Space Launch Report:  GSLV
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Vehicle Configurations

Vehicle Components

GSLV Flight Record

India's Space Research Organization's (ISRO) 401 metric ton, 49 meter-tall, three-stage Geosynchronous Satellite Launch Vehicle (GSLV), designed to loft 2 ton satellites to geosynchronous transfer orbit (GTO), is a conglomerate of Indian, European, and Russian components. ISRO developed the rocket during the 1990s to create an indigenous communication satellite launch capability for India.

ISRO adapted stages from India'a Polar Satellite Launch Vehicle (PSLV) for GSLV. The first stage solid propellant motor and the liquid propellant second stage of PSLV, itself powered by engines used by Europe's Ariane 1, serve as the core first stage motor and the second stage of GSLV. The PSLV second stage was also used as the basis for the GSLV first stage liquid strap-on stages.

The first stage uses a 20.3 x 2.8 meter (m), 480 ton thrust solid motor, augmented by four 19.7 x 2.1 m L40 liquid strap-on motors. The non-separating L40s are powered by 70 ton thrust Viking 2 engines that burn UDMH/N2O4 for 160 seconds, 60 seconds longer than the core.

GSLV's 11.6 x 2.8 m GS-2 second stage starts its Viking 4 70 ton thrust engine just before first stage cutoff, to ensure propellant settling, and burns for 160 seconds. The Glavkosmos 12KRB Cryogenic Stage (CS) then ignites its 73.5 kN KVD-1 LH2/LOX engine for a planned 710 second burn. CS is the first Russian-built liquid-hydrogen upper stage to fly, but ISRO plans to replace it with its own LH2 third stage in a few years.

The vehicle is controlled by a strap-down inertial navigation/guidance system housed in a vehicle equipment bay that is mounted on a truss structure atop the third stage. A 7.8 meter tall, 3.4 meter diameter payload fairing protects the payload during ascent until it is jettisonned at an altitude of about 110 km during the second stage burn.

ISRO launched its first GSLV from Satish Dhawan Space Centre, SHAR, Sriharikota on April 18, 2001. An early third stage cutoff denied the 49-meter tall rocket's total success in the inaugural D-1 mission. G-Sat 1, a 1,540 kg test payload, fell about 4,000 km short of its planned 36,000 km geosynchronous transfer orbit (GTO) apogee. G-Sat was unable to make up the difference with its apogee motor and it ended up stranded in a 23-hour drift orbit. GSLV flew successfully in 2003 and 2004.

During a typical flight, the four liquid propellant (L-40) strap-on stages are ignited first. The solid propellant core stage, S125, is ignited 4.6 seconds later and liftoff occurs. The core stage burns for 100 seconds and the four L-40 strap-on stages continue to burn for an additional 60 seconds. Staging occurs at an altitude of about 73 km.

The GS2 liquid propellant second stage ignites 1.6 seconds before the separation of first stage, using a "fire in the hole" start sequence. The second stage burns for about 150 seconds. The payload fairing separates at about the 260 second point. Second stage separation occurs about 314 seconds after lift-off at an altitude of about 127 km.

The cryogenic third performs a single 710 second burn, boosting the payload to a velocity of 10.2 km per second. at an altitude of 195 km. This injects the payload into an elliptical transfer orbit (GTO) with a perigee of 180 km and an apogee of 35,975 km.

The original PSLV/GSLV launch complex was replaced in 2005 with a new, mobile launch facility. Whereas the original pad featured fixed launch stand and a 75 meter tall mobile service tower, the new pad uses rail-mobile launch stands that allow vehicles to be stacked in a vertical integration building located some distance from the launch pad itself.


GSLV serial F-02, the fourth GSLV to fly, failed during its July 10, 2006 attempt to launch Insat 4C from Satish Dhawan Space Center on Sriharikota island on India's east coast.

The failure began to make itself apparent almost immediately after liftoff when one of four liquid-fueled strap-on boosters failed. This created asymmetrical thrust that caused the vehicle to veer from its planned flight path.   The 49-metre-tall, 414 tonne, three-stage launcher broke up at relatively low altitude and fell into the Bay of Bengal within sight of the launch pad.

