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Space, Defence and Technology PYQs – Static GK, SSC & Railway

245 Space, Defence and Technology (Static GK) questions asked in recent SSC and Railway exams, newest first, with exam, date & shift, answers and solutions.

📚 245 questionsSSC 206 · Railway 39
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SSC Stenographer 2026 – 15 September 2026 Shift 2 · International space missions and agencies

Q1. Why is Skylab considered a pioneering milestone in the history of space stations, and what critical lessons did it offer for the development of long-duration space habitats?

  1. (a) Skylab was the first international space station launched by NASA and ESA, equipped with artificial gravity and lunar landing capabilities.
  2. (b) Skylab was the first modular space telescope in low Earth orbit used to detect dark matter and black holes using X-ray astronomy.
  3. (c) Skylab was the United States' first space station that demonstrated the feasibility of long-duration human presence in space and helped study the effects of microgravity on humans, despite suffering damage during launch.
  4. (d) Skylab was a robotic Mars outpost that served as a base for interplanetary navigation and surface sample return missions.
Answer & solution

Answer: (c) Skylab was the United States' first space station that demonstrated the feasibility of long-duration human presence in space and helped study the effects of microgravity on humans, despite suffering damage during launch.

Answer: Option 3 — Skylab was the United States' first space station, proving long-duration human presence in space and the effects of microgravity, despite damage during launch.
Skylab, launched on 14 May 1973, lost its micrometeoroid shield and one solar panel during launch; the first crew repaired it in orbit with a parasol sunshade.
Its three crews then lived aboard for 28, 59 and 84 days, the first long-duration medical data on humans in microgravity.
Revision note — Skylab and the space stations
• Skylab was launched on 14 May 1973 on the last Saturn V rocket, built from a converted S-IVB stage.
• It re-entered on 11 July 1979, scattering debris over the Indian Ocean and Western Australia.
• Three crewed missions (Skylab 2, 3 and 4) spent a total of about 171 days aboard; the 84-day Skylab 4 stay was the record until Salyut 6.
• The world's first space station was the Soviet Salyut 1 (April 1971); the first modular station was Mir (1986–2001).
• The International Space Station has been assembled since 20 November 1998 (Zarya module); it orbits at about 400 km, inclined at 51.6°, circling the Earth about 16 times a day.
• China's Tiangong station was completed in 2022; India's Bharatiya Antariksh Station is planned with 5 modules, the first (BAS-1) targeted for 2028 and the full station by 2035.
• Skylab carried the Apollo Telescope Mount, which produced the first detailed X-ray and ultraviolet images of the Sun from orbit.
Do not mix these up
• Skylab vs Salyut 1 — Salyut 1 (USSR, 1971) was the first space station of all; Skylab (1973) was the first American one.
• Skylab vs Hubble — Skylab was a crewed station; Hubble (1990) is an uncrewed telescope and was never a habitat.
Also asked from this topic: the year the International Space Station was launched (1998); its orbital altitude (about 400 km); the number of modules planned for Bharatiya Antariksh Station (5).
SSC Stenographer 2026 – 15 September 2026 Shift 2 · Launch vehicles and satellites

Q2. In the context of India's development of Reusable Launch Vehicle (RLV) technology, which of the following statements best explains the long-term advantages and challenges associated with such systems in comparison to conventional expendable launch vehicles?

  1. (a) RLVs eliminate the need for onboard cryogenic stages, making them more suitable for deep-space interplanetary missions.
  2. (b) RLVs significantly reduce launch costs by enabling partial or full recovery and reuse of stages, but face challenges in thermal protection, hypersonic aerodynamics, and autonomous landing precision.
  3. (c) RLVs use air-breathing propulsion systems for orbital injection, removing dependence on ground-based launch pads.
  4. (d) Unlike expendable launch vehicles, RLVs require no telemetry tracking systems as they operate exclusively in suborbital trajectories.
Answer & solution

Answer: (b) RLVs significantly reduce launch costs by enabling partial or full recovery and reuse of stages, but face challenges in thermal protection, hypersonic aerodynamics, and autonomous landing precision.

Answer: Option 2 — RLVs significantly reduce launch costs by enabling partial or full recovery and reuse of stages, but face challenges in thermal protection, hypersonic aerodynamics and autonomous landing precision.
The whole case for an RLV is cost: an expendable rocket is thrown away after one flight, while a reusable stage flies again.
The price is engineering difficulty — surviving re-entry heating, flying stably at hypersonic speed and landing autonomously on a runway or pad.
Revision note — ISRO's Reusable Launch Vehicle programme
• RLV-TD (Reusable Launch Vehicle – Technology Demonstrator) is ISRO's winged vehicle.
• Its first flight, HEX-01 (hypersonic flight experiment), took off from Sriharikota on 23 May 2016 and splashed down in the Bay of Bengal.
• RLV-LEX-01 (2 April 2023) at the Aeronautical Test Range, Chitradurga, Karnataka: the vehicle was released from an IAF Chinook helicopter at 4.5 km and landed autonomously on the runway.
• LEX-02 (22 March 2024) and LEX-03 (23 June 2024) repeated the landing from higher release points and cross-wind conditions; the vehicle is named Pushpak.
• The next step is the Orbital Re-entry Vehicle (ORV) experiment, in which a winged body returns from orbit and lands.
• The SpaceX Falcon 9 first landed and recovered its first stage in December 2015, cutting launch costs sharply; NASA's Space Shuttle (1981–2011) was the first partly reusable launcher.
• Cost of access to space was estimated at roughly US$ 20,000 per kg with expendable rockets; ISRO aims to cut it to about one-tenth with reusability.
Do not mix these up
• RLV-TD vs RLV-LEX — RLV-TD is the vehicle programme; LEX is the series of landing experiments flown with it.
• Reusable vs air-breathing — an RLV still uses rocket engines; ISRO's scramjet (air-breathing) test of August 2016 was a separate programme.
Also asked from this topic: the name of India's reusable launch vehicle (RLV-TD); the landing missions that put India among RLV-capable nations (RLV-LEX); the main purpose of RLVs (lower launch cost).
SSC Stenographer 2026 – 12 September 2026 Shift 1 · International space missions and agencies

Q3. Which of the following statements about the James Webb Space Telescope (JWST) is incorrect?

  1. (a) JWST operates primarily in the infrared spectrum, enabling it to observe distant, redshifted galaxies and early universe phenomena.
  2. (b) It is positioned at the Earth-Sun L2 Lagrange point, allowing stable thermal conditions and minimal Earth shadow interference.
  3. (c) JWST features a segmented primary mirror made of beryllium coated with gold, which unfolds after launch to achieve its full aperture.
  4. (d) Unlike the Hubble Space Telescope, JWST is designed for continuous optical wavelength observation with minimal infrared capability.
Answer & solution

Answer: (d) Unlike the Hubble Space Telescope, JWST is designed for continuous optical wavelength observation with minimal infrared capability.

Answer: Option 4 — Unlike the Hubble Space Telescope, JWST is designed for continuous optical wavelength observation with minimal infrared capability.
The question asks for the incorrect statement.
JWST is above all an infrared telescope (about 0.6 to 28 micrometres); it is Hubble that works mainly in visible and ultraviolet light.
Options 1, 2 and 3 — infrared, the L2 point and the gold-coated beryllium mirror — are all true.
Revision note — James Webb Space Telescope
• Launched on 25 December 2021 on an Ariane 5 rocket from Kourou, French Guiana; a joint project of NASA, ESA and the Canadian Space Agency.
• Orbits the Sun–Earth L2 Lagrange point, about 1.5 million km from Earth on the side away from the Sun, so the Sun, Earth and Moon stay behind its sunshield.
• Primary mirror 6.5 m across, made of 18 hexagonal beryllium segments coated with gold; a five-layer sunshield the size of a tennis court keeps it below −220 °C.
• Instruments: NIRCam, NIRSpec, MIRI and FGS/NIRISS; infrared lets it see light from the first galaxies, which the expanding universe has redshifted out of the visible range.
• Named after James E. Webb, NASA administrator during the Apollo era; first science images were released on 12 July 2022.
• Hubble (launched 1990) orbits Earth at about 540 km, has a 2.4 m mirror and observes mainly ultraviolet, visible and near-infrared light.
Do not mix these up
• L1 vs L2 — Aditya-L1 sits at L1, between the Sun and Earth, for an unbroken view of the Sun; JWST sits at L2, beyond Earth, for a cold, dark sky.
• JWST vs Hubble — Webb is a successor, not a replacement: infrared versus visible, and it is too far away to be serviced by astronauts as Hubble was.
Also asked from this topic: the wavelength region and position of JWST (near- and mid-infrared, at Sun–Earth L2); another name for Lagrange points (libration points); the Lagrange point of Aditya-L1 (L1).
SSC Stenographer 2026 – 12 September 2026 Shift 1 · Indian space missions

Q4. Which of the following accurately reflects the long-term strategic vision and technological challenges associated with India's proposed Bharatiya Antariksh Station, and how it differs from existing international space stations?

  1. (a) The Bharatiya Antariksh Station will be a joint India-Russia project focused on geostationary orbit operations, equipped for planetary defense.
  2. (b) Unlike the International Space Station (ISS), the Bharatiya Antariksh Station will be modular, entirely domestically built, and operate in low Earth orbit for scientific research and long-duration crewed missions.
  3. (c) The Bharatiya Antariksh Station will orbit the Moon to serve as a gateway for India's future lunar mining and habitation missions.
  4. (d) It is India's first robotic Mars outpost, intended for autonomous sample return missions and artificial gravity experiments.
Answer & solution

Answer: (b) Unlike the International Space Station (ISS), the Bharatiya Antariksh Station will be modular, entirely domestically built, and operate in low Earth orbit for scientific research and long-duration crewed missions.

Answer: Option 2 — Unlike the International Space Station (ISS), the Bharatiya Antariksh Station will be modular, entirely domestically built, and operate in low Earth orbit for scientific research and long-duration crewed missions.
The Bharatiya Antariksh Station (BAS) is ISRO's indigenous, modular space station planned for low Earth orbit at roughly 400 to 450 km.
The ISS, by contrast, is a multinational station built by five agencies; BAS is planned neither for geostationary orbit nor for lunar orbit.
Revision note — Bharatiya Antariksh Station
• Announced as a goal in October 2023, when the Prime Minister set the targets of a space station by 2035 and an Indian on the Moon by 2040 (India's Space Vision 2047).
• The Union Cabinet approved the first module, BAS-1, on 18 September 2024 as part of the expanded Gaganyaan programme, taking its total outlay to about ₹20,193 crore.
• BAS-1 is scheduled for launch in 2028; the full station of five modules is to be operational by 2035.
• A scale model of BAS-1 was unveiled by ISRO in August 2025; long-duration stays will need the Next Generation Launch Vehicle (NGLV), approved in September 2024.
• The station will host microgravity research, long-duration crewed stays and, later, space tourism, and will build on the Gaganyaan crewed flights.
• Existing stations: the ISS (first module 1998; NASA, Roscosmos, ESA, JAXA and CSA) and China's Tiangong (core module 2021).
Do not mix these up
• Bharatiya Antariksh Station vs Gaganyaan — Gaganyaan is the crewed spacecraft programme; BAS is the permanent station those flights will later serve.
• Space station vs Lunar Gateway — NASA's Gateway was planned to orbit the Moon (NASA paused work on it in March 2026); BAS, Tiangong and the ISS are all in low Earth orbit.
Also asked from this topic: the launch year of the first BAS module (2028); the target years for the station and an Indian Moon landing (2035 and 2040); the number of modules planned (five).
SSC Stenographer 2026 – 12 September 2026 Shift 1 · Indian space missions

Q5. What distinguishes the LUPEX (Lunar Polar Exploration) mission from previous lunar missions, and what are its strategic and scientific implications for future interplanetary exploration?

  1. (a) LUPEX is a NASA-led mission aiming to launch a solar-powered telescope from the Moon's far side to observe deep-space galaxies, with challenges related to Earth visibility.
  2. (b) LUPEX will deploy a rover near the lunar equator to conduct high-resolution mineral mapping using X-ray fluorescence technology, focused on past volcanic activity.
  3. (c) LUPEX is a joint ISRO–JAXA mission targeting the lunar south pole to explore permanently shadowed regions for water ice, using a lander-rover system, contributing to potential crewed lunar bases and future Mars missions.
  4. (d) LUPEX is India's first space-based solar observatory placed in lunar orbit to measure electromagnetic interference from Earth's magnetosphere during eclipses.
Answer & solution

Answer: (c) LUPEX is a joint ISRO–JAXA mission targeting the lunar south pole to explore permanently shadowed regions for water ice, using a lander-rover system, contributing to potential crewed lunar bases and future Mars missions.

Answer: Option 3 — LUPEX is a joint ISRO–JAXA mission targeting the lunar south pole to explore permanently shadowed regions for water ice, using a lander-rover system, contributing to potential crewed lunar bases and future Mars missions.
LUPEX is the India–Japan lunar mission in which ISRO builds the lander and JAXA the rover and the H3 launch rocket.
Its target is the quantity and quality of water ice in the permanently shadowed craters of the south pole — the resource on which any future Moon base depends.
Revision note — LUPEX / Chandrayaan-5
• A joint ISRO–JAXA mission, approved by the Government of India in March 2025 as Chandrayaan-5; launch is planned around 2028–29.
• JAXA provides the H3-24L launch vehicle and a rover of about 350 kg; ISRO provides the lander, with instruments also from NASA and ESA.
• The rover will drill and sample soil in permanently shadowed regions near the south pole and is designed to survive the long lunar night.
• Builds on Chandrayaan-3, which made India the first nation to soft-land near the lunar south pole on 23 August 2023 at Shiv Shakti Point.
• Chandrayaan-4, approved in September 2024, is a sample-return mission planned for around 2027; Chandrayaan-1 (2008) first confirmed water molecules on the Moon.
• These missions feed the 2040 target of landing an Indian on the Moon.
Do not mix these up
• Chandrayaan-4 vs Chandrayaan-5 — the fourth brings lunar samples back to Earth; the fifth (LUPEX) studies water ice in place with a Japanese rover.
• LUPEX vs Aditya-L1 — Aditya-L1 is India's solar observatory at L1; LUPEX is a lunar surface mission.
Also asked from this topic: the primary objective of LUPEX (to study the quantity and quality of water on the Moon's polar region); the launch vehicle for Chandrayaan-5 (Japan's H3-24L).
SSC Stenographer 2026 – 12 September 2026 Shift 1 · Indian space missions

Q6. In what ways does ASTROSAT's multi-wavelength observation capability distinguish it from conventional space telescopes, and what scientific advantages does this offer for high-energy astrophysics and cosmology research?

  1. (a) ASTROSAT focuses only on visible and infrared wavelengths to study Earth's magnetosphere and atmospheric chemistry, unlike other telescopes that observe deep-space objects.
  2. (b) ASTROSAT's design allows simultaneous observation of celestial sources in UV, optical, and X-ray bands, enabling real-time correlation of high-energy phenomena like black hole activity, X-ray binaries, and gamma-ray bursts.
  3. (c) ASTROSAT is designed to detect gravitational waves in coordination with LIGO by using radio-frequency bursts and radar echo timing from pulsars.
  4. (d) ASTROSAT's primary goal is to map exoplanets using Doppler spectroscopy from a Sun-synchronous polar orbit.
Answer & solution

Answer: (b) ASTROSAT's design allows simultaneous observation of celestial sources in UV, optical, and X-ray bands, enabling real-time correlation of high-energy phenomena like black hole activity, X-ray binaries, and gamma-ray bursts.

Answer: Option 2 — ASTROSAT's design allows simultaneous observation of celestial sources in UV, optical, and X-ray bands, enabling real-time correlation of high-energy phenomena like black hole activity, X-ray binaries, and gamma-ray bursts.
AstroSat is India's first dedicated multi-wavelength space observatory: its five instruments watch the same object at the same time in ultraviolet, visible and X-ray light.
Most telescopes cover one band, so they must wait for another observatory to fill in the rest — AstroSat sees a flaring black hole or X-ray binary across the spectrum at once.
Revision note — AstroSat
• Launched on 28 September 2015 by PSLV-C30 from Sriharikota into a 650 km near-equatorial orbit; mass about 1,513 kg.
• Five payloads: UVIT (ultraviolet imaging), SXT (soft X-ray), LAXPC (large-area X-ray proportional counters), CZTI (hard X-ray imager) and SSM (scanning sky monitor).
• Landmark results: UVIT detected extreme-ultraviolet light from the galaxy AUDFs01, and CZTI measured X-ray polarisation of the Crab pulsar and nebula.
• Studies black holes, neutron stars, X-ray binaries and gamma-ray bursts; data are handled by the ISSDC at Bengaluru and the science is led by IUCAA, TIFR and IIA.
• India's second astronomy satellite is XPoSat, launched on 1 January 2024 — the country's first X-ray polarimetry mission, with POLIX and XSPECT.
• Aditya-L1 (2 September 2023) is the solar observatory; it looks at the Sun, not at deep-space sources.
Do not mix these up
• AstroSat vs XPoSat — AstroSat observes many wavelengths at once; XPoSat measures the polarisation of X-rays from about 50 bright sources.
• AstroSat vs Hubble — Hubble is a single-mirror optical–UV telescope; AstroSat is a suite of five instruments spanning UV to hard X-rays.
Also asked from this topic: the unique feature of AstroSat (simultaneous multi-wavelength observation); its discoveries (UV emission from a remote galaxy; X-ray polarisation of a supernova remnant); its launch (28 September 2015).
SSC Stenographer 2026 – 12 September 2026 Shift 2 · Launch vehicles and satellites

Q7. Which of the following best characterizes the strategic advantages and technical challenges of space-based surveillance systems, particularly in the context of national security?

  1. (a) They provide persistent global coverage and real-time tactical data without the need for ground-based infrastructure, but are limited by high latency and atmospheric attenuation
  2. (b) They offer wide-area, day-night, and all-weather monitoring capabilities, but face limitations in coverage due to Earth's curvature and terrain masking.
  3. (c) They enable high-resolution imagery, early warning, and missile tracking, but are vulnerable to anti-satellite (ASAT) weapons and require complex orbital coordination.
  4. (d) They primarily rely on passive sonar and radio triangulation methods to detect ground targets, which reduces their utility in desert and mountainous environments.
Answer & solution

Answer: (c) They enable high-resolution imagery, early warning, and missile tracking, but are vulnerable to anti-satellite (ASAT) weapons and require complex orbital coordination.

Answer: Option 3 — They enable high-resolution imagery, early warning, and missile tracking, but are vulnerable to anti-satellite (ASAT) weapons and require complex orbital coordination.
Surveillance satellites give high-resolution optical and radar imagery, infrared early warning of missile launches and tracking of missiles in flight.
Their weak points are exactly what the option names: they can be destroyed or jammed by anti-satellite weapons,
and a useful constellation needs many satellites in carefully planned orbits so that a target is revisited often enough.
Earth's curvature and terrain masking limit ground radars, not satellites; sonar works under water; and every satellite still needs ground stations to downlink its data.
Revision note — Space-based surveillance and India
• Cartosat satellites give high-resolution optical images (Cartosat-3, 2019, about 25 cm resolution); RISAT satellites carry synthetic aperture radar for day-night, all-weather imaging.
• EMISAT (April 2019), built with DRDO, is India's electronic-intelligence satellite; GSAT-7 (Rukmini) serves the Navy and GSAT-7A the Air Force.
• Mission Shakti, 27 March 2019 — India's first ASAT test, in which a DRDO interceptor destroyed Microsat-R in low Earth orbit, making India the fourth ASAT power after the USA, Russia and China.
• The Space Based Surveillance (SBS-3) programme approved in October 2024 will put 52 satellites in orbit for defence, run through the Defence Space Agency (2019).
• NETRA is ISRO's network for tracking space debris; the start-up Digantara launched SCOT, a commercial space-surveillance satellite, in January 2025 on SpaceX's Transporter-12 mission.
• Internationally, the US SBIRS satellites detect missile launches by their infrared plume; GPS, NavIC and Galileo give the positioning that guided weapons depend on.
Do not mix these up
• Optical vs radar imaging satellites — optical (Cartosat) needs daylight and clear sky; radar (RISAT) images through cloud and at night.
• ASAT weapon vs ballistic missile defence — Mission Shakti used a BMD interceptor, but its target was a satellite in orbit, not an incoming missile.
Also asked from this topic: India's first anti-satellite missile test (Mission Shakti, 2019); the ISRO satellite giving high-resolution images for agriculture and forestry (Cartosat-3).
SSC Stenographer 2026 – 12 September 2026 Shift 2 · International space missions and agencies

Q8. Which key discovery made by NASA's MAVEN mission has significantly advanced our understanding of how Mars lost much of its atmosphere?

