Current Affairs · · GS3 · Science & Technology

ISRO confirms NVS-03 in orbit, begins raising it to NavIC slot

ISRO has confirmed that GSLV-F18 placed the NVS-03 navigation satellite in a geosynchronous transfer orbit after its 30 October launch. The first orbit-raising manoeuvre was completed on 31 October. Further firings will take it to its slot at 111.75° East, after which it can strengthen NavIC, India's own navigation system.

Event date:

REq1
  1. Note1 / 7

    WHY IN NEWS?

    • ISRO launched GSLV-F18 at 23:51 IST on 30 October 2026 from the Satish Dhawan Space Centre, Sriharikota.
    • It placed the NVS-03 navigation satellite precisely in a geosynchronous transfer orbit (GTO).
    • The first orbit-raising manoeuvre was completed at 16:48 IST on 31 October 2026.
    • Further manoeuvres will place it at its designated slot at 111.75° East.
    • It is the 20th flight of the GSLV.
    • NVS-03 is the third of five next-generation satellites meant to strengthen NavIC (Navigation with Indian Constellation).
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    HOW A SATELLITE REACHES ITS FINAL ORBIT

    1. What is a geosynchronous transfer orbit?

    It is an elongated, temporary orbit. Its closest point to Earth, the perigee, is low. Its farthest point, the apogee, is about 35,786 km above Earth's surface.

    1. How does the satellite climb from there?

    Near the apogee, it fires its own engine. This raises the perigee and makes the orbit circular. Further firings adjust its tilt and position.

    1. What engine does NVS-03 use?

    A Liquid Apogee Motor (LAM), a type of chemical rocket engine. Engines used for such firings are commonly called apogee motors.

    1. Where will NVS-03 settle?

    At 111.75° East in geosynchronous orbit, where it will join the NavIC constellation after in-orbit tests.

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    ABOUT THE GSLV

    The table summarises the launch vehicle.

    FeatureDetail
    TypeThree-stage launch vehicle developed by ISRO
    Orbits servedGeosynchronous transfer orbit and low Earth orbit
    Height and lift-off mass (F18)About 50 metres; about 420 tonnes
    Payload fairing (F18)3.4-metre-diameter metallic fairing
    Payload carried (F18)NVS-03, about 2,250 kg
    Strap-on boostersLiquid-fuelled L-40 boosters
    Booster propellantsNitrogen tetroxide with UH25 (75% UDMH and 25% hydrazine hydrate), a hypergolic mix
    Upper stageIndigenous cryogenic stage
    1. What is a cryogenic upper stage?

    It is a final rocket stage that uses propellants stored at extremely low temperatures. ISRO's version burns liquid hydrogen as fuel and liquid oxygen as oxidiser.

    1. Why does it matter?

    It gives high efficiency for placing satellites in their intended orbits. It replaced the Russian-supplied stage used on earlier GSLV flights, strengthening self-reliance in advanced launch technology.

    1. What is a hypergolic propellant?

    A fuel and oxidiser pair that ignites on contact, without a separate ignition system.

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    WHAT NVS-03 CARRIES

    • Signals in three bands: Navigation payloads in the L1, L5 and S frequency bands.
    • L1 added: The L1 signal, alongside L5 and S, improves NavIC's capabilities and compatibility with common receivers.
    • Multiple bands: Using several bands lets compatible receivers access signals at different frequencies. It also allows receivers to be designed for different uses and conditions.
    • Clocks: An indigenously developed atomic clock alongside procured atomic clocks.
    • Why clocks matter: They provide very precise time references for generating signals. Accurate timing is needed to measure how long signals take to travel and to calculate a user's position.
    • Coverage: India's landmass and a region about 1,500 km beyond its boundary.
    • Mass: About 2,250 kg.
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    UNDERSTANDING SATELLITE NAVIGATION AND NAVIC

    1. What is a satellite navigation system?

    A network of satellites that provides positioning, navigation and timing information. Satellites continuously send signals with their location and precise time. Receivers in phones, vehicles and devices use signals from several satellites to work out location, speed and direction. Examples include the US Global Positioning System (GPS) and India's NavIC.

    1. What are navigation signals and frequency bands?

    Navigation signals are radio signals carrying precise timing and satellite-position data. Frequency bands are set ranges of the radio spectrum used to send them.

    1. What is NavIC?

    India's regional satellite navigation system, developed by ISRO and earlier called the Indian Regional Navigation Satellite System (IRNSS). It provides positioning, navigation and timing (PNT) services.

    1. How is it designed?

    Seven satellites — three in geostationary orbit and four in inclined geosynchronous orbit — supported by ground stations working round the clock. The NVS series augments this constellation and ensures continuity. The NVS series adds L1 to the earlier L5 and S signals.