On July 31, 2006 ISRO Chairman G Madhavan Nair said that preliminary results of the investigation pointed toward a malfunction of the thrust controller in the strap-on booster engine.  Each booster is powered by a single 70-tonne thrust Vikas engine fed by 42 tonnes of hypergolic liquid propellant. Vikas are derived from Viking 2 engines originally used by Europe's Ariane 1 launcher. 

gslvf06b.jpg (2415 bytes)India's GSLV Suffers Second Failure of 2010

India Space Research Organization's GSLV-F06, a Mark 1 variant, suffered a control failure 47 seconds after liftoff from Sriharikota's Second Launch Pad on December 25, 2010.  The three stage launch vehicle turned sideways at an altitude of 9-10 km and began to disintegrate, a process completed by the transmission of a range destruct command 63 seconds after liftoff.  ISRO officials said that steering control commands had stopped reaching actuators on one or more of the four liquid strap on boosters.  The precise cause of the failure is under investigation.

GSLV-F06 carried 2.31 tonne GSAT-5P, a communications satellite bound for geosynchronous transfer orbit.  In order to lift GSAT-5P, GSLV-F06 was fitted with an enlarged 8.6 x 4 meter composite payload fairing and a stretched Russian powered third stage loaded with 15.2 tonnes of liquid hydrogen and liquid oxygen propellant.

It was the second failure of a GSLV in two 2010 attempts.  GSLV-D3, a Mark 2 variant with India's first cryogenic upper stage, failed on April 15, 2010 when the third stage engine failed at startup.  Only two of the seven GSLV launches performed since the rocket premiered in 2001 have flown as planned.

gslvd5.jpg (17894 bytes)GSLV with India's Cryogenic Stage Succeeds


India’s Geosynchronous Satellite Launch Vehicle (GSLV) successfully boosted the GSAT 14 communications satellite into geosynchronous transfer orbit on January 5, 2013.  It was the first success for the launch vehicle since 2004, and the first success for India's indigenously-developed, liquid hydrogen fueled Cryogenic Upper Stage (CUS). 

The 415 tonne, 49 meter tall three-stage GSLV Mk 2 rocket, fitted with a 3.4 meter diameter payload fairing, lifted off at 10:48 UTC from the Second Launch Pad at the Satish Dhawan Space Center at Sriharikota to begin the GSLV-D5 development mission.  It rose on 690.7 tonnes (1.52 million lbf) of liftoff thrust produced by a solid core motor augmented by four L40 liquid non-separating strap-on motors, each powered by a Vikas 2 engine that burned UDMH/N2O4 until cutoff 149 seconds after liftoff, about 60 seconds after the core burned out.  The liquid second stage, powered by a single Vikas 4 UDMH/N2O4 engine, performed a 140.5 second burn to lift the vehicle to a 132 km altitude and a velocity of more than 4,900 m/sec. 

The CUS LOX/LH2 third stage then fired its 7.5 tonne thrust CE-7.5 engine one time for more than 12 minutes to finish the mission.  The 1.982 tonne satellite payload was accelerated toward a targeted 180 x 35,975 km x 19.3 deg orbit.  ISRO's CE-7.5 is a staged combustion engine designed to operate at 454 seconds specific impulse - more efficient than the Aerojet-Rocketdyne RL10A-4-1 engine that powers the Atlas 5 Centaur stage.  The fixed CE-7.5 engine is augmented by a pair of small steering engines.

An August, 2012 attempt to fly GLSV-D5 was thwarted by a second stage propellant leak during the early stages of the countdown.  Damage caused by the leak forced ISRO to roll back and dismantle the rocket.  Its core first stage and second stage were replaced entirely while its first stage liquid units were refurbished.

It was the third GSLV success in eight flights since 2001. 

Vehicle Configurations

(metric tons)
200 km x 45 deg
Configuration LIftoff
(metric tons)
GSLV 5 t 2 t 3 stage GSLV with
Russian 3rd Stage Engine
49 m 401 t
GSLV Mk2 5 t 2 t 3 stage GSLV Mk 2 with India's CUS-12 3rd stg 49 m 415 t
GSLV Mk2+ 5 t 2.25 t 3 stage GSLV Mk 2 with India's CUS-15 3rd stg 50.926 m 417.3 t