  1. (a) Detection of liquid water beneath the Martian surface
  2. (b) Measurement of the rate at which solar wind strips away Mars' atmosphere
  3. (c) Discovery of methane plumes indicating active geology
  4. (d) Mapping of Martian polar ice caps' seasonal changes
Answer & solution

Answer: (b) Measurement of the rate at which solar wind strips away Mars' atmosphere

Answer: Option 2 — Measurement of the rate at which solar wind strips away Mars' atmosphere
MAVEN (Mars Atmosphere and Volatile EvolutioN) measured, in 2015, that the solar wind strips about 100 grams of gas per second from the top of the Martian atmosphere.
The loss jumps 10 to 20 times during solar storms.
Because Mars has no global magnetic field to deflect the solar wind, this slow leak over billions of years turned a thick, wet atmosphere into today's thin one.
Revision note — MAVEN and the exploration of Mars
• MAVEN was launched on 18 November 2013 on an Atlas V and entered Mars orbit on 22 September 2014 (21 September by US clocks) — two days before India's Mangalyaan arrived on 24 September 2014.
• It is an orbiter only; it studies the upper atmosphere and ionosphere and also acts as a communications relay for NASA's rovers.
• Mangalyaan (Mars Orbiter Mission), launched on 5 November 2013 by PSLV-C25, made India the first country to reach Mars orbit on its maiden attempt; it carried a Methane Sensor for Mars.
• The other options belong to other missions: ESA's Mars Express radar reported a liquid-water lake under the south polar cap in 2018, and methane was detected by the Curiosity rover.
• NASA's rovers: Sojourner (1997), Spirit and Opportunity (2004), Curiosity (2012) and Perseverance (2021), which carried the Ingenuity helicopter.
• Mars facts: two moons, Phobos and Deimos; the Red Planet from iron oxide dust; Olympus Mons, the largest volcano in the solar system; a day of about 24 h 37 min.
Do not mix these up
• MAVEN vs Mangalyaan — both reached Mars in September 2014; MAVEN is NASA's atmosphere-loss mission, Mangalyaan is ISRO's technology-demonstration orbiter.
• Solar wind vs solar flare — the solar wind is the continuous stream of charged particles from the Sun; a flare is a sudden burst of radiation that makes the stripping spike.
Also asked from this topic: India's first interplanetary mission (Mangalyaan); its launch year (2013; Mars orbit on 24 September 2014); the Aditya-L1 payload that studies the solar wind (ASPEX).
SSC Stenographer 2026 – 12 September 2026 Shift 2 · International space missions and agencies

Q9. NASA's Dragonfly mission to Titan will primarily use which of the following capabilities to explore Titan's surface and study its prebiotic chemistry?

  1. (a) A rotorcraft lander capable of flying multiple locations to analyze surface composition
  2. (b) A stationary rover equipped with a drill to collect deep ice core samples
  3. (c) An orbiter with high-resolution radar to map Titan's methane lakes
  4. (d) A balloon that floats in Titan's atmosphere to study weather patterns
Answer & solution

Answer: (a) A rotorcraft lander capable of flying multiple locations to analyze surface composition

Answer: Option 1 — A rotorcraft lander capable of flying multiple locations to analyze surface composition
Dragonfly is a nuclear-powered rotorcraft — an eight-rotor drone the size of a car.
Titan's dense atmosphere and low gravity make flight easy, so it will hop between dozens of sites, sampling the organic-rich surface at each stop.
Revision note — Dragonfly and Titan
• Dragonfly is the fourth New Frontiers mission of NASA, selected in June 2019 after New Horizons, Juno and OSIRIS-REx; it is built and managed by the Johns Hopkins Applied Physics Laboratory.
• Launch is planned for July 2028 on a Falcon Heavy, with arrival at Titan in 2034; the landing zone is the Shangri-La dune fields near the Selk impact crater.
• Power comes from a Multi-Mission Radioisotope Thermoelectric Generator (MMRTG), because sunlight at Saturn is too weak for solar panels under Titan's haze.
• Titan is the largest moon of Saturn and the second largest in the Solar System after Jupiter's Ganymede.
• It is the only moon with a thick atmosphere (mostly nitrogen, some methane) and, apart from Earth, the only world with surface liquids — seas of liquid methane and ethane such as Kraken Mare.
• Titan was discovered by Christiaan Huygens in 1655; ESA's Huygens probe, carried by NASA's Cassini, landed on it on 14 January 2005 — the first landing in the outer Solar System.
• Dragonfly's goal is prebiotic chemistry: Titan's surface holds complex organic molecules over a crust of water ice that may hide a subsurface ocean.
Do not mix these up
• Dragonfly vs Europa Clipper — Dragonfly flies on Titan (Saturn) and lands; Europa Clipper, launched in October 2024, only orbits Jupiter and repeatedly flies past Europa.
• Titan vs Ganymede — both are larger than the planet Mercury, but only Titan has a thick atmosphere; Ganymede is the largest moon of all.
Also asked from this topic: the NASA mission that will explore Jupiter's moon Europa (Europa Clipper); the planet whose rings are disappearing as ring rain (Saturn).
SSC Stenographer 2026 – 12 September 2026 Shift 2 · Launch vehicles and satellites

Q10. What was the name of India's first satellite, launched in 1975?

  1. (a) Aryabhata
  2. (b) Bhaskara
  3. (c) Cartosat-1
  4. (d) INSAT-1A
Answer & solution

Answer: (a) Aryabhata

Answer: Option 1 — Aryabhata
Aryabhata, named after the 5th-century astronomer, was launched on 19 April 1975 by a Soviet Kosmos-3M rocket from Kapustin Yar, taking India into the space age.
Bhaskara (1979), INSAT-1A (1982) and Cartosat-1 (2005) all came later.
Revision note — India's early satellites
• Aryabhata (1975): built by ISRO at Peenya, Bengaluru under Prof. U. R. Rao; weight 360 kg; meant for X-ray astronomy and solar physics.
• A power failure ended its experiments after 5 days; it re-entered the atmosphere in 1992, and it appeared on the ₹2 note.
• Bhaskara-I (1979): India's first experimental earth-observation satellite, also launched by the USSR.
• Rohini RS-1 (18 July 1980): the first satellite launched by an Indian rocket, the SLV-3, from Sriharikota, under A. P. J. Abdul Kalam.
• APPLE (1981): the first Indian communication satellite, launched by the European Ariane; INSAT-1A (1982) was the first of the INSAT series, launched by a US Delta rocket.
• IRS-1A (1988): first operational remote-sensing satellite; Cartosat-1 (2005) the first stereo-imaging cartography satellite, launched by PSLV.
• Aryabhata completed 50 years in April 2025.
Do not mix these up
• Aryabhata vs Rohini RS-1 — Aryabhata was the first Indian satellite (Soviet rocket, 1975); Rohini was the first satellite put up by an Indian launch vehicle (SLV-3, 1980).
• Aryabhata the satellite vs Aryabhata the astronomer — the mathematician (b. 476 CE, author of the Aryabhatiya) lived in the Gupta age.
Also asked from this topic: the year India's first satellite was launched (1975); the number of stages of the SLV-3 rocket (4); the satellite that completed 50 years in April 2025 (Aryabhata).
SSC Stenographer 2026 – 12 September 2026 Shift 2 · Nuclear programme and institutions

Q11. Who is known as the father of the Indian nuclear programme?

  1. (a) C.V. Raman
  2. (b) Meghnad Saha
  3. (c) Homi J. Bhabha
  4. (d) Vikram Sarabhai
Answer & solution

Answer: (c) Homi J. Bhabha

Answer: Option 3 — Homi J. Bhabha
Homi Jehangir Bhabha founded the Tata Institute of Fundamental Research (1945) and was the first chairman of the Atomic Energy Commission (1948), laying out India's three-stage nuclear programme.
Vikram Sarabhai is the father of the Indian space programme, not the nuclear one.
Revision note — Homi J. Bhabha and India's nuclear programme
• Born 30 October 1909 in Bombay; a Cambridge-trained physicist known for Bhabha scattering (electron-positron scattering) and work on cosmic-ray showers.
• Founded TIFR in Mumbai in 1945 with Tata support, and became the first chairman of the Atomic Energy Commission on 10 August 1948.
• He was the first Secretary of the Department of Atomic Energy, set up on 3 August 1954 directly under the Prime Minister.
• The Atomic Energy Establishment, Trombay (1954) was renamed the Bhabha Atomic Research Centre (BARC) in 1967 after his death.
• Apsara (1956) at Trombay was Asia's first nuclear research reactor.
• Bhabha's three-stage programme: stage 1 natural uranium in PHWRs; stage 2 fast breeder reactors using plutonium (the PFBR at Kalpakkam); stage 3 thorium reactors using U-233.
• He died on 24 January 1966 when Air India's Kanchenjunga crashed on Mont Blanc; he received the Padma Bhushan in 1954 and the Adams Prize (1942).
Do not mix these up
• Homi Bhabha vs Vikram Sarabhai — Bhabha is the father of the nuclear programme (AEC, 1948); Sarabhai is the father of the space programme (INCOSPAR, 1962; ISRO, 1969).
• Homi Bhabha vs Raja Ramanna — Bhabha built the institutions; Raja Ramanna led the Pokhran-I test (Smiling Buddha, 18 May 1974), eight years after Bhabha's death.
Also asked from this topic: the new name of the Atomic Energy Establishment, Trombay (BARC, 1967); the date the Department of Atomic Energy was set up (3 August 1954); the site of India's Prototype Fast Breeder Reactor (Kalpakkam).
SSC Stenographer 2026 – 11 September 2026 Shift 1 · Indian space missions

Q12. What is the primary payload of India's XPoSat mission, and what is its main scientific function?

  1. (a) XSPECT – to detect gravitational lensing in gamma-ray bursts
  2. (b) POLIX – to measure polarization in medium energy X-rays
  3. (c) SPOT – to track solar particle events in deep space
  4. (d) PRISM – to study spectral lines from intergalactic gases
Answer & solution

Answer: (b) POLIX – to measure polarization in medium energy X-rays

Answer: Option 2 — POLIX – to measure polarization in medium energy X-rays
POLIX (Polarimeter Instrument in X-rays) is XPoSat's primary payload; it measures the degree and angle of polarisation of X-rays in the 8–30 keV medium-energy band.
XSPECT is the mission's second payload and does spectroscopy and timing, not gravitational lensing.
Revision note — XPoSat (X-ray Polarimeter Satellite)
• Launched on 1 January 2024 by PSLV-C58 from Sriharikota; India's first dedicated X-ray polarimetry mission and only the second in the world after NASA's IXPE (2021).
• POLIX was built by the Raman Research Institute, Bengaluru, and works in the 8–30 keV band.
• XSPECT was built by the U R Rao Satellite Centre and works in the soft 0.8–15 keV band.
• The satellite sits in a low Earth orbit of about 650 km at low inclination, with a planned life of about five years.
• Its targets are black holes, neutron stars, pulsars, magnetars and active galactic nuclei — polarisation reveals the geometry of the emitting region, which a spectrum alone cannot.
• The same flight turned the spent PSLV fourth stage into POEM-3, an orbital experiment platform carrying ten payloads.
Do not mix these up
• POLIX vs XSPECT — POLIX measures polarisation at 8–30 keV; XSPECT measures spectra and timing at 0.8–15 keV.
• XPoSat vs AstroSat — AstroSat (2015) is India's first multi-wavelength space observatory; XPoSat is dedicated to X-ray polarimetry alone.
Also asked from this topic: ISRO's January 2024 mission to study the polarisation of cosmic X-rays (XPoSat); the instrument that measures X-ray polarisation at 8–30 keV (POLIX).
SSC Stenographer 2026 – 11 September 2026 Shift 1 · Indian space missions

Q13. Which mission observes solar activity impacting Earth's space weather?

  1. (a) Astrosat
  2. (b) Bhaskar-III
  3. (c) Aditya-L1
  4. (d) RISAT-2
Answer & solution

Answer: (c) Aditya-L1

Answer: Option 3 — Aditya-L1
Aditya-L1 is India's first dedicated solar mission, parked at the Sun–Earth Lagrange point L1 to watch the Sun without interruption.
Tracking the flares, coronal mass ejections and solar wind that drive space weather at the Earth is exactly its job.
Revision note — Aditya-L1
• Launched on 2 September 2023 aboard PSLV-C57; inserted into a halo orbit around Lagrange point L1 on 6 January 2024.
• L1 lies about 1.5 million km from the Earth — roughly 1 per cent of the Earth–Sun distance — and gives a continuous view of the Sun with no eclipses.
• It carries seven payloads: VELC, SUIT, SoLEXS, HEL1OS, ASPEX, PAPA and a magnetometer.
• VELC (Visible Emission Line Coronagraph) is the primary payload, built by the Indian Institute of Astrophysics; ASPEX studies the solar wind; SUIT images the Sun in the ultraviolet.
• Its main scientific target is the corona, the Sun's outermost layer, along with the photosphere and chromosphere and the puzzle of coronal heating.
• The distractors: AstroSat (2015) is a multi-wavelength observatory and RISAT satellites are radar imaging Earth-observation craft.
• Bhaskar-1 (1979) and Bhaskar-2 (1981) were early experimental remote-sensing satellites — there is no Bhaskar-III.
Do not mix these up
• Aditya-L1 vs AstroSat — Aditya-L1 observes only the Sun, from L1; AstroSat observes many kinds of cosmic sources across wavebands from low Earth orbit.
• Lagrange point L1 vs geostationary orbit — L1 is 1.5 million km away where the two gravities balance; a geostationary orbit is only 35,786 km above the equator.
Also asked from this topic: the part of the Sun Aditya-L1 studies (the corona); the kind of point it orbits (a Lagrangian point, L1); the payload that monitors the solar wind (ASPEX).
SSC Stenographer 2026 – 11 September 2026 Shift 1 · Nuclear programme and institutions

Q14. In which Indian city is the Bhabha Atomic Research Centre located?

  1. (a) Chennai
  2. (b) Mumbai
  3. (c) Hyderabad
  4. (d) Kolkata
Answer & solution

Answer: (b) Mumbai

Answer: Option 2 — Mumbai
The Bhabha Atomic Research Centre (BARC) stands at Trombay in Mumbai, Maharashtra.
It began in 1954 as the Atomic Energy Establishment, Trombay and was renamed after Homi Jehangir Bhabha in 1967.
Revision note — India's nuclear establishment
• BARC, Trombay, Mumbai — set up 3 January 1954 as the Atomic Energy Establishment, Trombay; renamed Bhabha Atomic Research Centre in 1967 after Bhabha's death in an air crash in 1966.
• Homi Jehangir Bhabha, the father of India's nuclear programme, was first chairman of the Atomic Energy Commission (1948).
• The Department of Atomic Energy, created in 1954, reports directly to the Prime Minister.
• Research reactors at Trombay: Apsara (1956), Asia's first research reactor; Cirus (1960); Dhruva (1985); Apsara-U went critical in September 2018 on indigenous low-enriched uranium fuel.
• India's first nuclear test, Pokhran-I, "Smiling Buddha", 18 May 1974, used plutonium from Cirus; Pokhran-II followed on 11 and 13 May 1998.
• Homi Bhabha's three-stage nuclear programme: stage 1 pressurised heavy water reactors on natural uranium, stage 2 fast breeder reactors on plutonium, stage 3 thorium reactors.
• Stage 3 rests on India's large reserves of thorium in the monazite sands of Kerala.
• Other centres: Indira Gandhi Centre for Atomic Research, Kalpakkam; Variable Energy Cyclotron Centre, Kolkata; Nuclear Fuel Complex, Hyderabad.
• Tarapur, Maharashtra (1969) was India's first nuclear power plant; Kudankulam, Tamil Nadu is the largest, built with Russian help.
Do not mix these up
• BARC (Mumbai) vs IGCAR (Kalpakkam) — BARC is the general nuclear research centre; IGCAR leads the fast breeder reactor programme, stage 2 of the three-stage plan.
• Atomic Energy Commission vs Department of Atomic Energy — the AEC (1948) is the policy body; the DAE (1954) is the executive department that runs the establishments.
Also asked from this topic: the new name of the Atomic Energy Establishment, Trombay (Bhabha Atomic Research Centre, 1967); the BARC reactor that first went critical on LEU fuel (Apsara-U).
SSC Stenographer 2026 – 10 September 2026 Shift 1 · Indian space missions

Q15. What does the magnetometer onboard Aditya-L1 satellite primarily measure in space?

  1. (a) Solar radiation pressure
  2. (b) Interplanetary magnetic field strength and direction
  3. (c) Cosmic ray intensity
  4. (d) Solar plasma temperature
Answer & solution

Answer: (b) Interplanetary magnetic field strength and direction

Answer: Option 2 — Interplanetary magnetic field strength and direction
The Magnetometer (MAG) payload measures the interplanetary magnetic field at the L1 point.
It records both the strength and the direction of that field, so changes carried by the solar wind can be tracked.
Revision note — Aditya-L1
• Aditya-L1 is India's first dedicated solar mission, launched by ISRO on 2 September 2023 aboard PSLV-C57.
• It was inserted into its final orbit on 6 January 2024 — a halo orbit around the Sun-Earth Lagrange point L1.
• L1 lies about 15 lakh km from the Earth, roughly 1 per cent of the Earth-Sun distance, and lets the Sun be watched without eclipse or occultation.
• It carries seven payloads: VELC (the primary one, a coronagraph), SUIT, SoLEXS, HEL1OS, ASPEX, PAPA and the Magnetometer (MAG).
• Four payloads observe the Sun directly and three study particles and fields in situ at L1.
• Its targets are the corona and the coronal heating problem, coronal mass ejections, solar flares, the solar wind and space weather.
• A two-body system has five Lagrange points (L1 to L5); L1 lies between the Sun and the Earth.
Do not mix these up
• MAG vs ASPEX — the magnetometer measures the interplanetary magnetic field; ASPEX measures the solar wind's particles, its protons and heavier ions.
• Aditya-L1 vs XPoSat — Aditya-L1 studies the Sun; XPoSat, launched on 1 January 2024, carries POLIX to study X-ray polarisation.
Also asked from this topic: the part of the Sun Aditya-L1 studies (the corona); the payload monitoring solar wind at L1 (ASPEX); the kind of point its halo orbit surrounds (Lagrangian).
SSC Stenographer 2026 – 10 September 2026 Shift 2 · Space tourism and commercial spaceflight

Q16. Which of the following statements regarding the current landscape and challenges of space tourism is incorrect?

  1. (a) Suborbital space tourism flights like those offered by Blue Origin and Virgin Galactic allow passengers to experience microgravity for a few minutes without completing a full orbit around Earth.
  2. (b) Orbital space tourism missions, such as those launched by SpaceX, require significantly higher velocities and pose greater life-support and radiation protection challenges than suborbital flights.
  3. (c) International treaties such as the Outer Space Treaty (1967) clearly define the legal liability and regulatory framework for commercial space tourists in all jurisdictions.
  4. (d) One of the major technological challenges in scaling space tourism is developing reusable spacecraft that can endure multiple launches while ensuring passenger safety and cost-effectiveness.
Answer & solution

Answer: (c) International treaties such as the Outer Space Treaty (1967) clearly define the legal liability and regulatory framework for commercial space tourists in all jurisdictions.

Answer: Option 3 — International treaties such as the Outer Space Treaty (1967) clearly define the legal liability and regulatory framework for commercial space tourists in all jurisdictions.
This is the incorrect statement, and the question asks for it.
The Outer Space Treaty of 1967 binds states, not private tourists.
It says nothing about ticketed passengers or a uniform liability regime, and there is still no single international law on space tourism.
Revision note — Space law and space tourism
• The Outer Space Treaty, 1967 makes space the province of all mankind and bars any state from claiming sovereignty over a celestial body.
• It also forbids weapons of mass destruction in orbit and makes a state internationally responsible for its nationals' space activities.
• Four later treaties follow it — the Rescue Agreement (1968), the Liability Convention (1972), the Registration Convention (1975) and the Moon Agreement (1979), which very few states have ratified.
• The boundary of space is usually taken as the Karman line at 100 km; the United States counts 80 km for awarding astronaut wings, which is why suborbital operators differ on who is an "astronaut".
• Suborbital flights (Blue Origin's New Shepard, Virgin Galactic's SpaceShipTwo) cross that line, give 3 to 5 minutes of weightlessness and come straight down; they never reach orbital velocity.
• Orbital flight needs about 7.8 km/s and far more life support and radiation shielding; SpaceX's Crew Dragon flew the all-civilian Inspiration4 mission in 2021.
• Gopichand Thotakura became the first Indian space tourist on Blue Origin's NS-25 suborbital flight in 2024.
• ISRO's planned Bharatiya Antariksh Station, whose first module model was unveiled in 2025, lists space tourism among its long-term uses.
Do not mix these up
• Suborbital vs orbital — a suborbital flight only goes up and down past the Karman line; an orbital flight must reach about 7.8 km/s to keep falling around the Earth.
• Outer Space Treaty (1967) vs Liability Convention (1972) — the Treaty sets principles; the Convention fixes the compensation a launching state owes for damage.
Also asked from this topic: Blue Origin's first orbital rocket (New Glenn, January 2025); the objective of India's Bharatiya Antariksh Station (research and future space tourism, 2025); India's first private launch vehicle (Vikram-S, 2022).
SSC Stenographer 2026 – 10 September 2026 Shift 2 · International space missions and agencies

Q17. What are the groundbreaking scientific goals of NASA's Parker Solar Probe, and which technological innovations enable it to survive the extreme conditions near the Sun?