    1. What services does it offer?
    • Standard Positioning Service (SPS): Open to civilians. It is interoperable with GPS (US), GLONASS (Russia), Galileo (EU) and BeiDou (China).
      • Restricted Service (RS): An encrypted service only for authorised strategic users.
    1. Where is it used?

    Transport, maritime operations, aviation, disaster management, precision agriculture and strategic services.

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    THE NVS SERIES

    The table compares the five next-generation satellites.

    SatelliteLaunchVehicleBandsMassKey points
    NVS-0129 May 2023GSLV-F12 (15th GSLV flight)L1, L5, SAbout 2,232 kg12-year life; indigenous rubidium atomic clock built by the Space Applications Centre, Ahmedabad
    NVS-0229 January 2025GSLV-F15L1, L5, S, plus C-band ranging2,250 kgMix of indigenous and procured clocks; oxidiser valves did not open, so orbit-raising failed and it did not reach its slot
    NVS-0330 October 2026GSLV-F18 (20th GSLV flight)L1, L5, SAbout 2,250 kgIndigenous and procured clocks; in GTO, orbit-raising under way
    NVS-04Planned–L1, L5, S–In the pipeline
    NVS-05Planned–L1, L5, S–In the pipeline

    NVS-01, NVS-02 and NVS-03 have been launched; NVS-04 and NVS-05 are being prepared to improve coverage, reliability and availability.

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    WHY IT MATTERS AND WHAT COMES NEXT

    • Strategic autonomy: Strengthens India's independent PNT capability, reducing reliance on foreign systems.
    • Self-reliance: Indian-made clocks and the cryogenic stage cut dependence on imported technology.
    • Reliability lesson: The NVS-02 failure makes careful orbit-raising critical for NVS-03.
    • Next steps: More orbit-raising firings, in-orbit tests of payloads and clocks, then commissioning.
    • Completing the series: Launching NVS-04 and NVS-05 will secure NavIC's continuity.

Sources

Syllabus

PaperSubjectSub-topic
GS3Science & TechnologySpace technology, indigenisation of technology, security
PrelimsScience & TechnologyGSLV, cryogenic stage, GTO, liquid apogee motor, NavIC, NVS series, frequency bands

Topics

Information and Communication TechnologyPhysicsSpace Technology

Related previous-year questions

Asked in earlier UPSC Prelims papers on this topic. Answer, then check.

  1. UPSC Prelims 2018 · Science and Technology · Space Technology

    With reference to India's satellite launch vehicles, consider the following statements: 1. PSLVs launch the satellites useful for Earth resources monitoring whereas GSLVs are designed mainly to launch communication satellites. 2. Satellites launched by PSLV appear to remain permanently fixed in the same position in the sky, as viewed from a particular location on Earth. 3. GSLV Mk III is a four-staged launch vehicle with the first and third stages using solid rocket motors, and the second and fourth stages using liquid rocket engines. Which of the statements given above is/are correct?

    1. 1 only
    2. 2 and 3
    3. 1 and 2
    4. 3 only
    Show answer

    Answer: A. Only statement 1 is correct, so the answer is (a) 1 only. Statement 1 is CORRECT. The PSLV is designed mainly to deliver earth observation or remote sensing satellites of up to about 1750 kg to sun-synchronous circular polar orbits at 600 to 900 km altitude, while the GSLV is designed mainly to deliver communication satellites to the highly elliptical Geosynchronous Transfer Orbit. Statement 2 is INCORRECT. Appearing permanently fixed in the sky describes a geostationary satellite. PSLV payloads go chiefly to polar sun-synchronous and lower earth orbits, so they do not appear fixed. Statement 3 is INCORRECT. GSLV Mk III is a three-stage heavy lift vehicle with two solid strap-ons, a core liquid booster and a cryogenic upper stage, not a four-staged vehicle in the configuration described. SOURCE: The Hindu explainer on the difference between GSLV and PSLV; ISRO launch vehicle pages. HOW TO CRACK IT: The reasoning chain runs from orbit to function. A satellite appears fixed only if it orbits at the same rate the Earth rotates, which requires geosynchronous altitude, and that is the GSLV's job. Fixing the vehicle to the orbit, and the orbit to the mission, resolves statements 1 and 2 together and leaves only the stage count to check.

    Difficulty: medium · statement

    Open this question on its own page, with the full explanation →

  2. UPSC Prelims 2026 · Science and Technology · Space Technology

    Consider the following statements with regard to involvement of private entities in India's space programme: 1. Indian National Space Promotion and Authorisation Centre (IN-SPACe) is an autonomous agency formed to facilitate participation of private entities. 2. Agnikul Cosmos launched the world's first flight using 3D-printed rocket engine. 3. Skyroot Aerospace has developed liquid fuel for GSLV. Which of the statements given above is/are correct?

