Table of Contents : Science & Tech
Introduction : Science & Tech
If you look the UPSC Prelims papers from the last three years(2023-2025), one thing is clear: the “Static” portion of Science is not asked by UPSC. The time of memorizing the parts of a cell or the laws of Newton is over. now , the Union Public Service Commission is more focus on Applications base questions than traditional pattern. They want to know if you understand how a Quantum Chip works, why a Reusable Launch Vehicle is a game-changer for India’s economy, and how CRISPR-Cas9 could rewrite the future of medicine.
that means UPSC wants to applied thinking than memorizing.
For many aspirants—especially those from a non-science background—GS Paper 3 feels like an unpredictable mountain. But what if I told you that 90% of the questions come from just 5 specific “Pillars”?
Within this micro-analysis, we are decoding the Science and Technology syllabus and distilling it down to manageable chunks. By mastering these concepts, you are no longer sitting in class studying, you are studying to score.
In this we have to discuss about Space Technology
Space Technology
1.1 Evolution of Launch Vehicles
Only PSLV, GSLV don’t stop there. One has to get an insight into the shift in propulsion:
SSLV – Small Satellite Launch Vehicle, this is an “on-demand” launch capability:
RLV-TD (Reusable Launch Vehicle): Emphasis on the “LEX” (Landing Experiment)
Cryogenic Engines: Understand why the CE-20 engine was the turning point for our heavy-lift capabilities.
| Feature | SSLV | PSLV | GSLV Mk II / LVM3 |
| Full Form | Small Satellite Launch Vehicle | Polar Satellite Launch Vehicle | Geosynchronous Satellite Launch Vehicle |
| Primary Orbit | Low Earth Orbit (LEO) | Sun-Synchronous Polar Orbit (SSPO) | Geosynchronous Transfer Orbit (GTO) |
| Payload (LEO) | ~500 kg | ~3,800 kg | 6,000 kg (Mk II) / 8,000 kg (LVM3) |
| Payload (GTO) | N/A | ~1,425 kg | 2,250 kg (Mk II) / 4,000 kg (LVM3) |
| No. of Stages | 3 (All Solid) + VTM* | 4 (Solid & Liquid alternate) | 3 (Solid, Liquid & Cryogenic) |
| Cryogenic Stage | No | No | Yes (Uppermost stage) |
| Turnaround Time | ~72 hours (Quick) | ~2 months | ~3–4 months |
| Key Use Case | Small/Nano satellites, commercial “on-demand” | Remote sensing, Earth observation, Chandrayaan-1, MOM | Communication satellites, heavy deep-space missions (Chandrayaan-3) |
1.2 The “Big Three” Missions
By the 2026 exam, these three will be the hottest topics in the news:
Gaganyaan: This subject tends to focus on the “HSP”, or Human Spaceflight Programme, and the life-support systems. What is the role of Vyommitra?
Shukrayaan-1: India’s mission to Venus. Why Venus? Emphasize the atmospheric study of the planet.
Chandrayaan-4: The goal of “Sample Return.” Technologically, how does it differ from Chandrayaan-3?
| Feature | Chandrayaan-3 | Gaganyaan | Shukrayaan (VOM) |
| Mission Type | Lunar Lander & Rover | Human Spaceflight | Venus Orbiter |
| Status | Successfully Completed | In Final Testing Phase | Formally Approved |
| Launch Date | July 14, 2023 | Jan 2026 (Uncrewed G1) 2027 (Crewed) | March 29, 2028 |
| Launch Vehicle | LVM3 M4 | Human-Rated LVM3 (HLVM3) | LVM3 (Planned) |
| Target Destination | Lunar South Pole | Low Earth Orbit (400 km) | Venusian Orbit |
| Key Objectives | Soft landing & in-situ scientific study of lunar soil. | Demonstrate safe human travel to space and return. | Study Venusian atmosphere, surface, and subsurface. |
| Key Components | Vikram Lander, Pragyan Rover, Propulsion Module. | Crew Module (CM) & Service Module (SM). | Orbiter with Synthetic Aperture Radar (SAR). |
| Budget (Approx.) | ₹615 Crore | ₹20,193 Crore (Expanded) | ₹1,236 Crore |
1.3 The Privatization of Space (Space 2.0)
The Privatization of Space (Space 2.0)
The UPSC in general is trending ‘Governance in Science.’