  1. (a) To map solar wind origins and study the Sun's corona by flying closer than any previous mission, utilizing a carbon-composite heat shield and autonomous thermal regulation systems.
  2. (b) To deploy a fleet of mini-satellites into Venus's orbit for atmospheric studies, using solar sails and cryogenic cooling.
  3. (c) To observe solar flares from Earth's orbit and relay data via geostationary satellites, employing advanced adaptive optics for atmospheric correction.
  4. (d) To land a probe on the Sun's surface to measure magnetic fields directly, using a reinforced titanium hull and liquid helium cooling.
Answer & solution

Answer: (a) To map solar wind origins and study the Sun's corona by flying closer than any previous mission, utilizing a carbon-composite heat shield and autonomous thermal regulation systems.

Answer: Option 1 — To map solar wind origins and study the Sun's corona, using a carbon-composite heat shield and autonomous thermal control
The Parker Solar Probe flies straight through the Sun's corona to find where the solar wind is born.
It survives by keeping a carbon-composite heat shield pointed at the Sun automatically, so the instruments sit in its shadow.
Revision note — Parker Solar Probe and solar missions
• Launched by NASA on 12 August 2018 and named after Eugene Parker, who predicted the solar wind in 1958 — NASA's first mission named for a living scientist.
• Its Thermal Protection System is about 11.4 cm of carbon foam between carbon-composite faces; the front reaches roughly 1,370 degree C while the payload stays near 30 degree C.
• In December 2024 it passed about 6.1 million km from the Sun's surface at about 690,000 km/h — the closest and fastest any human-made object has travelled.
• It uses repeated gravity assists at Venus to tighten its orbit; the corona it studies is far hotter (over 1 million degree C) than the visible photosphere below it.
• India's Aditya-L1, launched on 2 September 2023 by PSLV-C57, observes the Sun from a halo orbit around Lagrange point L1, about 1.5 million km from Earth.
• Aditya-L1's ASPEX payload measures the solar wind, SUIT images the photosphere and chromosphere in ultraviolet, and SoLEXS studies solar X-rays.
Do not mix these up
• Parker Solar Probe vs Aditya-L1 — Parker flies into the corona; Aditya-L1 watches the Sun from a distance, parked at L1.
• Corona vs photosphere — the photosphere is the visible surface where sunspots form; the corona is the faint outer atmosphere seen during a total eclipse.
Also asked from this topic: the agency behind the Parker Solar Probe (NASA); the part of the Sun that Aditya-L1 studies (corona); its payload that monitors the solar wind (ASPEX).
SSC Stenographer 2026 – 10 September 2026 Shift 2 · Space situational awareness and debris

Q18. Which of the following statements about space debris is incorrect?

  1. (a) Space debris consists primarily of defunct satellites, spent rocket stages, and fragments from collisions.
  2. (b) The Kessler Syndrome refers to a scenario where the density of space debris is high enough to cause a cascade of collisions, exponentially increasing debris.
  3. (c) Space debris poses a threat only to satellites in geostationary orbit (GEO) and is negligible in low Earth orbit (LEO).
  4. (d) International guidelines, such as those by the Inter-Agency Space Debris Coordination Committee (IADC), recommend post-mission disposal of satellites to mitigate debris creation.
Answer & solution

Answer: (c) Space debris poses a threat only to satellites in geostationary orbit (GEO) and is negligible in low Earth orbit (LEO).

Answer: Option 3 — Space debris poses a threat only to satellites in geostationary orbit (GEO) and is negligible in low Earth orbit (LEO)
This is the statement that is incorrect, and therefore the answer.
Low Earth orbit is the most crowded and most dangerous debris region: most satellites, spent stages and collision fragments sit there, and objects meet at relative speeds of about 10 km/s.
Revision note — Space debris and its management
• Debris is made of defunct satellites, spent rocket stages, mission junk and collision fragments; over 36,000 objects larger than 10 cm are catalogued (ESA, 2024).
• Low Earth Orbit (LEO) runs up to about 2,000 km altitude; Geostationary Orbit (GEO) is at 35,786 km. LEO holds the bulk of the debris and of the collision risk.
• The Kessler Syndrome, proposed by NASA scientist Donald J. Kessler in 1978, is the runaway cascade in which each collision creates fragments that cause further collisions.
• The two biggest debris events were China's anti-satellite test on Fengyun-1C in 2007 and the 2009 Iridium-33 and Kosmos-2251 collision.
• The IADC, formed in 1993, frames the mitigation guidelines, including the 25-year rule for removing a satellite from LEO after its mission ends.
• India tracks debris through Project NETRA and the IS4OM centre at Bengaluru, and targets Debris Free Space Missions by 2030.
• India's ASAT test, Mission Shakti (27 March 2019), was fired at a low 283 km so that the fragments decayed quickly.
Do not mix these up
• LEO vs GEO for debris — the danger is concentrated in LEO; GEO is a single crowded ring but with far lower relative speeds.
• Kessler Syndrome vs a single collision — the Kessler Syndrome is the self-sustaining chain reaction, not one impact.
Also asked from this topic: the purpose of ISRO's Space Situational Awareness programme (monitoring debris); the capability of Project NETRA (debris tracking); the altitude of GEO (35,786 km).
SSC Stenographer 2026 – 9 September 2026 Shift 1 · Launch vehicles and satellites

Q19. Which of the following statements about the PSLV Orbital Experimental Module (POEM) is correct?

  1. (a) POEM is a separate satellite launched alongside PSLV missions that remains in orbit to perform manned space experiments.
  2. (b) POEM utilizes the spent PS4 stage of the PSLV as an orbital platform to host payloads, thereby enhancing mission utility without launching a new satellite bus.
  3. (c) POEM is an independent ISRO launch vehicle program intended to replace the PSLV for deploying nanosatellites.
  4. (d) POEM refers to a dedicated PSLV variant that deploys multiple satellites into geostationary orbit using reusable boosters.
Answer & solution

Answer: (b) POEM utilizes the spent PS4 stage of the PSLV as an orbital platform to host payloads, thereby enhancing mission utility without launching a new satellite bus.

Answer: Option 2 — POEM uses the spent PS4 stage of the PSLV as an orbital platform to host payloads
Instead of being abandoned as space junk, the PSLV's fourth stage is kept alive with solar panels, batteries and attitude control and flown as a free orbital laboratory.
So a payload reaches orbit with no separate satellite bus built or launched for it.
Revision note — PSLV and the POEM platform
• POEM = PSLV Orbital Experimental Module, an ISRO platform. It is neither a satellite nor a launch vehicle, and it carries no crew.
• PSLV = Polar Satellite Launch Vehicle, ISRO's medium-lift workhorse: four stages, alternating solid – liquid – solid – liquid. PS4 is the liquid fourth stage that becomes POEM.
• POEM-1 flew on PSLV-C53 (June 2022); POEM-3 on PSLV-C58 (1 January 2024, XPoSat); POEM-4 on PSLV-C60 (30 December 2024, SpaDeX).
• POEM operates in low Earth orbit. The PSLV has no reusable boosters and no cryogenic stage.
• The PSLV-XL, the most powerful variant, has six strap-on boosters and a lift-off mass of about 320 tonnes.
• India's human spaceflight programme is Gaganyaan; its small-satellite launcher is the SSLV.
Do not mix these up
• POEM vs a hosted-payload satellite — POEM reuses the rocket's own spent stage; a hosted payload still rides on a satellite bus that had to be built.
• POEM vs SSLV — POEM is a platform already in orbit; the SSLV is a launch vehicle that puts things there.
Also asked from this topic: the full form of PSLV (Polar Satellite Launch Vehicle); the vehicle that launched SpaDeX (PSLV-C60); the lift-off mass of the PSLV-XL (320 tonnes).
SSC Stenographer 2026 – 9 September 2026 Shift 1 · Indian space missions

Q20. Which of the following best highlights the multifaceted significance of India's Gaganyaan mission, beyond simply launching humans into space?

  1. (a) Gaganyaan focuses exclusively on deploying reusable satellites to reduce mission costs and eliminate dependency on international crew modules.
  2. (b) Gaganyaan demonstrates India's autonomous capability in human spaceflight, fosters development in advanced life-support systems, and strategically positions India among select nations with orbital crewed mission capabilities.
  3. (c) Gaganyaan aims to deploy a space telescope for X-ray astronomy and deep-space observation of black holes and neutron stars.
  4. (d) Gaganyaan is a robotic interplanetary mission targeting Venus, with autonomous AI payloads for analyzing the planet's sulfuric atmosphere.
Answer & solution

Answer: (b) Gaganyaan demonstrates India's autonomous capability in human spaceflight, fosters development in advanced life-support systems, and strategically positions India among select nations with orbital crewed mission capabilities.

Answer: Option 2 — Gaganyaan shows autonomous human spaceflight capability, develops life-support technology and places India among the few nations with crewed orbital capability
The significance is threefold — an indigenous crewed launch, the spin-off technologies (life support, crew escape, safe re-entry),
and strategic standing among the few nations that can fly their own astronauts.
Revision note — Gaganyaan
• Announced by PM Narendra Modi on 15 August 2018; executed by ISRO.
• Profile: 3 crew members, low Earth orbit at about 400 km, duration about 3 days, splashdown in Indian waters.
• Launcher: HLVM3, the human-rated LVM3 (GSLV Mk-III). The two critical systems are the Crew Escape System (CES) and the ECLSS, the Environmental Control and Life Support System.
• The abort test TV-D1 flew on 21 October 2023 from Sriharikota. The uncrewed precursor Gaganyaan-G1 carries the half-humanoid robot Vyommitra.
• Four astronaut-designates were named in February 2024 — Prashanth Balakrishnan Nair, Ajit Krishnan, Angad Pratap and Shubhanshu Shukla, who flew to the ISS on Axiom-4 in June 2025.
• On success India becomes the fourth nation to launch humans on its own vehicle, after the USSR/Russia, the USA and China.
Do not mix these up
• LVM3 vs HLVM3 — the same rocket, but HLVM3 is human-rated, with higher safety margins and a crew escape tower.
• Gaganyaan vs XPoSat vs Shukrayaan-1 — Gaganyaan is crewed; XPoSat is the X-ray polarimetry satellite of January 2024; Shukrayaan-1 is the planned robotic Venus orbiter.
Also asked from this topic: the crew size of Gaganyaan (3); its orbital altitude (about 400 km); the full form of HLVM3 (Human-rated LVM3); the humanoid robot on the uncrewed flight (Vyommitra).
SSC Stenographer 2026 – 9 September 2026 Shift 1 · Launch vehicles and satellites

Q21. Which of the following best explains the evolving strategic and technological significance of Earth Observation Satellites (EOS) in India's space program, and how they differ from traditional remote sensing systems?

  1. (a) EOS are space-based telescopes used exclusively for astronomical imaging and star tracking, differing from remote sensing satellites which focus only on Earth's land cover and mineral deposits.
  2. (b) EOS satellites are designed to detect gravitational waves from Earth's core, while remote sensing satellites map tectonic activities through radar interferometry.
  3. (c) EOS in India form an integrated constellation for real-time, high-resolution monitoring of weather, agriculture, disasters, and strategic assets using synthetic aperture radar and multi-spectral imaging, offering higher revisit capability and data fusion compared to traditional remote sensing satellites.
  4. (d) EOS are low-cost balloon-based systems that collect atmospheric data in real-time, replacing the need for satellite-based observation platforms.
Answer & solution

Answer: (c) EOS in India form an integrated constellation for real-time, high-resolution monitoring of weather, agriculture, disasters, and strategic assets using synthetic aperture radar and multi-spectral imaging, offering higher revisit capability and data fusion compared to traditional remote sensing satellites.

Answer: Option 3 — EOS form an integrated constellation using SAR and multi-spectral imaging, with higher revisit and data fusion than traditional remote sensing satellites
The upgrade is the constellation, not any single satellite.
Optical, multi-spectral and Synthetic Aperture Radar craft fly together, so weather, crops, floods and border areas are imaged often and the data are fused.
Revision note — India's Earth Observation Satellites
• EOS = Earth Observation Satellite. From 2020 ISRO merged its older families — IRS, Cartosat, Oceansat, RISAT — into one EOS-nn series.
• SAR images day and night and through cloud, which an optical sensor cannot. That is the key gain for disaster and border monitoring.
• EOS-01 (November 2020, PSLV-C49) was a radar-imaging satellite; EOS-04 (February 2022, PSLV-C52) carries a C-band SAR; EOS-06 is Oceansat-3; EOS-08 flew on SSLV-D3 in August 2024.
• NISAR, the NASA–ISRO dual-frequency L- and S-band SAR satellite, launched on GSLV-F16 on 30 July 2025.
• NISAR flies in a near-polar sun-synchronous orbit at about 747 km and maps land and ice every 12 days.
• Earth observation satellites use sun-synchronous polar orbits so that every pass over a place happens at the same local solar time — essential for comparing images taken months apart.
• Cartosat-3 is the high-resolution optical satellite used for agriculture, forestry, urban planning and coastal work. NRSC, Hyderabad distributes the data.
Do not mix these up
• Sun-synchronous vs geostationary — EOS fly in a low sun-synchronous polar orbit a few hundred km up; communication satellites sit at about 36,000 km over the equator.
• Earth observation vs astronomy satellites — EOS look at the Earth; AstroSat and XPoSat look outward.
• SAR vs optical imaging — radar penetrates cloud and darkness; an optical camera needs daylight and a clear sky.
Also asked from this topic: what Earth observation satellites are for (monitoring weather, land use and environmental change); NISAR's imaging type (radar imaging); its revisit period (12 days).
SSC Stenographer 2026 – 9 September 2026 Shift 1 · Launch vehicles and satellites

Q22. What are the unique design features and strategic advantages of India's Small Satellite Launch Vehicle (SSLV) compared to traditional launch vehicles like PSLV, and what challenges must be addressed to fully operationalize its commercial potential?

  1. (a) SSLV uses cryogenic propulsion to place large payloads into geostationary orbit and is fully reusable, unlike PSLV which requires booster recovery.
  2. (b) SSLV is designed for launching small payloads on-demand into low Earth orbit, offers rapid turnaround, modular manufacturing, and on-site assembly, but faces challenges in payload capacity, precision injection, and commercial competition.
  3. (c) SSLV carries hybrid electric propulsion for Earth–Moon transfer orbits and faces difficulties in re-entry shielding and autonomous docking.
  4. (d) SSLV is primarily an air-launched system capable of deploying mini-satellites globally without fixed launch infrastructure, similar to Gaganyaan's human space module.
Answer & solution

Answer: (b) SSLV is designed for launching small payloads on-demand into low Earth orbit, offers rapid turnaround, modular manufacturing, and on-site assembly, but faces challenges in payload capacity, precision injection, and commercial competition.

Answer: Option 2 — SSLV launches small payloads on demand into low Earth orbit with rapid turnaround, but faces limits of payload, injection precision and commercial competition
The SSLV is ISRO's launch-on-demand small-lift rocket — assembled in days by a small team, at low cost.
Its open problems are low payload capacity, injection accuracy and a crowded global small-launcher market.
Revision note — Small Satellite Launch Vehicle (SSLV)
• About 34 m tall, 2 m in diameter, lift-off mass about 120 tonnes.
• Configuration: three solid stages plus a liquid Velocity Trimming Module (VTM), which does the fine injection at the end.
• Capacity: about 500 kg to a 500 km low Earth orbit, or about 300 kg to a sun-synchronous polar orbit.
• Flights: SSLV-D1 (August 2022) failed to reach a stable orbit; SSLV-D2 (February 2023) placed EOS-07, Janus-1 and AzaadiSAT-2 in a 450 km circular orbit; SSLV-D3 (August 2024) carried EOS-08.
• Hindustan Aeronautics Limited won the transfer-of-technology deal for the SSLV in 2025 with a bid of ₹511 crore, moving production to industry.
• Launches are from Sriharikota. A new small-launcher spaceport is coming up at Kulasekarapattinam, Tamil Nadu, and a third launch pad at Sriharikota was approved in January 2025.
Do not mix these up
• SSLV vs PSLV — the SSLV carries about 500 kg to LEO and turns around in days; the PSLV carries about 1,750 kg to SSO and takes months to prepare.
• Solid vs cryogenic — the SSLV is all-solid plus a liquid trim module; cryogenic upper stages belong to the GSLV and LVM3, and no Indian launcher yet has reusable boosters.
Also asked from this topic: what makes the SSLV distinct from PSLV and GSLV (on-demand, low-cost launches); its lift-off mass (120 tonnes); the firm that won its technology transfer (HAL).
SSC Stenographer 2026 – 9 September 2026 Shift 2 · Launch vehicles and satellites

Q23. Which private firm launched India's first private rocket, Vikram-S?

  1. (a) Agnikul Cosmos
  2. (b) Skyroot Aerospace
  3. (c) Bellatrix Aerospace
  4. (d) Astrome Labs
Answer & solution

Answer: (b) Skyroot Aerospace

Answer: Option 2 — Skyroot Aerospace
Vikram-S, India's first privately built rocket, was developed by Skyroot Aerospace of Hyderabad.
It flew a suborbital mission named Prarambh from Sriharikota on 18 November 2022.
Revision note — India's private space sector
• Skyroot Aerospace, founded at Hyderabad in 2018, built Vikram-S; the Prarambh mission of 18 November 2022 reached a height of about 89.5 km.
• The Vikram series is named after Dr Vikram Sarabhai, the father of the Indian space programme, who founded ISRO in 1969.
• Agnikul Cosmos, an IIT Madras start-up at Chennai, flew Agnibaan SOrTeD in May 2024.
• Its engine was the world's first single-piece 3D-printed rocket engine, flown from India's first private launchpad at Sriharikota.
• IN-SPACe, set up in 2020 with headquarters at Ahmedabad, is the single-window body that authorises and regulates private space activity.
• NewSpace India Limited (NSIL), formed in 2019, is ISRO's commercial arm; the earlier one was Antrix Corporation (1992).
• Other Indian space start-ups: Bellatrix Aerospace (in-space propulsion), Pixxel (hyperspectral imaging satellites), Dhruva Space and Astrome Technologies (communications).
Do not mix these up
• Skyroot vs Agnikul — Skyroot flew the first Indian private rocket, Vikram-S (2022); Agnikul flew Agnibaan (2024) with a 3D-printed engine.
• IN-SPACe vs NSIL — IN-SPACe authorises and regulates private players; NSIL sells ISRO's launches and products commercially.
Also asked from this topic: the developer of Vikram-S, India's first private launch vehicle (Skyroot Aerospace, SSC MTS 2026); the first private Indian company to launch a rocket into space (Skyroot Aerospace, SSC Selection Post 2025).
RRB Group D 2025-26 – 14 August 2026 Shift 2 · ISRO - history and centres

Q24. Which organization launched the Young Scientists Programme, YUVIKA-2026, to nurture scientific curiosity among young students in India?

  1. (a) Ministry of Education
  2. (b) Council of Scientific and Industrial Research
  3. (c) National Council of Educational Research and Training
  4. (d) Indian Space Research Organisation
Answer & solution

Answer: (d) Indian Space Research Organisation

Answer: Option 4 – Indian Space Research Organisation.
•ISROruns the Young Scientists Programme, YUVIKA-2026.
RRB Group D 2025-26 – 12 August 2026 Shift 1 · Missiles and weapon systems

Q25. In 2025, which DRDO-led project was identified as the India’s strategic initiative for developing an indigenous extended-range surface-to-air missile system capable of multi-layer threat interception?

  1. (a) Project SURAKSHA
  2. (b) Project Kusha
  3. (c) Raksha Shakti project
  4. (d) DEFENCE-X
Answer & solution

Answer: (b) Project Kusha

Answer: Option 2 – Project Kusha.
•Project Kushais DRDO's indigenous long-range (extended-range) surface-to-air missile programme.
RRB Group D 2025-26 – 10 August 2026 Shift 3 · Indian armed forces - structure and ranks

Q26. Which state hosted the Maroon Beret Ceremonial Parade in 2026 marking the successful completion of training of the Indian Air Force Special Forces operatives at Air Force Station, Chandinagar?

  1. (a) Punjab
  2. (b) Haryana
  3. (c) Rajasthan
  4. (d) Uttar Pradesh
Answer & solution

Answer: (d) Uttar Pradesh

Answer: Option 4 – Uttar Pradesh.
• The Maroon Beret Ceremonial Parade (IAF Special Forces, Air Force Station Chandinagar) was held inUttar Pradeshin 2026.
RRB Group D 2025-26 – 4 August 2026 Shift 3 · Indian space missions

Q27. Which instrument is related to Chandrayaan-3 and delivered critical 'ground truth' data on the Moon’s plasma environment in December 2025?

