025. National | S & T
ISRO’s 100th Launch: GSLV-F15 Carries NVS-02 Satellite, Marking a Historic Milestone
Introduction
On January 29, 2025, the Indian Space Research Organisation (ISRO) achieved a major milestone with the successful completion of its 100th launch from the Satish Dhawan Space Centre in Sriharikota. This historic mission involved the GSLV-F15 launch vehicle, which carried the NVS-02 satellite into orbit — further strengthening India’s capabilities in space technology and navigation systems.
🚀 Overview of the Launch
- The GSLV-F15 lifted off smoothly and placed the NVS-02 satellite into its intended geosynchronous orbit.
- NVS-02 is the second satellite in the Navigation with Indian Constellation (NavIC) series.
- NavIC is India’s homegrown satellite navigation system, designed to provide accurate position and timing data over India and neighboring regions.
🌐 The mission highlights India’s ongoing commitment to building independent and resilient space infrastructure.
🛰️ Technical Specifications of NVS-02
| Parameter | Details |
|---|---|
| Mass | 2,250 kg |
| Bus Platform | I-2K |
| Navigation Bands | L1, L5, and S bands |
| Other Payloads | C-band ranging payload |
| Timing Mechanism | Combination of indigenous and imported atomic clocks for high-precision timekeeping |
⏱️ Accurate timing is crucial for navigation, communication systems, and synchronised data services.
🔧 Significance of GSLV-F15
- GSLV-F15 marks the 17th flight in the GSLV (Geosynchronous Satellite Launch Vehicle) series.
- It is the 11th flight using an indigenous cryogenic upper stage — a key achievement in launching heavier payloads.
- Cryogenic technology allows India to send satellites into higher orbits, reducing reliance on foreign launch systems.
🛰️ This reinforces India’s self-reliance in space missions and boosts its commercial launch potential.
📜 ISRO’s Launch Legacy: A Brief Historical Context
- ISRO’s first satellite launch took place on August 10, 1979, using the SLV-3 (Satellite Launch Vehicle-3 E10).
- Since then, ISRO has developed six generations of launch vehicles:
- SLV, ASLV, PSLV, GSLV, GSLV Mk III, and the new SSLV
- Each generation reflects India’s evolving space ambitions — from launching small satellites to undertaking interplanetary missions like Chandrayaan and Mangalyaan.
💡 The 100th launch is not just a number — it’s a symbol of scientific perseverance, technological growth, and national pride.
Conclusion
ISRO’s 100th launch with GSLV-F15 and NVS-02 stands as a shining example of India’s progress in space exploration. It marks a new chapter in the nation’s journey toward autonomous navigation, advanced payload deployment, and global space collaboration. With each mission, ISRO continues to strengthen India’s position as a leader in affordable and reliable space technology.
ISRO’s Launch Vehicle Overview:
- Satellite Launch Vehicle (SLV): Initiated India’s foray into space with four launches between 1979 and 1983.
- Augmented Satellite Launch Vehicle (ASLV): Served as a bridge between SLV and PSLV with four launches from 1987 to 1994.
- Polar Satellite Launch Vehicle (PSLV): ISRO’s workhorse with numerous successful missions since its first launch in 1993.
- Geosynchronous Satellite Launch Vehicle (GSLV): Designed for heavier payloads to geostationary orbits, operational since 2001.
- GSLV Mk III (LVM3): ISRO’s heavy-lift launcher, instrumental in missions like Chandrayaan-2 and Gaganyaan.
- Small Satellite Launch Vehicle (SSLV): Developed for on-demand small satellite launches, with initial flights in the early 2020s.
Notable Missions:
- Chandrayaan-1 (2008): India’s first lunar probe, which made significant discoveries about the Moon’s surface.
- Mars Orbiter Mission (Mangalyaan) (2013): India became the first Asian nation to reach Martian orbit and the first globally to do so on its maiden attempt.Wikipedia
- Chandrayaan-2 (2019): Featured an orbiter, lander, and rover; the orbiter continues to study the Moon from orbit.
- Aditya-L1 (2023): India’s first solar observatory mission to study the Sun’s corona and solar emissions.
You’re absolutely right, dear ‘g’! Thank you for pointing that out. Let me now give you a clean and complete add-on overview of ISRO’s cryogenic engine development journey, and how it fits into the evolution of its launch vehicles, especially the GSLV series — in your preferred calm and structured tone. 🌌🚀
🧊 ISRO and Cryogenic Engines: A Vital Chapter in India’s Space Journey
❓ What is a Cryogenic Engine?
A cryogenic engine is a type of rocket engine that uses liquid oxygen (LOX) and liquid hydrogen (LH2) as propellants — both stored at extremely low temperatures.
- 🔥 It produces high thrust with high efficiency
- 🛰️ Crucial for lifting heavier payloads into geosynchronous orbits
- ❄️ Requires advanced technology to handle super-cooled fuels
🧪 Why Cryogenic Engines Are Important for ISRO
- India initially relied on foreign cryogenic stages (notably from Russia).
- After technology denial from international partners, ISRO developed its own indigenous cryogenic upper stage (CE-7.5).
- This became a major self-reliance milestone in India’s space program.
🚀 Cryogenic Stages in ISRO’s Launch Vehicles
🔹 GSLV Mk I & Mk II
- Use a cryogenic upper stage (CUS) developed by ISRO
- First successful use: GSLV-D5 (January 2014)
- Payload capacity to GTO: ~2,500 kg
🔹 GSLV Mk III / LVM3
- Uses C25 cryogenic upper stage with CE-20 engine
- First successful flight: GSAT-19 mission (June 2017)
- Can lift 4,000 kg to GTO and 10,000 kg to LEO
- Used in Chandrayaan-2, Gaganyaan test flights, and future crewed missions
🌍 With the CE-20 engine, ISRO entered the heavy-lift launch category and proved capable of independent deep space missions.
📈 Cryogenic Milestones
| Year | Milestone | Launch Vehicle |
|---|---|---|
| 2001 | First GSLV flight (with Russian cryo stage) | GSLV-D1 |
| 2010 | First flight attempt with Indian cryo stage (partial failure) | GSLV-D3 |
| 2014 | First successful flight with Indian cryogenic engine | GSLV-D5 |
| 2017 | First flight of GSLV Mk III with C25 stage | GSLV Mk III / LVM3 |
✅ Significance
- Proved India’s engineering strength
- Enabled cost-effective satellite launches
- Opened doors to commercial launches of heavier foreign satellites
- Critical for human spaceflight (Gaganyaan) and future planetary missions
🏁 Conclusion
The development of cryogenic engines is a cornerstone achievement for ISRO. It transformed India from a dependent space player to an independent global launcher, ready to venture deeper into space with confidence.
