Launch vehicles are used to transport and put satellites or spacecrafts into spaces. The first experimental Satellite Launch Vehicle (SLV-3) was developed in 1980.An augmented version of this, AS LV, 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). Currently India is using cryogenic technology for launching the satellites.
ISRO's Launch Fleet at a Glance:
- ISRO developed two experimental satellite launch vehicles, SLV-3 and ASLV.
- Polar Satellite Launch Vehicle (PSLV) commissioned in 1997.
- Geosynchronous Satellite Launch Vehicle (GSLV-Mk I) commissioned after second successful flight in May 2003.
- GSLV - MK II will use indigenously developed cryogenic upper stage.
- GSLV - MK III is under development.
Satellite Launch Vehicle-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.
- 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.
Augmented Satellite Launch Vehicle (ASLV)
- Augmented Satellite Launch Vehicle (AS LV) 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 1 m 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
The Polar Satellite Launch Vehicle (PSLV)
- 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 firststage motor, four of which are ignited on the ground and two are air-lit.
- There had been 16 continuously successful flights of PSLV, till July 2010. With its variant configurations, PSLV has proved its multi-payload
Geosynchronous Satellite Launch Vehicle (GSLV)
Geosynchronous Satellite Launch Vehicle (GSLV)- GSLV Mark 1&11 ,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-oris. 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 five 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.
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