  1. (a) IIRS-L
  2. (b) RAMBHA-LP
  3. (c) CHACE-2
  4. (d) M3
Answer & solution

Answer: (b) RAMBHA-LP

Answer: Option 2 — RAMBHA-LP
TheRAMBHA-LPpayload (Chandrayaan-3) gave ground-truth data on the Moon's plasma environment → Option 2. *(Verify against the official key.)*
RRB NTPC UG CBT-1 2025-26 – 13 June 2026 Shift 3 · Launch vehicles and satellites

Q28. Which platform successfully completed in‑orbit testing of an environmentally friendly green propulsion system?

  1. (a) PSLV payload module from TDF
  2. (b) Geosynchronous satellite
  3. (c) GSLV upper stage
  4. (d) Chandrayaan lander
Answer & solution

Answer: (a) PSLV payload module from TDF

Topic: ISRO's Green Propulsion System
PSLV Orbital Experimental Module (POEM)
ISRO's Technology Demonstration Forum (TDF) used PSLV's fourth stage as an orbital platform.
Green Propulsion System
Successfully tested hydroxyl ammonium nitrate (HAN)-based green propellant.
This is environmentally friendly alternative to hydrazine.
POEM-3 mission (2024) demonstrated this technology in orbit.
Answer: Option 1 → PSLV payload module from TDF
SSC GD 2026 – 30 May 2026 Shift 2 · Launch vehicles and satellites

Q29. What is the lift-off mass of ISRO's Small Satellite Launch Vehicle (SSLV)?

  1. (a) 420 tonnes
  2. (b) 120 tonnes
  3. (c) 840 tonnes
  4. (d) 1020 tonnes
Answer & solution

Answer: (b) 120 tonnes

Correct Answer: 120 tonnes (Option 2)
ISRO's Small Satellite Launch Vehicle (SSLV) has a lift-off mass of approximately 120 tonnes. It is a three-stage, all-solid launch vehicle designed to provide low-cost, on-demand launch services for small satellites (up to 500 kg to Low Earth Orbit). The SSLV is much smaller and lighter than ISRO's other rockets such as PSLV (~320 tonnes) and GSLV Mk III (~640 tonnes).
Why others are wrong:
- 420 tonnes: This is approximately the mass of PSLV-XL variant; not SSLV.
- 840 tonnes: Does not correspond to any standard ISRO vehicle mass.
- 1020 tonnes: This is not the mass of SSLV; it exceeds even the GSLV Mk III.
SSC GD 2026 – 30 May 2026 Shift 3 · Launch vehicles and satellites

Q30. The first successful Indian Polar Satellite Launch Vehicle PSLV-D2 was a ____-stage rocket.

  1. (a) 2
  2. (b) 3
  3. (c) 4
  4. (d) 6
Answer & solution

Answer: (c) 4

Correct Answer: 4 stages (Option 3)
The PSLV (Polar Satellite Launch Vehicle) is a 4-stage launch vehicle developed by ISRO. It alternates between solid (1st and 3rd stages) and liquid (2nd and 4th stages) propulsion systems. PSLV-D1 (1993) was the first developmental flight and failed. PSLV-D2 (October 15, 1994) was the first successful flight of PSLV, placing the IRS-P2 satellite in orbit. PSLV has since become ISRO's most reliable workhorse rocket.
Why others are wrong:
- 2 stages: PSLV is not a two-stage rocket.
- 3 stages: PSLV has four stages, not three.
- 6 stages: No Indian launch vehicle currently in service has six stages.
SSC GD 2026 – 30 May 2026 Shift 1 · Launch vehicles and satellites

Q31. In the context of India's launch vehicles, GSLV Mk-III can carry up to _____ kg to Geostationary Transfer Orbits (GTO).

  1. (a) 4000
  2. (b) 8500
  3. (c) 9000
  4. (d) 10000
Answer & solution

Answer: (a) 4000

Correct Answer: 4000 kg — Option (a)
GSLV Mk-III (LVM3) can carry up to 4000 kg to Geostationary Transfer Orbit (GTO). About GSLV Mk-III (LVM3): Full name: Geosynchronous Satellite Launch Vehicle Mark III; Also renamed: LVM3 (Launch Vehicle Mark 3) — renamed in 2022; Developer: ISRO (Indian Space Research Organisation ); Type: 3-stage launch vehicle; Payload capacity: GTO (Geostationary Transfer Orbit): 4,000 kg; LEO (Low Earth Orbit): 8,000-10,000 kg; GSLV Mk-III stages: Stage 1 (S200): Two solid fuel strap-on boosters; Stage 2 (L110): Liquid fuel core stage; Stage 3 (C25): Cryogenic upper stage (using LOX/LH₂); Significance of C25 Cryogenic Engine: India developed its own cryogenic engine — C25 (Cryogenic Engine 25); Earlier, India had to import cryogenic engines; Russia initially agreed to transfer technology but was blocked by US pressure (MTCR concerns); India independently developed cryogenic technology; Key missions of GSLV Mk-III/LVM3: Chandrayaan-2 (2019): Lunar orbiter and lander; Chandrayaan-3 (2023): Successfully landed on Moon's south pole; OneWeb missions (2022-23): Commercial satellite launches; Comparison of ISRO launch vehicles: SLV-3: 40 kg to LEO; ASLV: 150 kg to LEO; PSLV: ~3,800 kg to LEO; GSLV Mk-II: ~2,500 kg to GTO; GSLV Mk-III (LVM3): 4,000 kg to GTO, ~8,000 kg to LEO; Why GTO matters: Satellites for communication are placed in Geostationary Orbit (36,000 km altitude); GTO is an elliptical transfer orbit used to reach GEO; GSLV Mk-III can launch 4-tonne class communication satellites — India's GSAT series, etc.
Option (b) 8500 — Incorrect: GSLV Mk-III does NOT carry 8,500 kg to Geostationary Transfer Orbit (GTO); the payload capacity to GTO is 4,000 kg; 8,500 kg is close to its LEO capacity (approximately 8,000-10,000 kg to LEO); GTO and LEO capacities are different — GTO is much harder to reach (requires more delta-v), hence lower payload. The candidate incorrectly selected this option.
Option (c) 9000 — Incorrect: GSLV Mk-III does NOT carry 9,000 kg to GTO; the payload capacity to GTO is 4,000 kg; 9,000 kg might approximate its LEO capacity; the question specifically asks about GTO (Geostationary Transfer Orbit) capacity, which is 4,000 kg for GSLV Mk-III.
Option (d) 10000 — Incorrect: GSLV Mk-III does NOT carry 10,000 kg to GTO; the payload capacity to GTO is 4,000 kg; 10,000 kg is approximately its maximum LEO capacity; GTO requires much more energy than LEO (GTO is at ~36,000 km perigee equivalent, while LEO is ~400-2,000 km), so GTO payload is significantly less than LEO payload.
SSC GD 2026 – 29 May 2026 Shift 1 · ISRO - history and centres

Q32. The Thumba Equatorial Rocket Launching Station is in _____.

  1. (a) Karnataka
  2. (b) Gujarat
  3. (c) Kerala
  4. (d) Maharashtra
Answer & solution

Answer: (c) Kerala

Correct Answer: Kerala — Option (c)
The Thumba Equatorial Rocket Launching Station (TERLS) is located in Kerala. About Thumba Equatorial Rocket Launching Station (TERLS): Location: Thumba village, near Thiruvananthapuram (Trivandrum), Kerala; Significance: India's FIRST rocket launching station; First rocket launch: November 21, 1963 — India's first sounding rocket (Nike Apache) was launched from Thumba ; This date is celebrated as National Space Day (now also called Antariksh Diwas); Why Thumba was chosen: Thumba lies near the magnetic equator of the Earth (Dip Equator passes through Thumba ); The geomagnetic equator is ideal for studying ionosphere and equatorial phenomena; Rockets launched near the magnetic equator can enter equatorial orbits efficiently; The facility was initially established as a collaborative project with NASA, Soviet Union, France, and other countries; INCOSPAR: Indian National Committee for Space Research — the predecessor to ISRO; established in 1962 by Jawaharlal Nehru and Vikram Sarabhai; It was under INCOSPAR that TERLS was established; About Dr. Vikram Sarabhai: Father of India's Space Programme ; He chose Thumba for the rocket launching station; ISRO headquarters is in Bengaluru (Karnataka) but TERLS is in Kerala; Current status: TERLS is now part of VSSC (Vikram Sarabhai Space Centre), the major technical centre of ISRO in Thiruvananthapuram; VSSC develops rockets and space vehicles for ISRO.
Option (a) Karnataka — Incorrect: The Thumba Equatorial Rocket Launching Station is NOT in Karnataka; it is in Thiruvananthapuram (Trivandrum), Kerala; ISRO's main headquarters is in Bengaluru, Karnataka, but TERLS (India's first rocket launching station) is specifically located in Thumba , Kerala. The candidate selected this incorrect option.
Option (b) Gujarat — Incorrect: The Thumba Equatorial Rocket Launching Station is NOT in Gujarat; it is in Kerala; Gujarat is home to the ISRO Launch Vehicle Unit and other space facilities, but TERLS — India's first rocket launching station — is at Thumba , near Thiruvananthapuram, Kerala.
Option (d) Maharashtra — Incorrect: The Thumba Equatorial Rocket Launching Station is NOT in Maharashtra; it is at Thumba , Thiruvananthapuram, Kerala; Maharashtra has VSSC development units and the National Remote Sensing Centre, but India's first rocket launching station (TERLS) is in Kerala.
SSC GD 2026 – 29 May 2026 Shift 1 · Nuclear programme and institutions

Q33. Which BARC developed reactor achieved first criticality with LEU fuel?

  1. (a) PURNE
  2. (b) APSARA-U
  3. (c) DHRUVA
  4. (d) KAMINI
Answer & solution

Answer: (b) APSARA-U

Correct Answer: APSARA-U — Option (b)
APSARA-U is the BARC-developed reactor that achieved first criticality with LEU (Low Enriched Uranium) fuel. About APSARA-U: Full name: APSARA-Upgraded; Type: Swimming pool type research reactor; Developer: BARC (Bhabha Atomic Research Centre), Mumbai; Achievement: Achieved first criticality on September 10, 2018; Fuel: LEU (Low Enriched Uranium) — uses 20% enriched uranium; Power: 2 MW (upgraded from original APSARA's 1 MW); About the original APSARA: India's FIRST nuclear reactor; Achieved criticality on August 4, 1956 (the day India became 'nuclear capable'); Built with British assistance; Named 'Apsara' by PM Jawaharlal Nehru; Was shut down in 2009 after 53 years of operation; APSARA-U replaced the original APSARA with Indian-made LEU fuel instead of the imported Highly Enriched Uranium (HEU); About LEU vs HEU: HEU (Highly Enriched Uranium): >20% U-235; used in nuclear weapons; original APSARA used HEU; LEU (Low Enriched Uranium): <20% U-235; safer, proliferation-resistant; APSARA-U uses LEU — a significant achievement showing India's self-sufficiency in nuclear fuel; About other BARC reactors: PURNE: Pakistan's reactor? Not BARC's; DHRUVA: India's largest research reactor (100 MW thermal); achieved criticality in 1985; uses natural uranium fuel; KAMINI: World's first reactor using Uranium-233 fuel; located at Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam , Tamil Nadu; 30 kW power; The APSARA-U is specifically the one that achieved first criticality with LEU (indigenously developed).
Option (a) PURNE — Incorrect: PURNE is NOT a BARC reactor that achieved first criticality with LEU fuel; this is not a standard name of a well-known Indian research reactor; the reactor that achieved first criticality with LEU is APSARA-U (at BARC, Mumbai).
Option (c) DHRUVA — Incorrect: DHRUVA is a BARC research reactor but it did NOT achieve first criticality with LEU fuel — it uses Natural Uranium (unenriched) as fuel; DHRUVA achieved criticality in 1985 and operates at 100 MW thermal power; it is used for plutonium production and neutron research; APSARA-U achieved first criticality with LEU fuel.
Option (d) KAMINI — Incorrect: KAMINI is a unique research reactor (located at IGCAR Kalpakkam , NOT BARC Mumbai) that runs on Uranium-233 (from thorium breeding cycle) — NOT LEU; KAMINI ( Kalpakkam Mini reactor) achieved criticality in 1996 and operates at 30 kW; it is the world's first reactor using U-233 fuel; APSARA-U (at BARC) achieved first criticality with LEU fuel.
SSC GD 2026 – 29 May 2026 Shift 2 · Launch vehicles and satellites

Q34. The first successful Indian Polar Satellite Launch Vehicle was _____.

  1. (a) PSLV-D2
  2. (b) PSLV-C5
  3. (c) PSLV-C7
  4. (d) PSLV-C15
Answer & solution

Answer: (a) PSLV-D2

Correct Answer: PSLV-D2 — Option (a)
The first SUCCESSFUL Indian Polar Satellite Launch Vehicle was PSLV-D2. About PSLV Launch History: PSLV (Polar Satellite Launch Vehicle) is India's workhorse rocket developed by ISRO (Indian Space Research Organisation ); PSLV Development Missions (D-series): PSLV-D1 (September 20, 1993): First developmental flight of PSLV; Launch: Sriharikota (SHAR); Payload: IRS-1E (Indian Remote Sensing satellite); Outcome: FAILURE — a software error in the control system caused the rocket to deviate from its trajectory and fall into the sea after 317 seconds; PSLV-D2 (October 15, 1994): Second developmental flight; Launch: Sriharikota ; Payload: IRS-P2 (Indian Remote Sensing satellite); Outcome: COMPLETE SUCCESS — First successful PSLV flight; Placed IRS-P2 in a sun-synchronous polar orbit; PSLV-D3 (March 21, 1996): Third developmental flight — Successful; Payload: IRS-P3; PSLV-C1 (September 29, 1997): First operational flight of PSLV — Successful; Payload: IRS-1D; About PSLV series naming: D1, D2, D3: Developmental versions (1993-1996); C1 onwards: Commercial/Operational versions (C1, C2, C3... C58, etc.); PSLV variants: PSLV-G (Generic), PSLV-CA (Core Alone), PSLV-XL (Extra Large), PSLV-QL (Quad Liquid), PSLV-DL (Dual Liquid); About PSLV achievements: Chandrayaan-1 (2008), Mangalyaan/Mars Orbiter Mission (2013), IRNSS/ NavIC satellites, AstroSat (2015), 104 satellites in one launch (2017 — world record at the time).
Option (b) PSLV-C5 — Incorrect: PSLV-C5 was NOT the first successful PSLV; PSLV-C5 (launched in 2002) was the 5th operational (commercial) flight of PSLV, carrying KALPANA-1 (METSAT) satellite; the first successful PSLV was PSLV-D2 (launched on October 15, 1994), which was the second developmental flight of PSLV.
Option (c) PSLV-C7 — Incorrect: PSLV-C7 was NOT the first successful PSLV; it was the 7th operational flight of PSLV (launched in 2007); it simultaneously launched 4 satellites (Cartosat-2, SRE-1, LAPAN-TUBSAT, Pehuensat-1); the first successful PSLV was PSLV-D2 (October 15, 1994). The candidate incorrectly selected this option.
Option (d) PSLV-C15 — Incorrect: PSLV-C15 was NOT the first successful PSLV; it was the 15th operational flight of PSLV (launched in 2010); it carried Cartosat-2B and 4 other satellites; the first successful PSLV was PSLV-D2 (October 15, 1994), the second developmental flight of PSLV.
SSC GD 2026 – 29 May 2026 Shift 3 · Launch vehicles and satellites

Q35. In the context of Indian satellite launch vehicle, how many stages did the ASLV have?

  1. (a) 2
  2. (b) 3
  3. (c) 4
  4. (d) 5
Answer & solution

Answer: (d) 5

Correct Answer: 5 stages — Option (d)
The ASLV (Augmented Satellite Launch Vehicle) had 5 stages. About ASLV: Full name: Augmented Satellite Launch Vehicle; Developer: ISRO (Indian Space Research Organisation ); Type: 5-stage solid propellant rocket; ASLV stages: Stage 0: Two strap-on solid rocket motors (used as boosters at ignition); Stage 1: Core solid motor; Stage 2: Solid motor; Stage 3: Solid motor; Stage 4: Solid motor; Total: 5 stages (counting strap- ons as Stage 0, plus 4 core stages); Purpose: To develop technologies for future launch vehicles; Bridge between SLV-3 (capable of 40 kg LEO payload) and PSLV; Could carry 150 kg to Low Earth Orbit (LEO); History and performance: ASLV-D1 (March 1987): FAILURE — vehicle veered off course; ASLV-D2 (July 1988): FAILURE — fairing did not separate; ASLV-D3 (May 1992): SUCCESS — placed SROSS-C in orbit (150 kg); ASLV-D4 (May 1994): SUCCESS — placed SROSS-C2 in orbit; Out of 4 launches: 2 successes, 2 failures; Note: ASLV was retired after 4 launches; PSLV (which followed) has been far more successful; Comparison of ISRO launch vehicles: SLV-3 (4 stages, solid): 40 kg to LEO; ASLV (5 stages, all solid): 150 kg to LEO; PSLV (4 stages, alternating solid and liquid): 3,800 kg to LEO; GSLV Mk III / LVM3 (3 stages): 10,000 kg to LEO; Technologies developed during ASLV: Strap-on technology, Closed-loop guidance, Bulbous heat shield, High speed computers.
Option (a) 2 — Incorrect: The ASLV did NOT have only 2 stages; it had 5 stages (including two strap-on boosters as Stage 0 plus 4 core stages); 2 stages would describe a very simple rocket configuration — not the ASLV which was designed to test multiple staging technologies for future vehicles. The candidate incorrectly selected this option.
Option (b) 3 — Incorrect: The ASLV did NOT have 3 stages; it had 5 stages; 3 stages describes some other vehicles (like the GSLV Mk III/LVM3 has 3 stages — two solid strap- ons + liquid core + cryogenic upper stage); ASLV was a 5-stage all solid propellant vehicle.
Option (c) 4 — Incorrect: The ASLV did NOT have 4 stages; it had 5 stages; 4 stages describes the PSLV (Polar Satellite Launch Vehicle) which has 4 alternating solid and liquid stages (PS1-PS4); ASLV had 5 stages — Stage 0 (two strap-on solid motors) + Stages 1, 2, 3, 4 (core solid stages).
SSC GD 2026 – 27 May 2026 Shift 1 · ISRO - history and centres

Q36. In which year was the Space Commission
(Antariksha Aayog) established in India?

  1. (a) 1961
  2. (b) 1972
  3. (c) 1984
  4. (d) 1998
Answer & solution

Answer: (b) 1972

Correct Answer: 1972 — Option (b)
The Space Commission (Antariksha Aayog) was established in India in 1972. About the Space Commission of India: Established: 1972 (by a Government of India Resolution on June 1, 1972); Along with: The Department of Space (DOS) was also created in 1972; Prime Minister: Indira Gandhi (PM at the time — she also held the Space portfolio); First Chairman of Space Commission: Dr. Vikram Sarabhai (founding father of India's space program, though he died in December 1971); Second Chairman: Dr. Satish Dhawan; Role of the Space Commission: Highest policy-making body for India's space program; Sets the direction and policies for India's space activities; The Space Commission is chaired by the Chairman of ISRO; The Department of Space (DOS) implements the decisions of the Space Commission; About ISRO's establishment timeline: 1962: Indian National Committee for Space Research (INCOSPAR) established under Dr. Vikram Sarabhai (precursor to ISRO); 1963: First rocket launched from Thumba Equatorial Rocket Launching Station (TERLS), Kerala; 1969: ISRO (Indian Space Research Organisation ) established — replacing INCOSPAR; 1972: Space Commission and Department of Space created — giving formal government structure to the space program; 1975: India's first satellite Aryabhata launched (by Soviet Union); 1980: India's first indigenous satellite launch — Rohini satellite using SLV-3 rocket; About 1961: 1961 is NOT a significant year for India's space program; INCOSPAR was established in 1962.
Option (a) 1961 — Incorrect: The Space Commission was NOT established in 1961; the Indian space program's precursor (INCOSPAR — Indian National Committee for Space Research) was established in 1962, and the formal Space Commission was established in 1972. The candidate selected this incorrect option.
Option (c) 1984 — Incorrect: The Space Commission was established in 1972, not 1984; 1984 is significant for India's space program as the year Rakesh Sharma became the first Indian to go to space (on the Soviet Soyuz T-11 mission), but it is NOT the year the Space Commission was established.
Option (d) 1998 — Incorrect: The Space Commission was established in 1972 — not 1998; 1998 was the year of India's Pokhran-II nuclear tests; the Space Commission had been functioning for 26 years before 1998.
SSC GD 2026 – 27 May 2026 Shift 2 · International space missions and agencies

Q37. Which NASA mission will explore Jupiter's moon Europa?

