ISRO’s 100th Launch: GSLV-F15 Successfully Places NVS-02 in Orbit

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ISRO achieved its 100th rocket launch with the first launch of 2025, as the GSLV-F15 successfully placed the NVS-02 navigation satellite into orbit.

The GSLV-F15 is the 17th flight of India’s Geosynchronous Satellite Launch Vehicle (GSLV) and 11th flight with Indigenous Cryo stage. It is the 8th operational flight of GSLV with an indigenous Cryogenic stage.

NVS-02 is one of the five replacement satellites for the Indian Regional Navigation Satellite System, also referred to as NavIC (Navigation with Indian Constellation).
- It is the second satellite in the NVS series, part of the NavIC system.
- NVS-01, launched in May 2023, was the first second-gen NavIC satellite and carried India’s first indigenous atomic clock.

Heavier and longer mission life than previous satellites.
Indigenously developed atomic clock for improved accuracy.
Enabled with L1 frequency, widely used in the US GPS system, allowing better compatibility with personal trackers and other devices.
NVS-02 enhances the reliability and accessibility of India’s navigation system for both civilian and strategic applications.

NavIC is a seven-satellite regional positioning system that can provide location data on the Indian mainland and up to 1,500 kilometres around.

More accurate in India than GPS due to satellites positioned directly overhead.
Better signal availability in difficult terrains like valleys and forests, unlike GPS signals, which reach India at an angle.

NavIC is the only regional system in the world.
Japan’s QZSS augments GPS signals but is not independent.
Four global systems exist:
- GPS (USA)
- GLONASS (Russia)
- Galileo (Europe)
- Beidou (China)

ISRO traces its origins to the Indian National Committee for Space Research (1962) under the Department of Atomic Energy.
It was formally established in 1969, the same year the U.S. sent astronauts to the Moon. A dedicated Department of Space was created in 1972.

ISRO has developed six generations of launch vehicles, with four currently in operation:
- PSLV (Polar Satellite Launch Vehicle) – Workhorse rocket with 62 flights, capable of carrying nearly 2,000 kg to Low Earth Orbit (LEO). Only two launches have failed.
- GSLV (Geosynchronous Satellite Launch Vehicle) – Initially used Russian cryogenic engines, later replaced by India’s indigenously developed cryogenic stage. The GSLV-F15, used for the 100th launch, is part of this series.
- GSLV MkIII (LVM3) – India’s heaviest rocket, carrying up to 8,500 kg to LEO. Used for Chandrayaan-2, Chandrayaan-3, and will be adapted for the Gaganyaan human spaceflight mission.
- SSLV (Small Satellite Launch Vehicle) – Designed for commercial small satellite launches, with three developmental flights so far.

100 launches have placed 548 satellites (120 tonnes) into orbit, including 433 foreign satellites (23 tonnes).
ISRO has launched various communication, earth observation, navigation, and experimental satellites.
Scientific Missions include AstroSat, Mars Orbiter Mission (Mangalyaan), Chandrayaan 1, 2, and 3, XpoSat, and solar mission Aditya-L1.

To support these missions, ISRO is developing the Next Generation Launch Vehicle (NGLV):
- Capable of carrying 30,000 kg to Low Earth Orbit (LEO)
- Stands 91 meters tall, more than double the 43 meters of LVM3
- Features a reusable first stage, designed for 15–20 reuses, making launches more cost-effective

Approved by the Indian Cabinet at an estimated cost of ₹3,984.86 crores over four years
Designed to support NGLV and human spaceflight missions
Will enhance LVM3 launch capacity, boosting ISRO’s capability for heavy commercial missions