Geosynchronous Satellite Launch Vehicle Mark III

The Geosynchronous Satellite Launch Vehicle Mark III (GSLV Mk III) — officially renamed LVM3 — is India’s most powerful operational launch vehicle built to carry heavy satellites and support future human spaceflight missions.
ISRO
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It represents a significant leap over earlier Indian launchers like the PSLV (Polar Satellite Launch Vehicle) and GSLV Mk II, offering much greater payload capacity and flexibility.
ISRO

📏 Key Physical & Performance Specifications
Parameter Value / Detail
Height ~43.5 m (about a 14-storey building)
ISRO

Diameter 4 m core; 5 m payload fairing
ISRO

Liftoff Mass ~640 tonnes
ISRO

Stages 3 (Solid strap-ons + Liquid core + Cryogenic upper)
ISRO

Payload to GTO ~4 000 kg (design aim)
ISRO

Payload to LEO ~8 000–10 000 kg (to lower orbit)
ISRO
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👉 The LEO capacity is much higher than GTO because achieving geostationary transfer requires more energy.
ISRO

🧱 Three-Stage Configuration
🔹 Stage 1 — S200 Solid Rocket Boosters

Two large solid boosters strapped to the core.

Each carries ~205 t of solid propellant (HTPB).
ISRO

Provides the main thrust at liftoff.

Burn ~130–140 s before separation.
NSIL India

🔹 Stage 2 — L110 Liquid Core Stage

Core liquid stage with two Vikas engines burning UDMH + N₂O₄ propellants.
Testbook

Ignites after liftoff while strap-ons are still burning to augment thrust.
NSIL India

🔹 Stage 3 — C25 Cryogenic Upper Stage

Uses the CE-20 indigenous cryogenic engine burning liquid hydrogen (LH₂) and liquid oxygen (LOX).
ISRO

Provides efficient high-altitude propulsion.

The CE-20 is India’s largest cryogenic engine and a key technological milestone for ISRO.