Vehicle Components

  Stage 1 Core
Mark 2
Stage 1 Core
Stage 1 (GS1)
L40 Strap-On
(Each of 4)
(Not Jettisoned)
Mark 2 Stage 1 (GS1)
L40Hs Strap-On
(Each of 4)
(Not Jettisoned)
Stage 2
Mark 2
Stage 2
Stage 3
Mark 2
Stage 3
Diameter (m) 2.8 m 2.8 m 2.1 m 2.1 m 2.8 m 2.8 m 2.8 m 2.8 m 3.40 m
Length (m) 20.3 m 20.1 m 19.7 m 19.7 m 11.6 m 11.6 m 8.7 m 8.7 m 7.86 m
Propellant Mass (tonnes) 129 t 138.2 t 40 t 42.6 t 37.5 t 39.5 t 12.5 t 12.8 t (CUS-12)
14.996 t (CUS-15)
Total Mass (tonnes) 156 t 166.5 t 46 t 48.2 t 42.8 t 45.0 t 15.0 t 15.3 t (CUS-12)
17.597 t (CUS-15)
Engine S125 S139 Viking 2 Vikas 2 Viking 4 Vikas 4 12KRB CE-7.5  
Oxidizer     N2O4 N2O4 N2O4 N2O4 LOX LOX  
(SL tonnes)
(Vac tonnes)
479.3 t 489.5 t 69.34 t 70.36 t 73.41 t 73.4 t 7.65 t 7.495 t (CUS-12)
7.77 t (CUS-15)
ISP (SL sec) 237 s 237 s 240 s 240 s          
ISP (Vac sec) 266 s 266 s 281 s 281 s 295 s 295 s 460 s 454 s  
Burn Time (sec) 100 s 100 s 160 s 148 s 150 s 150 s 750 s 720 s (CUS-12)
842 s (CUS-15)
No. Engines 1 1 1 each 1 each 1 1 1 1 1

Time Event Altitude Velocity
T-4.6 s L40 Strap-on Boosters Ignite 0 km 0
T+0 s S125 Core Stage Ignites - Liftoff 0 km 0
T+100 s S125 Core Stage Burn Out km  
T+158.4 s L40 Second Stage Ignites km  
T+160 s L40 First Stage Booster Burn Out/Stage Separation 73 km  
T+260 s Payload Fairing Separation 110 km  
T+310 s Second Stage Shut Down 120 km  
T+314 s Second/Third Stage Separation/Third Stage Ignition 127 km  
T +1024 s Third Stage Shut Down 195 km 10.2 km/s

GSLV Flight Record

04/18/01 GSLV      D01  GSAT 1       1.54   SR 1 [GTO-](1)
05/08/03 GSLV      D02  GSAT 2       1.80   SR 1  GTO
09/20/04 GSLV      F01  Edusat       2.00   SR 1  GTO
07/10/06 GSLV      F02  INSAT 4C     2.17   SR 2 [FTO](2)
09/02/07 GSLV      F04  INSAT 4CR    2.13   SR 2 [EEO](3)
04/15/10 GSLV Mk2  D03  GSAT 4       2.22   SR 2 [FTO](4)
12/25/10 GSLV      F06  GSAT-5P      2.31   SR 2 [FTO](5)
01/05/14 GSLV Mk2  D05  GSAT 14      1.98   SR 2  GTO (6)
08/27/15 GLSV Mk2  D06  GSAT 6       2.117  SR 2  GTO
09/08/16 GSLV Mk2  F05  INSAT 3DR    2.211  SR 2  GTO
05/05/17 GSLV Mk2  F09  GSAT 9       2.23   SR 2  GTO
03/29/18 GSLV Mk2  F08  GSAT 6A      2.14   SR 2  GTO
12/19/18 GSLV Mk2+ F11  GSAT 7A      2.25   SR 2  GTO+(7)
(1) Upper stage shut down early. Left GSAT-1 4,000 km short of planned GTO apogee.
(2) First stage liquid strap-on failed shortly after liftoff
(3) Launch vehicle placed INSAT-4CR in 168 x 31,786 km x 15.8 deg orbit, well 
short of planned 170 x 35,975 km x 21.7 deg GTO. Guidance error. 
(4) 3rd Stg failed at or near startup. First Indian Cryo Stage
(5) Control failed T+47 sec. RSO T+63 sec.
(6) ISRO's first indeginous cryo upper stage success.
(7) First indigenous CUS-15 upper stage.





 Last Update:  December 19, 2018