  1. (a) Europa Orbiter
  2. (b) Europa Clipper
  3. (c) Galileo-2
  4. (d) JUICE
Answer & solution

Answer: (b) Europa Clipper

Correct Answer: Europa Clipper — Option (b)
NASA's Europa Clipper mission is designed to explore Jupiter's moon Europa. About Europa Clipper: Mission: Europa Clipper; Agency: NASA (National Aeronautics and Space Administration); Launch: October 14, 2024 (launched aboard SpaceX Falcon Heavy rocket); Destination: Europa — one of Jupiter's largest moons; Arrival at Jupiter system: Expected in April 2030; Mission objectives: Investigate whether Europa's subsurface ocean could support life; Study Europa's ice shell, geology, and composition; Determine the depth and salinity of the subsurface ocean; Map potential landing sites for future missions; About Europa (Jupiter's moon): 6th largest moon in the Solar System; Has a global ocean of liquid water beneath its icy surface; The ice shell is estimated to be 10-30 km thick; The subsurface ocean may have more water than all of Earth's oceans combined; Considered one of the most promising places in the Solar System to search for extraterrestrial life; Europa gets energy from tidal heating (due to gravitational interaction with Jupiter); About other options: Europa Orbiter: Not an active NASA mission; Europa Clipper flies by Europa repeatedly (not an orbiter of Europa specifically — it orbits Jupiter and makes flybys); Galileo-2: Not a real mission; the original Galileo mission (1989-2003) explored Jupiter and its moons; JUICE: ESA's (European Space Agency) mission — Jupiter Icy Moons Explorer; launched April 2023; will study Europa, Ganymede, and Callisto; JUICE is NOT NASA's mission — it is ESA's.
Option (a) Europa Orbiter — Incorrect: 'Europa Orbiter' was a proposed concept mission that was never launched; the actual NASA mission to explore Europa is called 'Europa Clipper' (launched October 2024); Europa Clipper does not orbit Europa directly but performs multiple flybys while orbiting Jupiter.
Option (c) Galileo-2 — Incorrect: 'Galileo-2' is not a real NASA mission; the original NASA Galileo mission (1989-2003) explored Jupiter and its moons (including Europa) and was the first spacecraft to orbit Jupiter; the mission to explore Europa is Europa Clipper; there is no 'Galileo-2' mission. The candidate selected this incorrect option.
Option (d) JUICE — Incorrect: JUICE (Jupiter Icy Moons Explorer) is the European Space Agency's (ESA's) mission to explore Jupiter's icy moons (Europa, Ganymede, Callisto) — NOT NASA's mission; JUICE was launched in April 2023 and will arrive at Jupiter in 2031; the NASA mission for Europa exploration is the Europa Clipper.
SSC GD 2026 – 27 May 2026 Shift 3 · International space missions and agencies

Q38. Apollo-XI mission is associated with which of the following countries?

  1. (a) France
  2. (b) China
  3. (c) India
  4. (d) USA
Answer & solution

Answer: (d) USA

Correct Answer: USA — Option (d)
The Apollo XI (Apollo 11) mission is associated with the USA (United States of America). About Apollo 11 (Apollo XI): Mission: Apollo 11; Agency: NASA (National Aeronautics and Space Administration), USA; Date: July 16-24, 1969; Achievement: First crewed lunar landing — humans set foot on the Moon for the first time in history; Crew: Neil Armstrong (Commander) — First human to walk on the Moon; Buzz Aldrin (Lunar Module Pilot) — Second human to walk on the Moon; Michael Collins (Command Module Pilot) — Orbited the Moon while Armstrong and Aldrin landed; Landing site: Sea of Tranquility (Mare Tranquillitatis) on the Moon; Date of landing: July 20, 1969; Neil Armstrong's famous words: 'That's one small step for man, one giant leap for mankind'; Moon walk duration: About 2.5 hours on the lunar surface; Samples collected: About 21.5 kg of lunar rock and soil samples; Return: Safe splashdown in the Pacific Ocean on July 24, 1969; Context — Space Race: The USA and USSR (Soviet Union) were in a 'Space Race' during the Cold War; USSR launched the first satellite (Sputnik, 1957) and first human in space (Yuri Gagarin, 1961); USA won the Moon race with Apollo 11 in 1969; About the Apollo Program: 17 Apollo missions total (Apollo 1-17); Apollo 1: Fatal fire during training (1967); Apollo 8: First crewed mission to orbit the Moon (1968); Apollo 11: First Moon landing (1969); Apollo 17: Last Moon landing (1972).
Option (a) France — Incorrect: The Apollo XI mission has nothing to do with France; Apollo 11 was an American (USA/NASA) mission that achieved the first human Moon landing in July 1969; France's space agency is CNES (Centre National d'Études Spatiales ) and France has not conducted Moon landing missions.
Option (b) China — Incorrect: Apollo XI was NOT China's mission; it was an American (NASA) mission; China's Moon missions are called Chang'e missions (named after the Chinese Moon goddess); Chang'e 4 landed on the far side of the Moon in 2019, and Chang'e 5 returned lunar samples in 2020 — these are China's lunar missions, separate from Apollo.
Option (c) India — Incorrect: Apollo XI was NOT India's mission; it was an American (NASA) mission; India's Moon missions are called Chandrayaan ; Chandrayaan-1 (2008), Chandrayaan-2 (2019), and Chandrayaan-3 (2023) — Chandrayaan-3 achieved a soft landing near the Moon's south pole in August 2023, making India the first country to land near the lunar south pole. The candidate selected this incorrect option.
SSC GD 2026 – 26 May 2026 Shift 1 · International space missions and agencies

Q39. Which country landed the first rover on the far side of the Moon?

  1. (a) USA
  2. (b) China
  3. (c) India
  4. (d) Russia
Answer & solution

Answer: (b) China

Correct Answer: China — Option (b)
China became the first country to land a rover on the far side of the Moon. About China's Moon Far Side Landing: Mission: Chang'e-4 ( 嫦娥四号 ); Landing date: January 3, 2019; Landing site: Von Kármán crater in the South Pole-Aitken Basin (one of the largest and oldest impact craters in the solar system); Rover: Yutu-2 (Jade Rabbit-2); Yutu-2 has set the record for the longest operational period of any rover on the lunar surface; Communication challenge: The far side of the Moon never faces Earth, so direct communication is impossible; China solved this by deploying a relay satellite — Queqiao-1 (in a halo orbit around the Earth-Moon L2 Lagrange point) to relay signals between the rover and Earth; Why far side exploration is significant: The far side is geologically different from the near side — it has a thicker crust and more ancient terrain; It is protected from Earth's radio interference — ideal for radio astronomy; Scientists hope to study the universe's 'Dark Ages' (before stars formed) from the far side; About subsequent far-side missions: Chang'e-6 (2024): China retrieved the first samples from the far side of the Moon from the Apollo crater; About India's Moon missions: Chandrayaan-1 (2008): Orbiter — confirmed water on Moon; Chandrayaan-2 (2019): Orbiter (success) + Vikram lander (crash-landed); Chandrayaan-3 (2023): Successfully landed Pragyan rover near the South Pole.
Option (a) USA — Incorrect: The USA's NASA Apollo missions (1969-1972) successfully landed humans on the Moon's NEAR side — the USA has NOT landed a rover on the FAR side of the Moon; China was the first to achieve this with Chang'e-4 in January 2019. The candidate selected this incorrect option.
Option (c) India — Incorrect: India's Chandrayaan-3 mission (August 23, 2023) successfully landed the Pragyan rover near the lunar South Pole — but this was on the near side of the Moon, not the far side; China was the first country to land on the far side of the Moon.
Option (d) Russia — Incorrect: Russia (formerly Soviet Union) was the first to land spacecraft on the Moon (Luna 9, 1966) and deploy a rover (Lunokhod 1, 1970) — but all Soviet/Russian lunar missions landed on the near side; China is the only country to have landed on the far side of the Moon.
SSC GD 2026 – 26 May 2026 Shift 1 · ISRO - history and centres

Q40. Which of the following Indian agencies is responsible for managing satellite remote sensing for environmental study?

  1. (a) FSI - Forest Survey of India
  2. (b) CPCB - Central Pollution Control Board
  3. (c) ISRO - Indian Space Research Organisation
  4. (d) MoEFCC - Ministry of Environment, Forest and Climate Change
Answer & solution

Answer: (c) ISRO - Indian Space Research Organisation

Correct Answer: ISRO - Indian Space Research Organisation — Option (c)
ISRO (Indian Space Research Organisation ) is responsible for managing satellite remote sensing for environmental study in India. About ISRO and Remote Sensing: ISRO manages and operates India's earth observation satellites for remote sensing; Key remote sensing initiative: National Remote Sensing Centre (NRSC) — a unit of ISRO based in Hyderabad; NRSC provides satellite data and remote sensing services for: Environmental monitoring, Forest cover assessment, Land use/land cover mapping, Water resource mapping, Disaster management, Agricultural monitoring, Urban sprawl monitoring; ISRO's Earth Observation Satellites: RESOURCESAT series: Land resources monitoring (vegetation, crops, forests); CARTOSAT series: High-resolution cartographic applications; OCEANSAT series: Ocean color, wind vectors, sea surface temperature; RISAT series: Radar imaging for all-weather monitoring; INSAT/KALPANA: Meteorological observation; How remote sensing helps environment: Monitoring deforestation, desertification, glacier retreat, wetland changes, coastal erosion, air quality (using satellite sensors), and biodiversity changes; About other agencies: FSI (Forest Survey of India): Uses ISRO's satellite data to assess forest cover — but FSI is a USER of remote sensing data, not the manager of satellites; CPCB (Central Pollution Control Board): Monitors water and air pollution — doesn't manage satellites; MoEFCC : Policy body for environment — doesn't manage satellites.
Option (a) FSI - Forest Survey of India — Incorrect: The Forest Survey of India (FSI) is an organization under MoEFCC that assesses forest cover using satellite remote sensing DATA — but it does NOT manage the satellites; ISRO provides the satellite data that FSI uses for its biennial State of Forest Report.
Option (b) CPCB - Central Pollution Control Board — Incorrect: The CPCB monitors air and water pollution through ground-based monitoring stations (CAAQMS — Continuous Ambient Air Quality Monitoring Stations) — it does NOT manage satellite remote sensing systems; ISRO is the correct answer. The candidate selected this incorrect option.
Option (d) MoEFCC - Ministry of Environment, Forest and Climate Change — Incorrect: MoEFCC is the nodal ministry for environmental policy and regulation — it uses data from various sources including ISRO's satellites, but it does NOT manage satellite remote sensing systems; ISRO is responsible for managing satellite remote sensing.
SSC GD 2026 – 26 May 2026 Shift 3 · Launch vehicles and satellites

Q41. What is the primary purpose of ISRO's NavIC system?

  1. (a) Weather forecasting
  2. (b) Earth imaging
  3. (c) Regional navigation
  4. (d) Space communication
Answer & solution

Answer: (c) Regional navigation

Correct Answer: Regional navigation — Option (c)
NavIC (Navigation with Indian Constellation) is ISRO's regional satellite navigation system designed to provide accurate positioning and timing services. About NavIC : Full name: Navigation with Indian Constellation; Also known as: IRNSS (Indian Regional Navigation Satellite System) — the earlier name; Developed by: ISRO (Indian Space Research Organisation ); Type: Regional Satellite Navigation System — India's own version of GPS; Coverage: India and a region extending approximately 1,500 km around India (covering the Indian subcontinent and surrounding ocean areas); Purpose: To provide accurate real-time positioning (latitude, longitude, altitude) and timing services; Applications: Navigation for all types of vehicles (road, rail, air, maritime), Terrestrial, aerial, and marine navigation, Visual and voice navigation for drivers, Tracking of vehicles and fleet management, Mapping and geodetic data capture, Search and rescue operations, Precision timing for telecom networks, Support for disaster management; Constellation: NavIC consists of 7 operational satellites: 3 in Geostationary orbit (GEO) and 4 in Geosynchronous Inclined orbit (IGSO); Navigation signals: Operates on two frequency bands — L5 and S band; Provides: Standard Positioning Service (SPS) — for civilian use; Restricted Service (RS) — for strategic/authorized users; Comparison with other navigation systems: GPS (USA) — Global; GLONASS (Russia) — Global; Galileo (Europe) — Global; BeiDou (China) — Global; QZSS (Japan) — Regional; NavIC (India) — Regional; NavIC is India's own independent navigation system, reducing dependence on foreign GPS systems.
Option (a) Weather forecasting — Incorrect: Weather forecasting uses meteorological satellites (like ISRO's INSAT/METSAT series, e.g., Kalpana-1, INSAT-3D) — NOT NavIC ; NavIC satellites are specifically designed for navigation and positioning, not weather data collection.
Option (b) Earth imaging — Incorrect: Earth imaging (remote sensing) is performed by ISRO's earth observation satellites like RESOURCESAT, CARTOSAT, RISAT series — NOT NavIC ; NavIC's purpose is regional satellite navigation, not imaging.
Option (d) Space communication — Incorrect: Space communication is served by ISRO's GSAT series of communication satellites — NOT NavIC ; NavIC is specifically a navigation satellite system providing positioning and timing services, not communication. The candidate selected this incorrect option.
SSC GD 2026 – 25 May 2026 Shift 2 · Launch vehicles and satellites

Q42. The indigenous launch vehicle used in Indian satellite launches in the 1980s was _____.

  1. (a) SLV-3
  2. (b) PSLV
  3. (c) ASLV
  4. (d) GSLV
Answer & solution

Answer: (a) SLV-3

Correct Answer: SLV-3 — Option (a)
The SLV-3 (Satellite Launch Vehicle-3) was India's indigenous launch vehicle used for satellite launches in the 1980s. About SLV-3: Full name: Satellite Launch Vehicle-3; Developed under: Dr. A.P.J. Abdul Kalam (Project Director); Development organization: ISRO (Indian Space Research Organisation ); Launch history: First test launch: 10 August 1979 (SLV-3 E1) — failed; First successful launch: 18 July 1980 — placed Rohini RS-1 satellite in orbit (India became 6th country to launch a satellite indigenously); Total launches: 4 (1979, 1980, 1981, 1983); The 1980 launch made India the first country in Asia to launch a satellite with its own rocket; Payload capacity: ~40 kg to Low Earth Orbit (LEO); Configuration: 4-stage solid- fuelled rocket; The SLV-3 demonstrated India's capability to develop indigenous space launch technology; About other launch vehicles: PSLV (Polar Satellite Launch Vehicle): Became operational in 1993 — first successful launch September 1994; ASLV (Augmented Satellite Launch Vehicle): Successor to SLV-3; first flight 1987 but first successful mission in 1992; GSLV (Geosynchronous Satellite Launch Vehicle): First launch 2001; used for heavier satellites; Chronological order of ISRO launch vehicles: SLV-3 (1980) → ASLV (1987/1992) → PSLV (1993/1994) → GSLV (2001).
Option (b) PSLV — Incorrect: The PSLV (Polar Satellite Launch Vehicle) became operational in 1994, not the 1980s; it was NOT used in the 1980s; the SLV-3 was India's indigenous launch vehicle of the 1980s. The candidate selected this incorrect option.
Option (c) ASLV — Incorrect: The ASLV (Augmented Satellite Launch Vehicle) was developed after SLV-3 — its first test flight was in 1987 and first successful mission was in 1992; while it partially overlaps with the 1980s, the vehicle specifically used in early 1980s Indian satellite launches was SLV-3.
Option (d) GSLV — Incorrect: The GSLV (Geosynchronous Satellite Launch Vehicle) first flew in April 2001 — it was developed much later and has no connection with 1980s satellite launches; SLV-3 is the correct answer for the 1980s launch vehicle.
SSC GD 2026 – 22 May 2026 Shift 1 · Defence organisations (DRDO, HAL, BEL)

Q43. In which year did the Government of India take over Ma zagon Dock?

  1. (a) 1972
  2. (b) 1968
  3. (c) 1960
  4. (d) 1964
Answer & solution

Answer: (c) 1960

Correct Answer: 1960 — Option (c)
The Government of India took over Mazagon Dock in 1960. About Mazagon Dock Shipbuilders Limited (MDL): Mazagon Dock is India's premier warship and submarine building yard; Located in Mumbai (Maharashtra); History: Originally established as a small dry dock in 1774 by the East India Company; Operated as a private shipyard for many years; In 1934, it was taken over by a British firm (Mackinnon Mackenzie & Co.); On August 11, 1960, the Indian government nationalized/took over Mazagon Dock, incorporating it as a government-owned company under the Ministry of Defence ; Current status: It is a Schedule 'A' Defence Public Sector Undertaking (DPSU) under the Ministry of Defence ; Listed on the stock exchanges (BSE and NSE) since 2020; Achievements: Built India's first frigate (INS Nilgiri ), first submarine (INS Shalki), P17A stealth frigates (Project 17A), Scorpene -class submarines (Project 75); Significance: MDL is critical to India's naval self-reliance under the 'Make in India' initiative in defence .
Option (a) 1972 — Incorrect: Mazagon Dock was taken over by the Government of India in 1960, not 1972; 1972 is not the correct year of nationalization of Mazagon Dock. The candidate selected this incorrect option.
Option (b) 1968 — Incorrect: The correct year of the Government of India taking over Mazagon Dock is 1960, not 1968.
Option (d) 1964 — Incorrect: Mazagon Dock was nationalized/taken over by the Government of India in 1960, not 1964.
SSC GD 2026 – 22 May 2026 Shift 2 · Indian space missions

Q44. Which of the following is the first Indian mission dedicated to observation of the Sun?

  1. (a) Hinode
  2. (b) Parker Solar Probe
  3. (c) Aditya L-1
  4. (d) SOHO
Answer & solution

Answer: (c) Aditya L-1

Correct Answer: Aditya L-1 — Option (c)
Aditya L-1 is the first Indian space mission dedicated to the observation of the Sun. About Aditya L-1: Launched by: ISRO (Indian Space Research Organisation ); Launch date: September 2, 2023, from Sriharikota (Satish Dhawan Space Centre) using PSLV-C57; Destination: Lagrange Point 1 (L1) — a gravitational equilibrium point about 1.5 million km from Earth (towards the Sun), where it reached on January 6, 2024; Significance: India's first solar observatory spacecraft; allows continuous, unobstructed observation of the Sun without any eclipses; Payloads (7 instruments): VELC (Visible Emission Line Coronagraph), SUIT (Solar Ultraviolet Imaging Telescope), ASPEX (Aditya Solar wind Particle Experiment), PAPA, SoLEXS , HEL1OS, MAG; Scientific objectives: Study the Sun's corona (outermost layer), solar wind, solar flares, Coronal Mass Ejections (CMEs), and solar magnetic field; Why Lagrange Point 1? At L1, the spacecraft can maintain its position relative to the Earth-Sun system with minimal fuel, enabling uninterrupted solar observation; About the name: 'Aditya' is a Sanskrit name for the Sun; 'L1' refers to the first Lagrange point.
Option (a) Hinode — Incorrect: Hinode (meaning 'sunrise' in Japanese) is a JAXA (Japan Aerospace Exploration Agency) solar observatory mission launched in 2006 — it is a JAPANESE mission, not Indian; it studies the Sun's magnetic field, corona, and solar wind.
Option (b) Parker Solar Probe — Incorrect: Parker Solar Probe is a NASA (USA) mission launched in August 2018 — it is an AMERICAN mission, not Indian; it is the closest spacecraft to the Sun ever sent, studying the solar corona and solar wind.
Option (d) SOHO — Incorrect: SOHO (Solar and Heliospheric Observatory) is a joint ESA-NASA (European Space Agency and NASA) mission launched in December 1995 — it is not an Indian mission; Aditya L-1 is India's first dedicated solar observation mission.
SSC GD 2026 – 21 May 2026 Shift 1 · Launch vehicles and satellites

Q45. The SLV-3 rocket used for India's first satellite launch was a ___-stage rocket.

  1. (a) 2
  2. (b) 3
  3. (c) 4
  4. (d) 5
Answer & solution

Answer: (c) 4

Correct Answer: 4 — Option (c)
The SLV-3 (Satellite Launch Vehicle-3) was a 4-stage, all-solid- fuelled rocket. Key facts about SLV-3: SLV-3 was India's first experimental satellite launch vehicle (SLV); It was developed by the Indian Space Research Organisation (ISRO) under the leadership of Dr. A.P.J. Abdul Kalam (who later served as India's 11th President); The '3' in SLV-3 refers to the payload capability (approximately 40 kg to Low Earth Orbit); Rocket stages: SLV-3 had 4 stages, all using solid propellants (no liquid stages); Stage 1 — Largest solid motor providing main thrust; Stage 2 — Second solid motor; Stage 3 — Third solid motor; Stage 4 — Fourth solid motor (uppermost stage with payload); Flight history: First successful launch: July 18, 1980 — SLV-3 E2 successfully placed the Rohini satellite (RS-1) into orbit; This made India the 6th country in the world to develop a launch vehicle and put a satellite into orbit; 3 more flights followed; Significance: SLV-3 was the foundation for India's subsequent rocket programs — ASLV, PSLV, and GSLV.
Option (a) 2 — Incorrect: SLV-3 was a 4-stage rocket, not a 2-stage rocket; a 2-stage configuration would not have provided sufficient velocity to achieve orbital insertion for the Rohini satellite.
Option (b) 3 — Incorrect: SLV-3 was a 4-stage solid-propellant rocket, not a 3-stage rocket; the PSLV (Polar Satellite Launch Vehicle, which came later) has 4 stages with alternating solid and liquid stages.
Option (d) 5 — Incorrect: SLV-3 was a 4-stage rocket, not a 5-stage rocket; no Indian orbital launch vehicle has used 5 stages.
SSC GD 2026 – 21 May 2026 Shift 3 · ISRO - history and centres

Q46. Which of the following statements about New Space India Limited (NSIL) is correct?
I. It is a private sector venture.
II. It is involved in the manufacture of various types and categories of satellites and in-orbit delivery work.

