ISRO lifts heaviest satellite using its heaviest rocket


Sriharikota: The heaviest launch vehicle of the Indian Space Research Organisation (ISRO), called GSLV MkIII D-1, lifted today its heaviest satellite. The rocket took off at 5:28 PM from the second launch pad of the Satish Dhawan Space Centre situated in this barrier island off the Bay of Bengal coast located in Andhra Pradesh.

This was the first orbital mission of GSLV MkIII which was mainly intended to evaluate the vehicle performance including that of its fully indigenous cryogenic upper stage during the flight. Weighing 3,136 kg at lift-off, GSAT-19 is the heaviest satellite launched from the Indian soil.

GSLV-Mk III-D1 is the first developmental flight to a Geosynchronous Transfer Orbit (GTO). The vehicle is configured with a 5 m ogive payload fairing and slanted strap-on nose cone to provide aerodynamic robustness. The rocket is capable of launching 4-tonne class of satellites to a GTO. It is a 3-stage vehicle with 2 solid motor strap-ons (S200), a liquid propellant core stage (L110) and a cryogenic stage (C25).

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Technical specifications

Payload to GTO: 4,000 kg

GSLV Mk III will be capable of placing the 4-tonne class satellites of the GSAT series into Geosynchronous Transfer Orbits.




Payload to LEO: 8,000 kg

The powerful cryogenic stage of GSLV Mk III enables it to place heavy payloads into Low Earth Orbits of 600 km altitude.



Cryogenic Upper Stage: C25

The C25 is powered by CE-20, India’s largest cryogenic engine, designed and developed by the Liquid Propulsion Systems Centre.

Cryo Stage height : 13.5 m
Cryo Stage diameter : 4.0 m
Engine : CE-20
: 28 tonnes of LOX + LH2

Solid Rocket Boosters : S200

GSLV Mk III uses two S200 solid rocket boosters to provide the huge amount of thrust required for lift off. The S200 was developed at Vikram Sarabhai Space Centre.

Booster height : 25 m
Booster diameter : 3.2 m
: 205 tonne of HTPB (nominal)

Core Stage: L110 Liquid Stage

The L110 liquid stage is powered by two Vikas engines designed and developed at the Liquid Propulsion Systems Centre.

Stage height : 21 m
Stage diameter : 4 m
Engine : 2 x Vikas
: 110 tonne of UDMH + N2O4


After a 25.5 h smooth countdown, the mission began with the launch of the 640-tonne GSLV Mk-III at 5:28 pm IST from the second launch pad as scheduled with the ignition of its two S200 solid strap-on boosters.

Following this, the major phases of the flight occurred as scheduled. The upper stage of GSLV MkIII vehicle is a new cryogenic stage (C25) indigenously configured, designed and realised by ISRO. The cryogenic stage used liquid hydrogen and liquid oxygen as propellants with a total loading of 28 tons. The stage is powered by a 20-tonne thrust cryogenic engine (CE20) operating on ‘gas generator cycle’. The performance of the engine and stage during the mission was as predicted. About 16 min after the lift-off, GSAT-19 satellite was successfully placed in orbit.

Soon after its separation from GSLV, the Master Control Facility (MCF) at Hassan in Karnataka assumed control of the satellite. GSAT-19 is a high throughput communication satellite.

In the coming days, the GSAT-19 orbit will be raised from its present Geosynchronous Transfer Orbit (GTO) to the final circular Geostationary Orbit (GSO) by firing the satellite’s Liquid Apogee Motor (LAM) in stages.  During the final phase of this operation, the solar panels and antenna reflectors of the satellite will be deployed. The satellite will be commissioned into service after its positioning in the designated slot in the GSO following in-orbit testing of its payloads.

Why the success of this GSLV is a big deal for India

Thirty-five years ago, India first thought of building a cryogenic engine that would give a rocket a thrust of 10 tonne. In December 1982, a cryogenic study team was formed to meet that end. The technical intricacies of the project, however, inhibited the team’s progress. India then asked Russia to supply it with the engine.

Nine years later, ISRO and Glavkosmos of Russia signed a $120-million contract for 7 cryogenic rocket engines; the deal included a complete transfer of technology. No other country was willing to share this technology with India due to the apprehension we would use it for military purposes. Friendship with Russia could not rescue us, though.

In July 1993, the US forced Russia, which had recently lost the might of the Soviet Union, to deny India the engine with a purported reason that the transfer violated the Missile Technology Control Regime. Russia yielded and the GSLV programme was almost shelved.

The indigenous efforts that were put at bay earlier then resumed, with ISRO expediting its research at the Liquid Propulsion Systems Centre at Mahendragiri in Tamil Nadu. By the turn of the decade, Russia agreed to supply to India the 7 promised cryogenic engines. Thereafter, the rocket went through a phase of hits and misses until it saw the success today.
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