    1. 1 only
    2. 2 and 3 only
    3. 1 and 2 only
    4. 1, 2 and 3
    Show answer

    Answer: C. IN-SPACe (Indian National Space Promotion and Authorisation Centre) was established in 2020 as an autonomous body under the Department of Space to promote, support, and authorize private sector participation in India's space ecosystem. Statement 1 is correct: The Indian National Space Promotion and Authorisation Centre (IN-SPACe) is an autonomous agency formed to facilitate participation of private entities. It was established in 2020 as a single-window autonomous agency to encourage, support, and authorize private sector participation in India's space activities. Statement 2 is correct: Agnikul Cosmos launched the world's first flight using a 3D-printed rocket engine. Agnikul Cosmos achieved this milestone through its Agnibaan SOrTeD mission, which used a single-piece 3D-printed semi-cryogenic engine. Statement 3 is incorrect: Skyroot Aerospace developed the Vikram-S suborbital rocket using solid propulsion technology. It has not developed liquid fuel systems for GSLV, whose cryogenic engines were developed by ISRO. Statements 1 and 2 are correct, so the answer is Option (c).

    Difficulty: hard · statement

    Open this question on its own page, with the full explanation →

  3. UPSC Prelims 2018 · Science and Technology · Space Technology

    With reference to the Indian Regional Navigation Satellite System (IRNSS), consider the following statements: 1. IRNSS has three satellites in geostationary and four satellites in geosynchronous orbits. 2. IRNSS covers entire India and about 5500 sq. km beyond its borders. 3. India will have its own satellite navigation system with full global coverage by the middle of 2019. Which of the statements given above is/are correct?

    1. 1 only
    2. 1 and 2 only
    3. 2 and 3 only
    4. None
    Show answer

    Answer: A. Only statement 1 is correct, so the answer is (a) 1 only. Statement 1 is CORRECT. The IRNSS space segment is a constellation of seven satellites, called NavIC. Three sit in geostationary orbital slots and the remaining four in geosynchronous orbits with the required inclination and equatorial crossings in two different planes. Statement 2 is INCORRECT. IRNSS is designed to serve users in India and the region extending up to 1500 km from its boundary, which is its primary service area, with an extended service area beyond that. The figure of 5500 square kilometres both misstates the distance and uses the wrong unit for it. Statement 3 is INCORRECT. IRNSS is a regional system, and India will not have a satellite navigation system with full global coverage by the middle of 2019. SOURCE: ISRO IRNSS programme page, and The Hindu report on IRNSS-1I completing the navigation fleet. HOW TO CRACK IT: Read the unit, not just the number. Statement 2 offers an area in square kilometres where coverage beyond a border must be a distance, and 5500 square kilometres would be a trivially small patch. Unit mismatch is a quiet but reliable tell. The name itself, Indian Regional Navigation Satellite System, disposes of statement 3.

    Difficulty: medium · statement

    Open this question on its own page, with the full explanation →

Practice questions

  1. The final stage of India's GSLV uses:

    1. Solid propellant
    2. An indigenous cryogenic engine using liquid hydrogen and liquid oxygen
    3. Semi-cryogenic kerosene
    4. Electric propulsion
    Show answer

    Answer: B. It replaced a Russian-supplied stage used on earlier flights.

    Difficulty: easy · statement

  2. GSLV's L-40 strap-on boosters use which propellant combination?

    1. Liquid hydrogen and liquid oxygen
    2. Nitrogen tetroxide and UH25
    3. Kerosene and liquid oxygen
    4. HTPB solid fuel
    Show answer

    Answer: B. UH25 is 75% UDMH and 25% hydrazine hydrate; the pair is hypergolic.

    Difficulty: medium · statement

  3. Orbit-raising of NVS-03 from its transfer orbit is being done using its:

    1. Cryogenic upper stage
    2. Liquid apogee motor
    3. Strap-on boosters
    4. Ion thruster
    Show answer

    Answer: B. It fires near apogee to circularise the orbit.

    Difficulty: medium · statement

Mains practice

Answer-writing practice on this article. Attempt it first, then open the hints.

  1. GS3 · 250 words

    Discuss the significance of indigenous cryogenic engines and atomic clocks for India's space programme and strategic autonomy. What lessons does the NVS series offer?

    Show hints
    1. GSLV cryogenic stage, technology self-reliance
    2. NavIC design and services, L1 band
    3. NVS-02 failure, orbit-raising
    4. completing the constellation.