  1. (a) Only I
  2. (b) Only II
  3. (c) Both I and II
  4. (d) Neither I nor II
Answer & solution

Answer: (b) Only II

Correct Answer: Only II — Option (b)
Only Statement II is correct about New Space India Limited (NSIL). Statement I Analysis — 'It is a private sector venture' (INCORRECT): NSIL is NOT a private sector company; it is a Central Public Sector Enterprise (CPSE) — a Government of India undertaking; It was incorporated on March 6, 2019 under the Companies Act, 2013, as a wholly owned Government of India company under the Department of Space (DoS); It is India's second space public sector undertaking after Antrix Corporation; Statement II Analysis — 'It is involved in the manufacture of various types and categories of satellites and in-orbit delivery work' (CORRECT): NSIL is involved in: Manufacturing of Small Satellite Launch Vehicles (SSLVs) and PSLV rockets through Indian industry; Building operational communication satellites (like GSAT series); Providing launch services for commercial customers; Technology transfer from ISRO to Indian industry; In-orbit delivery of satellites as a commercial service; Key roles of NSIL: Demand-driven space activities; technology absorption by Indian industry; commercial exploitation of ISRO's research; NewSpace growth in India.
Option (a) Only I — Incorrect: Statement I ('It is a private sector venture') is WRONG — NSIL is a Government of India CPSE (Central Public Sector Enterprise), not a private sector company; Statement II is the correct statement about NSIL.
Option (c) Both I and II — Incorrect: Statement I is incorrect (NSIL is a government company, not private); only Statement II (involvement in satellite manufacture and in-orbit delivery) is correct; therefore 'Both I and II' cannot be the answer. The candidate selected this incorrect option.
Option (d) Neither I nor II — Incorrect: Statement II IS correct — NSIL is indeed involved in the manufacture of various categories of satellites and in-orbit delivery work; 'Neither I nor II' would mean both statements are wrong, which is incorrect.
SSC GD 2026 – 20 May 2026 Shift 2 · Indian space missions

Q47. Gaganyaan mission is a _____ day human spaceflight mission, in which the crew will be launched into orbit and safely brought back to Earth.

  1. (a) 3
  2. (b) 5
  3. (c) 7
  4. (d) 9
Answer & solution

Answer: (a) 3

Correct Answer: 3 days — Option (a)
The Gaganyaan mission is India's first human spaceflight programme planned as a 3-day mission. Key details of Gaganyaan : Developed by ISRO (Indian Space Research Organisation ); The crew of Indian astronauts (called Gaganauts or Vyomanauts) will be launched into a 400 km low Earth orbit (LEO) for approximately 3 days; The crew module will then re-enter the atmosphere and splash down in the Bay of Bengal near the Andaman and Nicobar Islands; The mission will be launched on the LVM3 (Launch Vehicle Mark 3), formerly known as GSLV MK III; Four Indian Air Force (IAF) pilots have been selected as astronaut candidates: Group Captain Prashanth Balakrishnan Nair, Group Captain Ajit Krishnan, Group Captain Angad Pratap, and Wing Commander Shubhanshu Shukla; The Gaganyaan mission, if successful, will make India the fourth country after Russia, USA, and China to independently send humans to space.
Option (b) 5 days — Incorrect: The Gaganyaan mission is planned for 3 days (not 5 days) in low Earth orbit; 5 days is not the planned duration for this mission.
Option (c) 7 days — Incorrect: The Gaganyaan mission has a planned duration of 3 days (approximately 72 hours) in low Earth orbit, not 7 days.
Option (d) 9 days — Incorrect: The Gaganyaan mission is a 3-day mission, not a 9-day mission; 9 days would be more typical of longer crewed missions to space stations, not the initial Gaganyaan demonstration mission.
SSC GD 2026 – 19 May 2026 Shift 1 · ISRO - history and centres

Q48. In which year did INCOSPAR (Indian National Committee for Space Research) evolve into ISRO (Indian Space Research Organisation )?

  1. (a) 1962
  2. (b) 1969
  3. (c) 1972
  4. (d) 1974
Answer & solution

Answer: (b) 1969

Correct Answer: 1969 — Option (b)
ISRO (Indian Space Research Organisation ) was formally established on August 15, 1969, when INCOSPAR (Indian National Committee for Space Research) was reorganised and expanded into ISRO. INCOSPAR was established in 1962 under the Department of Atomic Energy, with Dr. Vikram Sarabhai as its chairman, following India's first rocket launch from Thumba Equatorial Rocket Launching Station (TERLS) in Kerala. ISRO was placed under the newly created Department of Space in 1972, and Dr. Vikram Sarabhai is recognised as the father of India's space programme . Today, ISRO is one of the world's leading space agencies, with achievements including Chandrayaan missions, Mangalyaan, Aditya-L1, and the PSLV launch vehicle.
Option (a) 1962 — Incorrect: 1962 was the year INCOSPAR was established (not when it became ISRO). ISRO came into existence in 1969.
Option (c) 1972 — Incorrect: 1972 was the year ISRO was placed under the newly created Department of Space; ISRO itself was established in 1969.
Option (d) 1974 — Incorrect: 1974 is not related to the establishment of ISRO. India's first nuclear test (Smiling Buddha) was conducted in 1974, but ISRO was established in 1969.
SSC GD 2026 – 19 May 2026 Shift 3 · ISRO - history and centres

Q49. The Indian Institute of Space Science and Technology (IIST) is located in _____.

  1. (a) Kochi
  2. (b) Nagpur
  3. (c) New Delhi
  4. (d) Thiruvananthapuram
Answer & solution

Answer: (d) Thiruvananthapuram

Correct Answer: Thiruvananthapuram — Option (d)
The Indian Institute of Space Science and Technology (IIST) is located in Thiruvananthapuram (Trivandrum), Kerala. IIST was established in 2007 by the Indian Space Research Organisation (ISRO) under the Department of Space, Government of India. It is India's first and only dedicated space university. IIST offers undergraduate, postgraduate, and doctoral programmes in space science, space technology, and space applications. Students who graduate from IIST are typically inducted into ISRO to work on India's space programme . The institute is situated near ISRO's Vikram Sarabhai Space Centre (VSSC), which is ISRO's largest centre and the primary centre for launch vehicle development.
Option (a) Kochi — Incorrect: Kochi (Kerala) hosts other ISRO facilities and institutions, but IIST is specifically located in Thiruvananthapuram, not Kochi.
Option (b) Nagpur — Incorrect: Nagpur (Maharashtra) does not host IIST; the Indian Institute of Space Science and Technology is in Thiruvananthapuram, Kerala.
Option (c) New Delhi — Incorrect: New Delhi hosts various government ministries and institutions, but IIST is located in Thiruvananthapuram, close to ISRO's Vikram Sarabhai Space Centre.
SSC GD 2026 – 18 May 2026 Shift 2 · Launch vehicles and satellites

Q50. What is the gross weight of ISRO's PSLV-XL Configuration?

  1. (a) 120 tonnes
  2. (b) 1040 tonnes
  3. (c) 320 tonnes
  4. (d) 560 tonnes
Answer & solution

Answer: (c) 320 tonnes

Correct Answer: 320 tonnes — Option (c)
The PSLV-XL (Polar Satellite Launch Vehicle — Extra Large) is the most powerful variant of ISRO's workhorse PSLV rocket. Its gross lift-off mass (gross weight at launch) is approximately 320 tonnes . The PSLV-XL uses six strap-on solid rocket boosters (each 12 metres long, 1 metre diameter) which provide additional thrust during the initial phase of launch, making it more powerful than the standard PSLV. The PSLV-XL can carry heavier payloads to higher orbits. Notable missions using PSLV-XL include Chandrayaan-1 (2008), Mars Orbiter Mission/Mangalyaan (2013), IRNSS-1 satellites, and Aditya-L1 (India's first solar mission, 2023).
Option (a) 120 tonnes — Incorrect: 120 tonnes is significantly less than the actual gross weight of PSLV-XL; the correct gross lift-off mass is approximately 320 tonnes .
Option (b) 1040 tonnes — Incorrect: 1040 tonnes is much heavier than PSLV-XL; this figure is closer to the gross weight of India's LVM3 (Launch Vehicle Mark-3), formerly known as GSLV Mk III (~640 tonnes ).
Option (d) 560 tonnes — Incorrect: 560 tonnes exceeds the actual gross weight of PSLV-XL (320 tonnes ); it is close to the weight of heavier launch vehicles like GSLV Mk II (~414 tonnes ) or LVM3.
SSC GD 2026 – 18 May 2026 Shift 2 · Indian space missions

Q51. Which of the following discoveries has been made with AstroSat ?
I. The detection of ultraviolet emissions emanating from remote galaxies.
II. The polarisation of X-rays in proximate supernova remnants.

  1. (a) Only I
  2. (b) Only II
  3. (c) Both I and II
  4. (d) Neither I nor II
Answer & solution

Answer: (c) Both I and II

Correct Answer: Both I and II — Option (c)
AstroSat is India's first dedicated multi-wavelength space observatory launched by ISRO on September 28, 2015. It carries five scientific payloads covering ultraviolet, optical, and X-ray wavelengths simultaneously. Both discoveries mentioned have been made using AstroSat : Statement I — AstroSat detected UV emissions from distant/remote galaxies using its UVIT (Ultra-Violet Imaging Telescope), including the detection of extreme ultraviolet (Lyman continuum) photons from ancient galaxies; Statement II — AstroSat detected X-ray polarisation in supernova remnants (such as in Crab Nebula and Cassiopeia A) using its CZT Imager and SXT instruments. These multi-wavelength observations make AstroSat uniquely capable of conducting comprehensive astronomical studies.
Option (a) Only I — Incorrect: AstroSat has made both the UV emission detection (Statement I) AND X-ray polarisation discoveries (Statement II), so 'Only I' is incomplete.
Option (b) Only II — Incorrect: AstroSat has made discoveries in both UV (Statement I) and X-ray polarisation (Statement II) domains; 'Only II' is incomplete.
Option (d) Neither I nor II — Incorrect: Both statements describe real discoveries made with AstroSat ; this option is entirely incorrect.
SSC GD 2026 – 9 May 2026 Shift 1 · Indian space missions

Q52. Chandrayaan-1 mission ended after contact with the spacecraft was lost in _____.

  1. (a) 2009
  2. (b) 2013
  3. (c) 2017
  4. (d) 2014
Answer & solution

Answer: (a) 2009

Correct Answer: 2009 — Option (a)
India's first lunar mission, Chandrayaan-1, was launched by ISRO on October 22, 2008. Contact with the spacecraft was lost on August 29, 2009, after it had operated for 312 days (about 10 months) in lunar orbit — achieving most of its scientific objectives. Despite the premature end, Chandrayaan-1 was a great success: it confirmed the presence of water molecules on the Moon's surface (a major discovery in collaboration with NASA's Moon Mineralogy Mapper — M3 instrument), produced the first complete map of the Moon's chemical composition, and demonstrated India's capabilities in space exploration.
Option (b) 2013 — Incorrect: Chandrayaan-1 lost contact in 2009, not 2013. India's Mars Orbiter Mission (Mangalyaan) was launched in 2013.
Option (c) 2017 — Incorrect: Contact with Chandrayaan-1 was lost in 2009, not 2017.
Option (d) 2014 — Incorrect: The mission ended in 2009 when contact was lost; 2014 is not the correct year.
SSC GD 2026 – 9 May 2026 Shift 1 · Missiles and weapon systems

Q53. The S-400 missile defence system is developed by which country?

  1. (a) Russia
  2. (b) USA
  3. (c) China
  4. (d) Germany
Answer & solution

Answer: (a) Russia

Correct Answer: Russia — Option (a)
The S-400 Triumf (NATO designation: SA-21 Growler) is a long-range surface-to-air missile (SAM) defence system developed by Russia's Almaz-Antey defence corporation. It is one of the most advanced and capable air defence systems in the world, capable of engaging aircraft, drones, cruise missiles, and ballistic missiles at ranges up to 400 km and altitudes up to 30 km. India signed a ₹35,000 crore deal with Russia to purchase five S-400 regiments in 2018, despite pressure from the US (CAATSA sanctions). India started receiving S-400 deliveries from Russia in 2021–22.
Option (b) USA — Incorrect: The US equivalent is the Patriot missile system (PAC-3); the S-400 is a Russian-made system.
Option (c) China — Incorrect: China has developed its own HQ-9 system and has purchased S-400 from Russia, but China did not develop the S-400.
Option (d) Germany — Incorrect: Germany is not the developer of the S-400; it is a Russian-developed surface-to-air missile defence system.
SSC GD 2026 – 9 May 2026 Shift 3 · Indian space missions

Q54. In which of the following years did India enter the space age when the first Indian satellite was launched?

  1. (a) 1961
  2. (b) 1971
  3. (c) 1975
  4. (d) 1989
Answer & solution

Answer: (c) 1975

Correct Answer: 1975 — Option (c)
India entered the space age on April 19, 1975, when Aryabhata — India's first satellite — was successfully launched. It was launched by the Soviet Union using a Cosmos-3M rocket from the Kapustin Yar launch site in Russia. Aryabhata was named after the famous Indian mathematician and astronomer Aryabhata (476–550 CE). The satellite was built by ISRO (Indian Space Research Organisation ) and was primarily experimental in nature, conducting experiments in X-ray astronomy, aeronomics , and solar physics. Although Aryabhata lost contact after 4 days due to a power failure, it successfully placed India on the global space map.
Option (a) 1961 — Incorrect: In 1961, INCOSPAR (Indian National Committee for Space Research — the predecessor to ISRO) was established; India did not launch its first satellite in 1961.
Option (b) 1971 — Incorrect: ISRO was formally established in 1969; India's first satellite (Aryabhata) was launched in 1975, not 1971.
Option (d) 1989 — Incorrect: By 1989, India had launched multiple satellites; the first Indian satellite (Aryabhata) was launched in 1975.
SSC GD 2026 – 9 May 2026 Shift 3 · Space tourism and commercial spaceflight

Q55. Who launched the world's first rocket with a fully 3D-printed engine in 2024?

  1. (a) Agnikul
  2. (b) SpaceX
  3. (c) Blue Origin
  4. (d) Skyroot Aerospace
Answer & solution

Answer: (a) Agnikul

Correct Answer: Agnikul — Option (a)
Agnikul Cosmos, an Indian space startup based in Chennai, launched Agnibaan SOrTeD (Sub-Orbital Technology Demonstrator) on May 30, 2024, from the Sriharikota space centre — making it the world's first rocket powered by a fully 3D-printed engine ( Agnilet ). The Agnilet engine was entirely 3D-printed as a single piece, using no welds, bolts, or rivets. This was a major technological achievement in space manufacturing, demonstrating the potential of additive manufacturing (3D printing) for rocket engines. Agnikul Cosmos also built the world's first private launchpad (Dhanush) at SDSC SHAR, Sriharikota .
Option (b) SpaceX — Incorrect: SpaceX is the American rocket company founded by Elon Musk; it did not launch the world's first fully 3D-printed engine rocket. That achievement belongs to Agnikul Cosmos (India).
Option (c) Blue Origin — Incorrect: Blue Origin is the rocket company founded by Jeff Bezos; it was not responsible for launching the world's first fully 3D-printed engine rocket.
Option (d) Skyroot Aerospace — Incorrect: Skyroot Aerospace is another Indian space startup that launched Vikram-S (India's first private rocket) in 2022; but the 3D-printed engine rocket achievement belongs to Agnikul Cosmos.
SSC GD 2026 – 5 May 2026 Shift 2 · Launch vehicles and satellites

Q56. Which Indian satellite helped in monitoring cyclones like Hudhud and Phailin?

  1. (a) INSAT-3D
  2. (b) Cartosat-1
  3. (c) GSAT-7
  4. (d) RISAT-2
Answer & solution

Answer: (a) INSAT-3D

Correct Answer: INSAT-3D — Option (a)
INSAT-3D is an advanced meteorological satellite launched by ISRO in 2013. It played a crucial role in monitoring and tracking severe cyclones like Phailin (2013) and Hudhud (2014) over the Bay of Bengal. INSAT-3D carries an Imager and a Sounder payload that provide real-time data on atmospheric temperature, humidity profiles, and cloud imagery — enabling the India Meteorological Department (IMD) to issue timely cyclone warnings.
Option (b) Cartosat-1 — Incorrect: Cartosat-1 is a remote sensing satellite for cartographic applications (mapping and terrain modeling), not meteorology or cyclone monitoring.
Option (c) GSAT-7 — Incorrect: GSAT-7 (Rukmini) is a military communication satellite used by the Indian Navy; it is not designed for cyclone monitoring.
Option (d) RISAT-2 — Incorrect: RISAT-2 is a radar imaging satellite primarily used for border surveillance and disaster monitoring; it is not a meteorological satellite for cyclone tracking.
SSC GD 2026 – 5 May 2026 Shift 3 · Launch vehicles and satellites

Q57. Which ISRO satellite supports the Indian Navy's communication requirements?

  1. (a) GSAT-12
  2. (b) GSAT-7
  3. (c) GSAT-29
  4. (d) Cartosat-2
Answer & solution

Answer: (b) GSAT-7

Correct Answer: GSAT-7 — Option (b)
GSAT-7, also known as 'Rukmini', is an advanced multi-band military communication satellite launched by ISRO in August 2013. It is exclusively used by the Indian Navy to provide communication services across the Indian Ocean Region (IOR). GSAT-7 supports communication needs in UHF, C-band, and Ku-band frequencies, enabling real-time connectivity between naval vessels at sea, aircraft, and land-based installations. It significantly enhanced the Indian Navy's network-centric warfare capabilities.
Option (a) GSAT-12 — Incorrect: GSAT-12 is a civil communication satellite for social applications (education, telemedicine); it does not serve the Indian Navy.
Option (c) GSAT-29 — Incorrect: GSAT-29 is a high-throughput communication satellite for civilian broadband services in northeastern India and Jammu & Kashmir; it is not a military/naval satellite.
Option (d) Cartosat-2 — Incorrect: Cartosat-2 is a remote sensing/earth observation satellite used for cartographic and mapping applications; it does not provide communication services for the Navy.
SSC GD 2026 – 4 May 2026 Shift 2 · Indian space missions

Q58. Which Indian solar mission started regular scientific observations using the SUIT instrument and released its first data set at the beginning of 2025?

  1. (a) AstroSat-2
  2. (b) Aditya-L1
  3. (c) Chandrayaan-3
  4. (d) XPoSat
Answer & solution

Answer: (b) Aditya-L1

Correct Answer: Aditya-L1 — Option (b)
Aditya-L1, India's first solar observation mission launched by ISRO in September 2023, carries the Solar Ultraviolet Imaging Telescope (SUIT) as one of its key payloads. The mission reached the Sun-Earth Lagrange Point 1 (L1) in January 2024 and commenced regular scientific observations. In early 2025, Aditya-L1 released its first science data set from the SUIT instrument, which studies the solar photosphere and chromosphere.
Option (a) AstroSat-2 — Incorrect: AstroSat-2 has not been launched yet; AstroSat-1 (2015) is a multi-wavelength space observatory but does not carry SUIT.
Option (c) Chandrayaan-3 — Incorrect: Chandrayaan-3 is a lunar mission, not a solar mission.
Option (d) XPoSat — Incorrect: XPoSat (X-ray Polarimeter Satellite) studies X-ray sources in the universe, not the Sun, and does not carry the SUIT instrument.
SSC GD 2026 – 4 May 2026 Shift 2 · Indian space missions

Q59. Despite the lander's failure, what was significant about the Chandrayaan-2 mission?

