GSLV - Geosynchronous Satellite Launch Vehicle

	Geosynchronous Satellite Launch Vehicle(GSLV)-Mark I&II ,is capable of placing INSAT–II class of satellites (2000 – 2,500 kg) into Geosynchronous Transfer Orbit (GTO). GSLV is a three stage vehicle GSLV is 49 m tall, with 414 t lift off weight. It has a maximum diameter of 3.4 m at the payload fairing. First stage comprises S125 solid booster with four liquid (L40) strap-ons. Second stage (GS2) is liquid engine and the third stage (GS3) is a cryo stage. The vehicle develops a lift off thrust of 6573 kn.
	The first flight of GSLV took place from SHAR on April 18, 2001 by launching 1540 kg GSAT-1. It was followed by four more launches , GSLV-D2 on May 8, 2003 (GSAT-2 1825 kg), GSLV-F01 on September 20, 2004 (EDUSAT 1950 kg), GSLV-F02 on July 10, 2006, GSLV-F04 on September 2, 2007 (INSAT-4CR 2130 kg) and GSLV-D3 on April 15, 2010.
	Typical Parameters of GSLV Lift-off weight 414 tonne Pay Load 2 to 2.5 Tonne in to Geosynchronous Transfer Orbit (GTO) Height 49 metre

Source: isro.org

PSLV - Polar Satellite Launch Vehicle

Source : isro.org
	The Polar Satellite Launch Vehicle,usually known by its abbreviation PSLV is the first operational launch vehicle of ISRO. PSLV is capable of launching 1600 kg satellites in 620 km sun-synchronous polar orbit and 1050 kg satellite in geo-synchronous transfer orbit. In the standard configuration, it measures 44.4 m tall, with a lift off weight of 295 tonnes. PSLV has four stages using solid and liquid propulsion systems alternately. The first stage is one of the largest solid propellant boosters in the world and carries 139 tonnes of propellant. A cluster of six strap-ons attached to the first stage motor, four of which are ignited on the ground and two are air-lit.
	The reliability rate of PSLV has been superb. There had been 15 continuously successful flights of PSLV, till September 2009. With its variant configurations, PSLV has proved its multi-payload, multi-mission capability in a single launch and its geosynchronous launch capability. In the recent Chandrayaan-mission, another variant of PSLV with an extended version of strap-on motors, PSOM-XL, the payload haul was enhanced to 1750 kg in 620 km SSPO. PSLV has rightfully earned the status of workhorse launch vehicle of ISRO.
	Typical Parameters of PSLV Lift-off weight 295 tonne Pay Load 1600 kg in to 620 km Polar Orbit, 1060 kg in to Geosynchronous Transfer Orbit (GTO) Height 44 metre

ISRO's Launch Fleet - ASLV

ASLV
Augmented Satellite Launch Vehicle (ASLV) was developed to act as a low cost intermediate vehicle to demonstrate and validate critical technologies. With a lift off weight of 40 tonnes, the 23.8 m tall ASLV was configured as a five stage, all-solid propellant vehicle, with a mission of orbiting 150 kg class satellites into 400 km circular orbits. The strap-on stage consisted of two identical 1m diameter solid propellant motors, Under the ASLV programme four developmental flights were conducted. The first developmental flight took place on March 24, 1987 and the second on July 13, 1988. ASLV-D3 was successfully launched on May 20, 1992, when SROSS-C (106 kg) was put into an orbit of 255 x 430 km. ASLV-D4, launched on May 4, 1994, orbited SROSS-C2 weighing 106 kg. It had two payloads, Gamma Ray Burst (GRB) Experiment and Retarding Potentio Analyser (RPA) and functioned for seven years. ASLV provided valuable inputs for further development. Source : isro.org

ISRO's Launch Fleet - SLV-3

SLV-3

Satellite Launch Vehicle-3 (SLV-3), India's first experimental satellite launch vehicle was successfully launched on July 18, 1980 from SHAR Centre Sriharikota, when Rohini satellite, RS-1, was placed in orbit. SLV-3 was a 22 m long, all solid, four stage vehicle weighing 17 tonnes capable of placing 40 kg class payloads in low earth orbit. It employed an open loop guidance (with stored pitch programme) to steer the vehicle in flight along pre-determined trajectory. The first experimental flight of SLV-3, in August 1979, was only partially successful. Apart from the July 1980 launch, there were two more launches held in May 1981 and April 1983, orbiting Rohini satellites carrying remote sensing sensors. Source : isro.org

ISRO's Landmark achievements in Launch Vehicle Development

• PSLV has 15 consecutively successful flights out of 16 launches.

• PSLV used for launching a total of 22 satellites for foreign customers under commercial agreements, demonstrating its multi-satellite launch capability.

• PSLV used to launch Space Capsule Recovery Experiment (SRE-1), Chandrayan - 1 and ISRO's exclusive meteorological satellite, KALPANA - 1, proving its versatility.

• GSLV with four successful flights of six launches can launch 2 to 2.5 tonne satellite into Geo-synchronous Transfer Orbit (GTO)

• Successful testing of indigenously developed cryogenic upper stage on November 15, 2007.

Source: isro.org

Launch Vehicles - A Glimpse

Launch Vehicles are used to transport and put satellites or spacecrafts into space. In India, the launch vehicles development programme began in the early 1970s. The first experimental Satellite Launch Vehicle (SLV-3) was developed in 1980. An Augmented version of this, ASLV, was launched successfully in 1992. India has made tremendous strides in launch vehicle technology to achieve self-reliance in satellite launch vehicle programme with the operationalisation of Polar Satellite Launch Vehicle (PSLV) and Geosynchronous Satellite Launch Vehicle (GSLV).

PSLV represents ISRO's first attempt to design and develop an operational vehicle that can be used to orbit application satellites. While SLV-3 secured for India a place in the community of space-faring nations, the ASLV provided the rites of passage into launch vehicle technology for ISRO. And with PSLV, a new world-class vehicle has arrived. PSLV has repeatedly proved its reliability and versatility by launching 30 satellites / spacecrafts (14 Indian and 16 for international customers) into a variety of orbits so far.

ISRO also makes the Rohini series of sounding rockets used by the Indian and international scientific community to launch payloads to various altitudes for atmospheric research and other scientific investigations. These rockets are also used to qualify some of the critical systems used for advanced launch vehicles.


Source: isro.org