacity, used for Chandrayaan-3 and the OneWeb commercial mission. Each has different payload capacities and target orbits.

Yes, biotechnology is explicitly mentioned in the UPSC GS Paper III syllabus under "Science and Technology — developments and their applications and effects in everyday life." Key areas include: genetic engineering (CRISPR), genome sequencing, GM crops (BT Cotton, GM Mustard), CAR-T cell therapy, gene therapy, and biosimilars. UPSC often asks questions that link biotechnology to ethics, food security, and public health policy — so understanding both the science and its societal implications is important.