  1. (a) It studied Venus
  2. (b) Its orbiter continues to send data
  3. (c) It carried astronauts
  4. (d) It was India's first Mars mission
Answer & solution

Answer: (b) Its orbiter continues to send data

Correct Answer: Its orbiter continues to send data — Option (b)
Although the Vikram lander of Chandrayaan-2 crash-landed on the Moon's surface in September 2019, the mission was not a complete failure. The Chandrayaan-2 orbiter successfully entered lunar orbit and has been continuously sending valuable scientific data about the Moon's surface, exosphere, and minerals. The orbiter was designed to function for 7 years and carries 8 scientific payloads.
Option (a) It studied Venus — Incorrect: Chandrayaan-2 is a lunar mission; it has nothing to do with Venus.
Option (c) It carried astronauts — Incorrect: Chandrayaan-2 was an unmanned robotic mission; no astronauts were carried.
Option (d) It was India's first Mars mission — Incorrect: India's first Mars mission was Mangalyaan (MOM-1), launched in 2013.
SSC GD 2026 – 30 April 2026 Shift 3 · ISRO - history and centres

Q60. What capability does Project NETRA provide to ISRO?

  1. (a) Deep-space communication
  2. (b) Space debris tracking and situational awareness
  3. (c) Human-rated life support
  4. (d) Lunar landing navigation
Answer & solution

Answer: (b) Space debris tracking and situational awareness

Correct Answer: Space debris tracking and situational awareness — Option (b)
Project NETRA (Network for Space Objects Tracking and Analysis) is ISRO's initiative to monitor and track space debris, satellites, and other objects in Earth's orbit. It provides Space Situational Awareness (SSA) — the ability to detect, track, and catalogue objects in space to protect Indian assets in orbit from potential collisions with debris.
Option (a) Deep-space communication — Incorrect: NETRA is focused on Earth orbit tracking, not deep-space communication.
Option (c) Human-rated life support — Incorrect: Life support systems are part of the Gaganyaan human spaceflight program, not NETRA.
Option (d) Lunar landing navigation — Incorrect: Lunar landing navigation was associated with Chandrayaan-3, not NETRA.
SSC GD 2026 – 30 April 2026 Shift 3 · Indian space missions

Q61. India wants to explore Venus's thick atmosphere and greenhouse effect. Which mission is planned?

  1. (a) LUPEX
  2. (b) Shukrayaan (Venus Orbiter)
  3. (c) Chandrayaan-4
  4. (d) MOM-2
Answer & solution

Answer: (b) Shukrayaan (Venus Orbiter)

Correct Answer: Shukrayaan (Venus Orbiter) — Option (b)
Shukrayaan-1 (also called Venus Orbiter Mission) is ISRO's planned mission to study Venus, including its thick atmosphere, clouds, and greenhouse effect. 'Shukra' is the Sanskrit name for Venus. The mission aims to study the Venusian atmosphere, surface, and subsurface using an orbiter spacecraft.
Option (a) LUPEX — Incorrect: LUPEX (Lunar Polar Exploration mission) is a joint ISRO-JAXA mission to explore water ice at the Moon's polar regions.
Option (c) Chandrayaan-4 — Incorrect: Chandrayaan-4 is India's planned lunar sample return mission, not a Venus mission.
Option (d) MOM-2 — Incorrect: MOM-2 (Mars Orbiter Mission 2) is ISRO's planned second mission to Mars, not Venus.
SSC GD 2026 – 29 April 2026 Shift 2 · International space missions and agencies

Q62. Which telescope provided the first direct image of a black hole?

  1. (a) Hubble
  2. (b) Event Horizon Telescope
  3. (c) Spitzer
  4. (d) Kepler
Answer & solution

Answer: (b) Event Horizon Telescope

Correct Answer: Event Horizon Telescope — Option (b)
The Event Horizon Telescope (EHT) provided the first-ever direct image of a black hole, released on April 10, 2019. Key facts: The image captured was of the supermassive black hole M87* (located at the center of the Messier 87 galaxy, about 55 million light-years from Earth); The EHT is not a single telescope but a network of synchronized radio telescopes spread across the globe (in Hawaii, Arizona, Chile, Spain, Mexico, and the South Pole), forming a virtual telescope the size of Earth; The image showed the black hole's shadow (event horizon) surrounded by a bright ring of superheated plasma; In May 2022, the EHT also released the first image of Sagittarius A* ( Sgr A*) — the supermassive black hole at the center of our own Milky Way galaxy; The EHT collaboration received the Breakthrough Prize in Fundamental Physics in 2019 for this achievement.
Option (a) Hubble — Incorrect: The Hubble Space Telescope is an optical/ultraviolet/infrared telescope that has made many groundbreaking astronomical discoveries; however, it was NOT the telescope that provided the first direct image of a black hole — that was achieved by the Event Horizon Telescope in 2019.
Option (c) Spitzer — Incorrect: The Spitzer Space Telescope (NASA, decommissioned in 2020) was an infrared space observatory; while it contributed to our knowledge of stars, galaxies, and exoplanets, it did not provide the first direct image of a black hole — the EHT did in 2019.
Option (d) Kepler — Incorrect: The Kepler Space Telescope (NASA, operated 2009-2018) was designed to find exoplanets using the transit method; it discovered thousands of exoplanets but was not involved in imaging black holes. The candidate selected this incorrect option.
SSC GD 2026 – 28 April 2026 Shift 3 · Launch vehicles and satellites

Q63. Which Indian rocket is called 'Fat Boy'?

  1. (a) PSLV
  2. (b) GSLV MK III
  3. (c) SSLV
  4. (d) ASLV
Answer & solution

Answer: (b) GSLV MK III

Correct Answer: GSLV MK III — Option (b)
GSLV MK III (Geosynchronous Satellite Launch Vehicle Mark III), now officially renamed LVM3 (Launch Vehicle Mark 3), is nicknamed 'Fat Boy' due to its large, wide, and bulky appearance compared to other Indian rockets. Key features of GSLV MK III: It is India's heaviest and most powerful operational rocket; Height: 43.5 metres ; Liftoff mass: 640 tonnes ; Can carry payloads of up to 4,000 kg to Geostationary Transfer Orbit (GTO) and up to 10,000 kg to Low Earth Orbit (LEO); It uses indigenous cryogenic engine (CE-20) making India self-reliant in cryogenic technology; Notable missions: Chandrayaan-2 (2019), OneWeb constellation satellites, Chandrayaan-3 (2023). GSLV MK III was also the rocket selected for India's upcoming Gaganyaan human spaceflight mission.
Option (a) PSLV — Incorrect: PSLV (Polar Satellite Launch Vehicle) is India's most reliable and workhorse rocket, known for its versatility; it is not called 'Fat Boy' — GSLV MK III has this nickname due to its bulky appearance.
Option (c) SSLV — Incorrect: SSLV (Small Satellite Launch Vehicle) is India's newest and smallest orbital rocket designed for launching small satellites quickly and cost-effectively; it is not called 'Fat Boy'.
Option (d) ASLV — Incorrect: ASLV (Augmented Satellite Launch Vehicle) was an early ISRO rocket that was retired in 1994; it was not called 'Fat Boy' — this nickname belongs to GSLV MK III.
SSC MTS 2025 – 20 February 2026 Shift 1 · Indian space missions

Q64. The Vikram lander and Pragyan rover is associated with _____.

  1. (a) Chandrayaan-1
  2. (b) Chandrayaan-3
  3. (c) Mangalyaan
  4. (d) Aditya L-1
Answer & solution

Answer: (b) Chandrayaan-3

Correct Answer: Chandrayaan-3 (Option 2)
The Vikram lander and Pragyan rover were part of ISRO's Chandrayaan-3 mission, launched on July 14, 2023. On August 23, 2023, Chandrayaan-3 made a historic soft landing near the Moon's south polar region, making India the first country to land near the lunar south pole and the fourth country overall to achieve a lunar soft landing.
Why other options are wrong:
Option 1 – Chandrayaan-1 (2008) was an orbiter mission; no lander or rover.
Option 3 – Mangalyaan (Mars Orbiter Mission, 2013) was a Mars orbiter; no lander.
Option 4 – Aditya L-1 (2023) is a solar observation mission sent to the Sun-Earth L1 Lagrange point.
SSC MTS 2025 – 20 February 2026 Shift 2 · Missiles and weapon systems

Q65. Which of the following is the India's first ever anti-satellite missile test?

  1. (a) Mission Shakti
  2. (b) Mission Indradhanush
  3. (c) Mission Shanti
  4. (d) Mission Agni
Answer & solution

Answer: (a) Mission Shakti

Correct Answer: Mission Shakti (Option 1)
Mission Shakti was India's first and only Anti-Satellite (ASAT) missile test, conducted on March 27, 2019. India used a ground-based Ballistic Missile Defence (BMD) interceptor to destroy a live Indian satellite ( Microsat -R) in Low Earth Orbit at approximately 300 km altitude. This made India the 4th country (after the USA, Russia, and China) to successfully demonstrate ASAT capability.
Why other options are wrong:
Option 2 – Mission Indradhanush is related to universal immunization programme , not an ASAT test.
Option 3 – Mission Shanti is not an established ASAT or space mission name.
Option 4 – Mission Agni refers to India's Agni ballistic missile program, not an ASAT test.
RRB JE CBT-1 2025-26 – 20 February 2026 · Missiles and weapon systems

Q66. Which missile system is being developed under Project Kusha to enhance India's air defence capabilities?

  1. (a) BrahMos
  2. (b) S-400
  3. (c) MICA
  4. (d) Extended Range Air Defence System
Answer & solution

Answer: (d) Extended Range Air Defence System

Option 4 is correct: Extended Range Air Defence System (ERADS).
Project Kusha aims to develop an advanced missile system to boost India's air defence capabilities.
ERADS is specifically designed to detect and destroy hostile targets at longer ranges.
BrahMos, S-400, and MICA are existing missile systems but not developed under Project Kusha.
Hence, the missile system under Project Kusha enhancing India's air defence is ERADS.
Final answer: Option 4
SSC MTS 2025 – 19 February 2026 Shift 1 · Missiles and weapon systems

Q67. 'HTT-40', developed by HAL is a _____.

  1. (a) Trainer aircraft
  2. (b) Cargo helicopter
  3. (c) Light attack aircraft
  4. (d) Passenger aircraft
Answer & solution

Answer: (a) Trainer aircraft

The correct answer is option 1.
HTT-40 (Hindustan Turbo Trainer-40) is a basic trainer aircraft developed by Hindustan Aeronautics Limited (HAL) for the Indian Air Force. It is designed to train military pilots in basic flying skills. The aircraft completed its maiden flight in 2016 and is intended to replace the ageing HPT-32 Deepak trainer aircraft.
Option 2 is incorrect: HTT-40 is a fixed-wing trainer aircraft, not a cargo helicopter.
Option 3 is incorrect: HTT-40 is a trainer aircraft, not a light attack aircraft. HAL's light combat aircraft is the Tejas.
Option 4 is incorrect: HTT-40 is a military trainer aircraft, not a passenger aircraft.
SSC MTS 2025 – 19 February 2026 Shift 1 · Science and technology missions and schemes

Q68. The National Green Hydrogen Mission in India aims to achieve a targeted production capacity of 5 million tonnes per annum green hydrogen by _____.

  1. (a) 2027
  2. (b) 2030
  3. (c) 2035
  4. (d) 2047
Answer & solution

Answer: (b) 2030

The correct answer is option 2.
India's National Green Hydrogen Mission, approved in January 2023, aims to achieve a targeted green hydrogen production capacity of at least 5 million metric tonnes (MMT) per annum by 2030. The mission also aims to add about 125 GW of renewable energy capacity and create over 6 lakh jobs by 2030.
Option 1 is incorrect: 2027 is not the target year for 5 MMT production capacity under this mission.
Option 3 is incorrect: 2035 is not the stated target year.
Option 4 is incorrect: 2047 is India's vision for becoming a developed nation (Viksit Bharat); the green hydrogen target is specifically set for 2030.
SSC MTS 2025 – 19 February 2026 Shift 2 · Nuclear programme and institutions

Q69. As per Department of Atomic Energy, India has constituted _____ of the global total thorium reserves.

  1. (a) 31%
  2. (b) 21%
  3. (c) 44%
  4. (d) 54%
Answer & solution

Answer: (b) 21%

The correct answer is option 2.
As per the Department of Atomic Energy, India holds approximately 21% of the world's total thorium reserves (around 846,477 tonnes), making it one of the largest thorium-reserve nations in the world. India's thorium deposits are found mainly along the monazite sands on the Kerala coast, Tamil Nadu, Andhra Pradesh, and Odisha. India's Three-Stage Nuclear Programme aims to utilise these thorium reserves for energy production.
Option 1 is incorrect: 31% is not the correct figure for India's share of global thorium reserves.
Option 3 is incorrect: 44% significantly overstates India's share.
Option 4 is incorrect: 54% is an overestimation of India's thorium reserves share.
SSC MTS 2025 – 19 February 2026 Shift 3 · Launch vehicles and satellites

Q70. What is the lift off mass of ISRO's GSLV Mk II?

  1. (a) 420 tonnes
  2. (b) 120 tonnes
  3. (c) 840 tonnes
  4. (d) 1020 tonnes
Answer & solution

Answer: (a) 420 tonnes

Correct Answer: 420 tonnes (Option 1)
ISRO's GSLV Mk II (Geosynchronous Satellite Launch Vehicle Mark II) has a lift-off mass of approximately 414.75 tonnes , commonly rounded to about 420 tonnes . It is a three-stage rocket capable of placing 2,500 kg satellites into Geostationary Transfer Orbit (GTO).
Why other options are wrong:
Option 2 – 120 tonnes is far too low for GSLV Mk II.
Option 3 – 840 tonnes is approximately the mass of LVM3 (GSLV Mk III), not Mk II.
Option 4 – 1020 tonnes is an entirely incorrect figure for any ISRO launch vehicle.
SSC MTS 2025 – 18 February 2026 Shift 1 · Launch vehicles and satellites

Q71. GSAT-18, built by ISRO, aims at providing which type of services for the country?

  1. (a) Defence
  2. (b) Navigation
  3. (c) Telecommunications
  4. (d) Agriculture
Answer & solution

Answer: (c) Telecommunications

GSAT-18 is a communications satellite built by ISRO and launched in 2016, aimed at providing telecommunications services including DTH television, VSAT services, and telephone communications. GSAT satellites are part of India's communication satellite programme . Defence navigation is served by other dedicated satellites; agriculture monitoring uses remote sensing satellites.
SSC MTS 2025 – 18 February 2026 Shift 3 · Indian space missions

Q72. Which of the following space mission of India was credited for reviving interest about presence of water on Moon?

  1. (a) Chandrayaan -I
  2. (b) Chandrayaan -II
  3. (c) Chandrayaan -III
  4. (d) Aditya L-1
Answer & solution

Answer: (a) Chandrayaan -I

The correct answer is option 1.
Chandrayaan -I (2008) was India's first lunar mission. Its Moon Impact Probe (MIP) and NASA's Moon Mineralogy Mapper (M3) instrument on board detected water molecules (hydroxyl and water ice) in the polar regions of the Moon. This discovery revived global scientific interest in the presence of water on the Moon and was considered a landmark finding.
Option 2 is incorrect: Chandrayaan -II (2019) was the follow-up mission; though it advanced lunar exploration, the groundbreaking water discovery was credited to Chandrayaan -I.
Option 3 is incorrect: Chandrayaan -III (2023) successfully landed on the Moon's south pole but came after the water discovery was already established by Chandrayaan -I.
Option 4 is incorrect: Aditya L-1 is India's solar observation mission launched in 2023 to study the Sun; it has no connection to Moon water discovery.
SSC MTS 2025 – 17 February 2026 Shift 2 · Indian space missions

Q73. India's first success in launching a satellite using an indigenous vehicle came in _____.

  1. (a) 1955
  2. (b) 1965
  3. (c) 1972
  4. (d) 1980
Answer & solution

Answer: (d) 1980

India's first success in launching a satellite using an indigenous vehicle came in 1980. India's SLV-3 (Satellite Launch Vehicle) successfully placed the Rohini satellite (RS-1) into orbit on 18 July 1980. The earlier SLV-3 attempt in 1979 failed. 1955, 1965, and 1972 are incorrect.
SSC MTS 2025 – 13 February 2026 Shift 1 · ISRO - history and centres

Q74. The Indian Institute of Space Science and Technology was founded in which of the following year?

  1. (a) 1972
  2. (b) 1995
  3. (c) 2007
  4. (d) 2014
Answer & solution

Answer: (c) 2007

Correct Answer: Option 3 – 2007
The Indian Institute of Space Science and Technology (IIST) was established in 2007 in Thiruvananthapuram, Kerala. It is the first university in Asia dedicated to space science and technology, functioning under the Department of Space, Government of India. IIST offers undergraduate, postgraduate, and doctoral programmes in space-related fields.
Why other options are wrong:
Option 1 (1972): IIST was not established in 1972.
Option 2 (1995): IIST was not established in 1995.
Option 4 (2014): IIST was established in 2007, not 2014.
SSC MTS 2025 – 13 February 2026 Shift 3 · ISRO - history and centres

Q75. In which of the following year, the Department of Space was established in India?

  1. (a) 1961
  2. (b) 1972
  3. (c) 1984
  4. (d) 1998
Answer & solution

Answer: (b) 1972

The Department of Space (DOS) was established in India in 1972 by the Government of India to bring the space activities of the country under a coordinated structure. ISRO (Indian Space Research Organisation) functions under the DOS. The Prime Minister of India serves as the Minister of Space.
Why other options are incorrect:
- 1961: INCOSPAR (Indian National Committee for Space Research), the precursor to ISRO, was established in 1962; DOS came later in 1972.
- 1984: By 1984, the DOS had already been functioning for over a decade.
- 1998: This is well after the establishment of DOS.
SSC MTS 2025 – 12 February 2026 Shift 1 · Indian space missions

Q76. In the context of Chandrayaan -III mission, the ILSA payload was used to _____.

  1. (a) detect moonquakes
  2. (b) study Earth's spectral and polarimetric properties from lunar orbit
  3. (c) measure thermal conductivity from lunar surface
  4. (d) study the plasma density on lunar surface
Answer & solution

Answer: (a) detect moonquakes

Correct Answer: Option 1 – detect moonquakes
ILSA stands for Instrument for Lunar Seismic Activity. It was one of the payloads on the Vikram lander of Chandrayaan-3. ILSA was designed to detect seismic activity (moonquakes) on the lunar surface and study the structure of the Moon's crust. It successfully recorded the first-ever seismic event on the Moon by the Chandrayaan-3 mission.
Why other options are wrong:
Option 2: Studying Earth's spectral properties from lunar orbit was the purpose of a different payload (SHAPE — Spectro-polarimetry of HAbitable Planet Earth), not ILSA.
Option 3: Thermal conductivity was measured by ChaSTE (Chandra's Surface Thermophysical Experiment), not ILSA.
Option 4: Plasma density was studied by RAMBHA-LP (Radio Anatomy of Moon Bound Hypersensitive ionosphere and Atmosphere), not ILSA.
SSC MTS 2025 – 12 February 2026 Shift 1 · Space tourism and commercial spaceflight

Q77. "Vikram-S" India's first ever private launch vehicle has been developed by _____.

  1. (a) Skyroot Aerospace
  2. (b) Agnikul Cosmos
  3. (c) Bellatrix Aerospace
  4. (d) Pixxel
Answer & solution

Answer: (a) Skyroot Aerospace

Correct Answer: Option 1 – Skyroot Aerospace
Vikram-S is India's first privately developed rocket, built by Skyroot Aerospace, a Hyderabad-based space start-up. It was successfully launched on 18 November 2022 from the Satish Dhawan Space Centre, Sriharikota , under the mission name 'Prarambh'. This marked a historic milestone in India's private space sector.
Why other options are wrong:
Option 2 ( Agnikul Cosmos): Agnikul is another Indian space start-up but their rocket is called ' Agnibaan ', not Vikram-S.
Option 3 (Bellatrix Aerospace): Bellatrix focuses on satellite propulsion systems and is not associated with Vikram-S.
Option 4 ( Pixxel ): Pixxel is a satellite imaging company and is not a launch vehicle manufacturer.
SSC MTS 2025 – 12 February 2026 Shift 3 · Launch vehicles and satellites

Q78. The Navigation with Indian Constellation (NavIC) coverage area includes India and a region up to _____ km beyond the Indian boundary.

  1. (a) 1500
  2. (b) 4000
  3. (c) 6500
  4. (d) 7000
Answer & solution

Answer: (a) 1500

Correct Answer: Option 1 – 1500
NavIC (Navigation with Indian Constellation), developed by ISRO, is India's own regional satellite navigation system. Its coverage area includes the entire Indian territory and a region extending up to 1500 km beyond India's boundary. This gives NavIC coverage over much of South Asia and the Indian Ocean region.
Why other options are wrong:
Option 2 (4000 km): Incorrect figure for NavIC's coverage range beyond India.
Option 3 (6500 km): Incorrect; this would cover a much larger international area.
Option 4 (7000 km): Incorrect; the official coverage is 1500 km beyond the Indian boundary.
SSC MTS 2025 – 10 February 2026 Shift 1 · ISRO - history and centres

Q79. The U . R . Rao Satellite Centre is in _____.