IN-SPACe & NSIL: It is a must that you understand the difference between these two. It is a regulatory agency. It is the commercial arm.
| Feature | IN-SPACe | NSIL (NewSpace India Ltd) |
| Full Form | Indian National Space Promotion and Authorisation Centre | NewSpace India Limited |
| Role | Regulator & Promoter | Commercial Arm |
| Nature | Autonomous Nodal Agency (Single-window) | Central Public Sector Undertaking (PSU) |
| Primary Goal | To let private companies (NGEs*) use ISRO facilities and build their own rockets/satellites. | To sell ISRO’s technology, launch services, and satellites to global and domestic customers. |
| Key Activity | Authorizing private launches (like Skyroot or Agnikul) and sharing ISRO’s labs. | Building PSLV/SSLV rockets through industry and leasing satellite transponders (e.g., GSAT-24). |
| Interactions | Works with Startups and private industries. | Works with Government & Global clients (like OneWeb, Tata Play). |
The Artemis Accords: Why did India agree to this agreement under US leadership? What implications does this have regarding our ties with Russia in matters of the International Space Station?
A set of non-binding principles and best practices for the civil exploration and sustainable use of the Moon, Mars, comets, and asteroids.
Genesis: Launched in 2020 by NASA and the U.S. State Department.
Foundation: Built upon the 1967 Outer Space Treaty (OST), the “constitution” of space.
Latest Status (2025): * India: Signed on June 21, 2023 (27th signatory).
- Global Footprint: As of late 2025, there are 60 signatories (Latvia joined in Nov 2025). Other recent 2025 additions include Hungary, Malaysia, and the Philippines.
1.4 Deep Space & Observatories
Aditya-L1:Lagrange points (L1 to L5) are something you must be familiar with. Why is it that the ‘parking spot’
Aditya-L1 is India’s first dedicated space-based observatory to study the Sun. The ISRO launched it on September 2, 2023. Currently, it sits at a special “parking spot” in space, the Lagrange Point 1 (L1).
| Feature | Details |
| Launch Date | September 2, 2023 |
| Launch Vehicle | PSLV-C57 (XL variant) |
| Current Status | Operational (Entered Halo Orbit on Jan 6, 2024) |
| Location | Halo Orbit around L1 Point (1.5 million km from Earth) |
| Mission Life | ~5 Years (Expected) |
| No. of Payloads | 7 (4 Remote Sensing + 3 In-situ) |
XPoSat: Discuss “X-Ray Polarimetry” and its importance in Black Hole research. Aspirant Tip: “Whenever you study Space Tech, make a small drawing of the `Orbits’ (LEO, MEO, & GEO). This will help you understand why a communication satellite needs to go higher compared to a remote sensing satellite.”
PYQs MAINS
- 2023: Discuss the main tasks of Chandrayaan-3 that were not achieved by earlier missions. List the countries that have achieved soft landings. (Focus: Soft landing on the South Pole).
- 2016/2017: Discuss the utility of the Mars Orbiter Mission (MOM) for India and why India has ventured into unmanned missions but not yet manned missions. (Note: This was before the formal Gaganyaan announcement).
- 2022: What is India’s plan to have its own Space Station and how will it benefit our space programme? (Focus: Microgravity research, 2035 target).
- 2015: Discuss the advantages of the IRNSS (NavIC) program employing just seven satellites. (Focus: Regional autonomy from GPS).
- 2022: Discuss the unique features of the James Webb Space Telescope (JWST) compared to its predecessors (Hubble). (Focus: Infrared capability, L2 point).
PYQs prelims + Practice Quiz
Q1.With reference to the Indian Regional Navigation Satellite System (IRNSS), consider the following statements:
- IRNSS has a constellation of seven satellites.
- It covers the whole of India and about 5000 sq. km beyond its borders.
- India will have its own satellite navigation system with full global coverage by 2024. Which of the statements given above is/are correct?
A. 1 only
B. None of the above
C. 1 and 2 only
D. 2 and 3 only
ANS : A. 1 only
Q2.Which of the following launch vehicles is primarily used by ISRO to launch the ‘Gaganyaan’ mission’s crew module?
A. SSLV
B. GSLV Mk III (LVM3)
C. PSLV-C37
D.SSLV
ANS : B. GSLV Mk III (LVM3)
Q3. What is the primary objective of ISRO’s ‘Aditya-L1’ mission?
A. To explore the atmosphere of Venus
B. To study the solar corona and solar winds
C. To study the lunar south pole
D. To search for water on Mars
ANS : B. To study the solar corona and solar winds
Q4. Consider the following statements regarding ‘Bhuvan’, the geoportal of ISRO:
- It allows users to explore a 2D and 3D representation of the surface of the Earth.
- It provides services related to disaster management and agriculture. Which of the statements given above is/are correct?
A.1 only
B. Both 1 and 2
C. Neither 1 nor 2
D. 2 only
ANS : B. Both 1 and 2
Q5.In the context of space technology, what does the term ‘Kessler Syndrome’ refer to?
A. The degradation of satellite electronics due to solar flares
B. The failure of a rocket engine during the cryogenic stage
C. A cascade of collisions among objects in Low Earth Orbit (LEO)
D. The psychological effect of long-duration spaceflight on astronauts
ANS C. A cascade of collisions among objects in Low Earth Orbit (LEO)