Geosynchronous Satellite Launch Vehicle

GeoSynchronous Satellite Launch Vehicle (Hindi: भूस्थिर उपग्रह प्रक्षेपण यान), abbreviated in English as GSLV, is an expendable launch system operated by the Indian Space Research Organisation (ISRO). It was developed to enable India to launch its satellites without dependence on foreign rockets and providers. GSLV has been used in nine launches to date, since its first launch in 2001 through to its most recent launch on August 27, 2015 of the GSAT-6.

History

The Geosynchronous Satellite Launch Vehicle (GSLV) project was initiated in 1990 with the objective of acquiring an Indian government launch capability for geosynchronous satellites. India has depended on the United States and Europe for the launch of INSAT class of satellites.

GSLV uses major components that are already proven in the Polar Satellite Launch Vehicle (PSLV) launchers in the form of the S125/S139 solid rocket booster and the liquid-fueled Vikas engine. The third stage was procured from Russian company Glavcosmos based on an agreement signed in 1991. Russia backed out of the deal after US sanctions were imposed in May 1992. ISRO started the Cryogenic Upper Stage Project in April 1994 and began developing its own cryogenic stage. Russia agreed to sell 7 cryogenic stages and 1 ground mock-up stage instead of 5 cryogenic stages and the technology to build the stages.

Launch vehicle

In spaceflight, a launch vehicle or carrier rocket is a rocket used to carry a payload from Earth's surface into outer space. A launch system includes the launch vehicle, the launch pad, and other infrastructure. Although a carrier rocket's payload is often an artificial satellite placed into orbit, some spaceflights, such as sounding rockets, are sub-orbital, while others enable spacecraft to escape Earth orbit entirely.

Earth orbital launch vehicles typically have at least two stages, and sometimes as many as four or more.

Types

Expendable launch vehicles are designed for one-time use. They usually separate from their payload and disintegrate during atmospheric reentry. In contrast, reusable launch vehicles are designed to be recovered intact and launched again. The Space Shuttle was the only launch vehicle with components used for multiple orbital spaceflights. SpaceX is developing a reusable rocket launching system for their Falcon 9 and Falcon Heavy launch vehicles. A second-generation VTVL design was announced in 2011. The low-altitude flight test program of an experimental technology-demonstrator launch vehicle began in 2012, with more extensive high-altitude over-water flight testing planned to begin in mid-2013, and continue on each subsequent Falcon 9 flight.Non-rocket spacelaunch alternatives are at the planning stage, although it is known that some companies are developing actual launch platforms, such as the Spanish zero2infinity with their rockoon-based launcher "bloostar".

Satellite Launch Vehicle

The Satellite Launch Vehicle (Hindi: उपग्रह प्रक्षेपण यान), or SLV was a project started in the early 1970s by the Indian Space Research Organisation to develop the technology needed to launch satellites. The project was headed by APJ Abdul Kalam. SLV was intended to reach a height of 400 km and carry a payload of 40 kg.The first experimental flight of SLV-3, in August 1979, was only partially successful.

It was a four-stage rocket with all solid-propellant motors.

The first launch of the SLV took place in Sriharikota on 10 August 1979. The fourth and final launch of the SLV took place on 17 April 1983.

Launch History

All four SLV launches occurred from the SLV Launch Pad at the Sriharikota High Altitude Range.

See also

References

Geosynchronous satellite

A geosynchronous satellite is a satellite in geosynchronous orbit, with an orbital period the same as the Earth's rotation period. Such a satellite returns to the same position in the sky after each sidereal day, and over the course of a day traces out a path in the sky that is typically some form of analemma. A special case of geosynchronous satellite is the geostationary satellite, which has a geostationary orbit – a circular geosynchronous orbit directly above the Earth's equator. Another type of geosynchronous orbit used by satellites is the Tundra elliptical orbit.

Geosynchronous satellites have the advantage of remaining permanently in the same area of the sky, as viewed from a particular location on Earth, and so permanently within view of a given ground station. Geostationary satellites have the special property of remaining permanently fixed in exactly the same position in the sky, as viewed from any location on Earth, meaning that ground-based antennas do not need to track them but can remain fixed in one direction. Such satellites are often used for communication purposes; a geosynchronous network is a communication network based on communication with or through geosynchronous satellites.