  1. (a) Chennai
  2. (b) Bengaluru
  3. (c) Kochi
  4. (d) Lucknow
Answer & solution

Answer: (b) Bengaluru

Correct Answer: 2 – Bengaluru.
The U R Rao Satellite Centre (URSC), formerly known as the ISRO Satellite Centre (ISAC), is located in Bengaluru, Karnataka. It is ISRO's primary facility for design, development, fabrication and testing of satellites. It was renamed in 2017 in honour of Prof. U. R. Rao, former ISRO chairman.
Chennai (Option 1) hosts ISRO's ISTRAC (Telemetry, Tracking and Command Network).
Kochi (Option 3) is not an ISRO satellite centre location.
Lucknow (Option 4) is not an ISRO facility location.
SSC MTS 2025 – 10 February 2026 Shift 3 · Indian space missions

Q80. In the context of India, which of the following is associated with "Shiv Shakti Point"?

  1. (a) Moon
  2. (b) Mars
  3. (c) Venus
  4. (d) Jupiter
Answer & solution

Answer: (a) Moon

The correct answer is Moon (Option 1). 'Shiv Shakti Point' is the name given by Prime Minister Narendra Modi to the landing site of India's Chandrayaan-3 mission's Vikram lander on the Moon's south polar region. The landing took place on August 23, 2023, making India the first country to land near the lunar south pole. Options 2, 3, and 4 (Mars, Venus, Jupiter) are incorrect as India's missions to those planets have different names.
SSC MTS 2025 – 10 February 2026 Shift 3 · International space missions and agencies

Q81. Which space agency's Hubble Space Telescope captured a cosmic 'bullseye galaxy' with nine rings?

  1. (a) ISRO
  2. (b) NASA
  3. (c) CNES
  4. (d) JAXA
Answer & solution

Answer: (b) NASA

The correct answer is NASA (Option 2). The Hubble Space Telescope (HST) is operated by NASA (National Aeronautics and Space Administration) in collaboration with ESA. It captured the image of a rare 'bullseye galaxy' (AM 0644-741) featuring nine rings, caused by a collision between galaxies. Option 1 is incorrect as ISRO is India's space agency and does not operate Hubble. Option 3 (CNES) is France's space agency. Option 4 (JAXA) is Japan's space agency.
SSC MTS 2025 – 9 February 2026 Shift 1 · International space missions and agencies

Q82. The International Space Station is a large space station in low earth orbit at about _____ Km from the Earth surface.

  1. (a) 400
  2. (b) 1000
  3. (c) 5000
  4. (d) 22000
Answer & solution

Answer: (a) 400

Correct Answer: 1 (400)
The International Space Station (ISS) orbits the Earth in Low Earth Orbit (LEO) at an altitude of approximately 400 km (ranging from about 370 km to 460 km) above the Earth's surface. At this altitude, it completes one orbit every 90 minutes and travels at about 28,000 km/h.
Option 2 (1000 km) is incorrect - this would be above the ISS orbit.
Option 3 (5000 km) is incorrect - the candidate chose this wrong option.
Option 4 (22000 km) is incorrect - approximately 36,000 km is the altitude of geostationary satellites.
SSC MTS 2025 – 9 February 2026 Shift 3 · ISRO - history and centres

Q83. The North-Eastern Space Applications Centre is in which of the following state?

  1. (a) Meghalaya
  2. (b) Assam
  3. (c) Nagaland
  4. (d) Arunachal Pradesh
Answer & solution

Answer: (a) Meghalaya

Correct Answer: 1 – Meghalaya.
The North-Eastern Space Applications Centre (NESAC) is located at Umiam ( Barapani ), near Shillong in Meghalaya. It is a joint initiative of the Department of Space (ISRO) and the North Eastern Council (NEC). NESAC provides space technology support for the development of the North-Eastern region of India.
Assam (Option 2), Nagaland (Option 3), and Arunachal Pradesh (Option 4) do not host NESAC.
SSC MTS 2025 – 9 February 2026 Shift 3 · Science and technology missions and schemes

Q84. The National Green Hydrogen Mission in India aims to achieve a targeted production capacity of _____ million tonnes per annum green hydrogen by 2030.

  1. (a) 2
  2. (b) 3
  3. (c) 5
  4. (d) 7
Answer & solution

Answer: (c) 5

Correct Answer: 3 – 5 million tonnes per annum.
The National Green Hydrogen Mission was approved by the Government of India in January 2023. Its key target is to produce 5 Million Metric Tonnes (MMT) of green hydrogen per annum by 2030. The mission also aims to reduce carbon dioxide emissions by 50 million metric tonnes per annum.
Options 1 (2 MMTPA), 2 (3 MMTPA), and 4 (7 MMTPA) are incorrect figures.
SSC MTS 2025 – 6 February 2026 Shift 1 · International space missions and agencies

Q85. The International Space Station orbit the earth approximately _____ times a day.

  1. (a) 8
  2. (b) 16
  3. (c) 10
  4. (d) 18
Answer & solution

Answer: (b) 16

Correct Answer: 2 (16)
The International Space Station (ISS) orbits the Earth at an altitude of approximately 400 km, traveling at about 28,000 km/h. At this speed, it completes approximately 15.5 orbits per day, which is commonly rounded to 16 orbits per day.
Option 1 (8) is incorrect - this is much less than the actual number.
Option 3 (10) is incorrect.
Option 4 (18) is incorrect - the ISS completes roughly 15-16 orbits, not 18.
SSC MTS 2025 – 6 February 2026 Shift 2 · Indian space missions

Q86. In the context of Chandrayaan-III mission, the SHAPE payload was used to _____.

  1. (a) detect moonquakes
  2. (b) study Earth's spectral and polarimetric properties from lunar orbit
  3. (c) measure thermal conductivity from lunar surface
  4. (d) study the plasma density on lunar surface
Answer & solution

Answer: (b) study Earth's spectral and polarimetric properties from lunar orbit

Correct Answer: 2 (study Earth's spectral and polarimetric properties from lunar orbit)
SHAPE (Spectro-polarimetry of HAbitable Planet Earth) was a payload aboard the Chandrayaan-3 Propulsion Module. Its purpose was to study the spectral and polarimetric properties of Earth as seen from lunar orbit, helping scientists understand what signatures to look for when studying exoplanets that might be habitable.
Option 1 (detect moonquakes) is incorrect - that was the purpose of ILSA (Instrument for Lunar Seismic Activity) on the Vikram lander.
Option 3 (measure thermal conductivity) is incorrect - that was done by ChaSTE (Chandra's Surface Thermophysical Experiment).
Option 4 (study plasma density) is incorrect - that was done by RAMBHA (Radio Anatomy of Moon Bound Hypersensitive ionosphere and Atmosphere).
SSC MTS 2025 – 4 February 2026 Shift 3 · International space missions and agencies

Q87. The International Space Station was launched in _____.

  1. (a) 1965
  2. (b) 1972
  3. (c) 1998
  4. (d) 2004
Answer & solution

Answer: (c) 1998

Correct Answer: 1998
The International Space Station (ISS) was launched on November 20, 1998, with the Russian Zarya module being its first component. The project is a collaboration between NASA, Roscosmos, ESA, JAXA, and CSA.
Why other options are wrong:
1965 - Year of the first spacewalk by Alexei Leonov.
1972 - Apollo 17 moon mission year.
2004 - ISS was already operational; not its launch year.
SSC MTS 2025 – 4 February 2026 Shift 3 · International space missions and agencies

Q88. The International Space Station travels from west to east on an orbital inclination of _____ degrees.

  1. (a) 51.6
  2. (b) 184.3
  3. (c) 234.6
  4. (d) 312.5
Answer & solution

Answer: (a) 51.6

Correct Answer: 51.6
The ISS orbits Earth at an inclination of 51.6 degrees to the equator. This inclination was chosen to make the ISS accessible to both Russian launch sites (Baikonur, Kazakhstan) and American launch sites (Kennedy Space Center, Florida).
Why other options are wrong:
184.3, 234.6, 312.5 - These are not valid orbital inclination values. Orbital inclination ranges from 0 to 180 degrees only.
SSC MTS 2025 – 4 February 2026 Shift 3 · International space missions and agencies

Q89. The 'EnVision' mission of the European Space Agency is aimed at exploring which planet?

  1. (a) Mars
  2. (b) Venus
  3. (c) Jupiter
  4. (d) Mercury
Answer & solution

Answer: (b) Venus

Correct Answer: Venus
The EnVision mission is ESA's planned orbiter mission to Venus. It aims to study Venus's atmosphere, surface, and interior to understand why Venus and Earth evolved so differently despite being similar in size and composition.
Why other options are wrong:
Mars - Explored by ESA's Mars Express and ExoMars missions.
Jupiter - Explored by ESA's JUICE (Jupiter Icy Moons Explorer) mission.
Mercury - Explored by ESA's BepiColombo mission.
Delhi Police Head Constable (Ministerial) 2025-26 – 12 January 2026 Shift 3 · Science and technology missions and schemes

Q90. Which of the following statements about the Vaishvik Bhartiya Vaigyanik (VAIBHAV) Fellowship Programme is incorrect?

  1. (a) VAIBHAV aims to engage the Indian diaspora scientists and researchers globally to contribute to India's scientific and technological development.
  2. (b) The Fellowship provides financial support for Indian-origin scientists to relocate permanently to India within a maximum of five years.
  3. (c) VAIBHAV encourages collaborative research projects between Indian academic institutions and Indian-origin scientists abroad.
  4. (d) The programme is administered by the Ministry of Science and Technology, Government of India.
Answer & solution

Answer: (b) The Fellowship provides financial support for Indian-origin scientists to relocate permanently to India within a maximum of five years.

Option 2 is the incorrect statement. The VAIBHAV (Vaishvik Bhartiya Vaigyanik) Fellowship does NOT support permanent relocation to India. It is designed for short-term, part-time engagement — Indian-origin scientists working abroad can collaborate with Indian institutions for a period of up to one month per year (for a maximum of 3 years), without leaving their current positions overseas. The goal is collaborative research, not permanent immigration.
• Option 1 is correct: VAIBHAV indeed aims to leverage the global Indian scientific diaspora for India's technological development.
• Option 3 is correct: The scheme specifically promotes collaborative research between overseas Indian scientists and Indian academic/R&D institutions.
• Option 4 is correct: The programme is administered by the Ministry of Science and Technology, Department of Science and Technology (DST), Government of India.
Delhi Police Head Constable (Ministerial) 2025-26 – 10 January 2026 Shift 1 · Indian space missions

Q91. What is the main payload of Aditya-L1 to study the solar corona?

  1. (a) SUIT
  2. (b) XPoSat
  3. (c) VELC
  4. (d) RHESSI
Answer & solution

Answer: (c) VELC

The Visible Emission Line Coronagraph (VELC) is the primary and largest payload of India's Aditya-L1 solar mission (launched September 2023). It is specifically designed to continuously image the solar corona and study coronal mass ejections (CMEs) and solar dynamics.
(1) SUIT (Solar Ultraviolet Imaging Telescope) is another Aditya-L1 payload but studies the Sun in UV wavelengths, not primarily the corona.
(2) XPoSat is a separate ISRO mission for X-ray polarimetry and is not a payload on Aditya-L1.
(4) RHESSI (Reuven Ramaty High Energy Solar Spectroscopic Imager) is a NASA mission, not part of Aditya-L1.
Delhi Police Constable (Exe) 2025-26 – 6 January 2026 Shift 1 · Evacuation and humanitarian relief operations

Q92. What was the purpose of 'Operation Ganga', launched by the Indian government in 2022?

  1. (a) To clean the Ganga river
  2. (b) To evacuate Indian citizens stranded in Ukraine
  3. (c) To provide aid to Sri Lanka
  4. (d) To protect the Ganges river dolphin
Answer & solution

Answer: (b) To evacuate Indian citizens stranded in Ukraine

The correct answer is (b) To evacuate Indian citizens stranded in Ukraine.
Operation Ganga was a humanitarian evacuation mission launched by the Indian government in February-March 2022 to evacuate Indian nationals (primarily students) stranded in Ukraine following Russia's military invasion of Ukraine. Multiple special flights were operated from neighboring countries (Romania, Hungary, Poland, Slovakia) to evacuate thousands of Indians.
(a) To clean the Ganga river: Namami Gange Programme is the initiative for Ganga rejuvenation; not called Operation Ganga.
(c) To provide aid to Sri Lanka: Operation Karuna was the Indian mission providing humanitarian aid to Sri Lanka during its economic crisis (2022); not Operation Ganga.
(d) To protect the Ganges river dolphin: Conservation efforts are part of Project Dolphin (launched 2020); not Operation Ganga.
Delhi Police Constable (Exe) 2025-26 – 6 January 2026 Shift 2 · Science and technology missions and schemes

Q93. According to the 2025 update of the INSPIRE Faculty Fellowship, what is the consolidated monthly emolument awarded to each selected fellow for the full five-year tenure?

  1. (a) ₹1,00,000
  2. (b) ₹1,10,000
  3. (c) ₹1,25,000
  4. (d) ₹1,50,000
Answer & solution

Answer: (c) ₹1,25,000

The correct answer is (c) ₹1,25,000.
As per the 2025 update of the INSPIRE Faculty Fellowship (Innovation in Science Pursuit for Inspired Research) by the Department of Science and Technology (DST), the consolidated monthly emolument for each selected fellow is ₹1,25,000 for the full five-year tenure. INSPIRE Faculty Fellowship supports young researchers in developing independent research programs in India.
(a) ₹1,00,000: Not the updated 2025 consolidated monthly emolument for INSPIRE Faculty Fellowship.
(b) ₹1,10,000: Not the updated 2025 amount; the correct figure is ₹1,25,000.
(d) ₹1,50,000: Higher than the specified amount; not the 2025 consolidated monthly emolument.
Delhi Police Constable (Exe) 2025-26 – 5 January 2026 Shift 3 · Indian armed forces - structure and ranks

Q94. India's only tri-service command located in the Indian Ocean region is at which location, combining the Army, Navy, and Air Force under a unified command?

  1. (a) Lakshadweep
  2. (b) Car Nicobar
  3. (c) Port Blair
  4. (d) Kavaratti
Answer & solution

Answer: (c) Port Blair

The correct answer is (c) Port Blair.
India's only tri-service (joint) command is the Andaman and Nicobar Command (ANC), headquartered at Port Blair in the Andaman and Nicobar Islands. Established in 2001, it integrates the Indian Army, Indian Navy, Indian Air Force, and Indian Coast Guard under a single unified command. It is strategically located in the Indian Ocean region.
(a) Lakshadweep: A Union Territory in the Arabian Sea; has INS Dweeprakshak but no tri-service command.
(b) Car Nicobar: An island in the Andaman & Nicobar group; hosts an Air Force station but not the tri-service command HQ.
(d) Kavaratti: The capital of Lakshadweep; not the location of the tri-service command.
Delhi Police Constable (Exe) 2025-26 – 5 January 2026 Shift 3 · International space missions and agencies

Q95. Which was the first artificial satellite to orbit Earth, marking the beginning of the space age in 1957?

  1. (a) Sputnik 1
  2. (b) Explorer 1
  3. (c) Vanguard 1
  4. (d) Luna 1
Answer & solution

Answer: (a) Sputnik 1

The correct answer is (a) Sputnik 1.
Sputnik 1, launched by the Soviet Union on October 4, 1957, became the first artificial satellite to orbit Earth, marking the beginning of the Space Age. It completed one orbit every 96 minutes and transmitted radio signals for 21 days before its batteries died.
(b) Explorer 1: The first American satellite, launched on January 31, 1958 — over three months after Sputnik 1.
(c) Vanguard 1: Launched by the USA on March 17, 1958; the oldest satellite still in orbit, but not the first.
(d) Luna 1: Launched by the Soviet Union in January 1959; it was the first spacecraft to escape Earth's gravity and reach the vicinity of the Moon; not an Earth-orbiting satellite.
Delhi Police Constable (Exe) 2025-26 – 4 January 2026 Shift 2 · Launch vehicles and satellites

Q96. Which type of orbit does PSLV (Polar Satellite Launch Vehicle) primarily use?

  1. (a) Geostationary orbit
  2. (b) Polar orbit
  3. (c) Elliptical orbit
  4. (d) Equatorial orbit
Answer & solution

Answer: (b) Polar orbit

PSLV primarily uses polar orbits, which pass over the Earth's poles and allow satellites to cover the entire Earth's surface as it rotates.
(a) Incorrect: Geostationary orbit is typically used by GSLV for communication satellites, not PSLV.
(c) Incorrect: Elliptical orbit is not the primary orbit used by PSLV.
(d) Incorrect: Equatorial orbit is associated with geostationary satellites, not PSLV missions.
Delhi Police Constable (Exe) 2025-26 – 30 December 2025 Shift 2 · Evacuation and humanitarian relief operations

Q97. The Silkyara-Barkot tunnel, which was in the news due to a major rescue operation, is located in which state?

  1. (a) Himachal Pradesh
  2. (b) Uttarakhand
  3. (c) Arunachal Pradesh
  4. (d) Sikkim
Answer & solution

Answer: (b) Uttarakhand

The Silkyara-Barkot tunnel is located in Uttarkashi district of Uttarakhand. It gained national attention in November 2023 when 41 workers were trapped inside during construction and were rescued after 17 days in a dramatic multi-agency operation.
(a) Incorrect: Himachal Pradesh does not host the Silkyara-Barkot tunnel; this tunnel is part of the Char Dham highway project in Uttarakhand.
(c) Incorrect: Arunachal Pradesh is in northeast India and is not associated with the Silkyara-Barkot tunnel.
(d) Incorrect: Sikkim does not host this tunnel; the Silkyara-Barkot tunnel is specifically in Uttarkashi, Uttarakhand.
Delhi Police Constable (Exe) 2025-26 – 29 December 2025 Shift 1 · ISRO - history and centres

Q98. Which of the following best describes the shift in ISRO's manufacturing strategy per the 2023 policy?

  1. (a) ISRO will shut down its production facilities
  2. (b) ISRO will keep research and hand over "mature" systems to private/public companies
  3. (c) ISRO will produce everything and disallow private manufacturing
  4. (d) ISRO will focus only on launchers, not spacecraft
Answer & solution

Answer: (b) ISRO will keep research and hand over "mature" systems to private/public companies

As per ISRO's 2023 manufacturing policy, ISRO will continue to focus on research, development, and innovation, while handing over proven/mature space systems to private and public sector companies for commercial production. This enables industry to take over manufacturing, freeing ISRO for newer technologies.
(a) Incorrect: ISRO is not shutting down; it is expanding research focus.
(c) Incorrect: ISRO is actively encouraging private sector participation.
(d) Incorrect: ISRO develops a full range of space systems, including satellites and spacecraft.
Delhi Police Constable (Exe) 2025-26 – 29 December 2025 Shift 2 · Indian space missions

Q99. The Solar Low Energy X-ray Spectrometer ( SoLEXS ) onboard the Aditya-L1 mission operates in which energy range?

  1. (a) 0.1 – 1 keV
  2. (b) 2 – 22 keV
  3. (c) 50 – 100 keV
  4. (d) 100 – 1000 keV
Answer & solution

Answer: (b) 2 – 22 keV

The SoLEXS (Solar Low Energy X-ray Spectrometer) on Aditya-L1 is designed to monitor the Sun's soft X-ray emissions to study solar flares and their precursors. It operates in the soft X-ray range of approximately 2–22 keV as per the instrument specifications for solar activity monitoring.
(a) Incorrect: 0.1–1 keV is an extremely low energy range below SoLEXS's designed band.
(c) Incorrect: 50–100 keV is in the hard X-ray range, handled by HEL1OS on Aditya-L1.
(d) Incorrect: 100–1000 keV corresponds to gamma-ray energies, far beyond SoLEXS's range.
Delhi Police Constable (Exe) 2025-26 – 29 December 2025 Shift 3 · Indian space missions

Q100. Which payload is NOT included on Aditya-L1, although it is part of another ISRO mission for X-ray studies?

  1. (a) SUIT (Solar UV Imaging Telescope)
  2. (b) VELC (Visible Emission Line Coronagraph)
  3. (c) POLIX (X-ray polarimeter)
  4. (d) SoLEXS (Soft X-ray Spectrometer)
Answer & solution

Answer: (c) POLIX (X-ray polarimeter)

POLIX (X-ray Polarimeter) is NOT part of Aditya-L1. POLIX is the primary instrument on ISRO's XPoSat (X-ray Polarimeter Satellite), launched in December 2023, for studying X-ray polarimetry of cosmic sources. Aditya-L1's seven payloads include VELC, SUIT, SoLEXS, HEL1OS, ASPEX, PAPA, and MAG for solar studies from the L1 Lagrange point.
(a) Incorrect: SUIT (Solar UV Imaging Telescope) IS on Aditya-L1; it images the Sun in ultraviolet light.
(b) Incorrect: VELC (Visible Emission Line Coronagraph) IS on Aditya-L1; it studies the solar corona.
(d) Incorrect: SoLEXS (Soft X-ray Spectrometer) IS on Aditya-L1; it monitors solar X-ray emissions.
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