The Geosynchronous Satellite Launch Vehicle (usually known by its abbreviation, GSLV) is an expendable launch system operated by the Indian Space Research Organization (ISRO). It was developed to enable India to launch its INSAT-type satellites into geostationary orbit and to make India less dependent on foreign rockets.
The Indian Space Research Organization hopes to be ready to return its heavy-lift Geosynchronous Satellite Launch Vehicle (GSLV) to flight by March 2012.
The ISRO has undertaken corrective measures including redesigning the critical fuel booster turbo component of the indigenous cryogenic upper engine stage which malfunctioned causing the failure of the April 2010 mission.
A second GSLV failure, in December 2010, was attributed to faulty connectors and cables at the bottom of a Russian-supplied upper stage.
This failure caused the on-board computer near the top of the GSLV to lose communications with the control systems for the four L40 strap-on boosters that augment the rocket's first stage.
The April failure brought into question the future of the GSLV programme - and with it India's manned and Moon mission plans - as Russian-built stages are no longer available and so the Indian-designed and built stage has to be successful.
Previous Flights of GSLV
GSLV-F06 : Failed ( Dec. 25, 2010)
GSLV- D3 : development flight carrying GSAT 4 onboard; failed (Apr. 15, 2010)
GSLV- F02: 2nd operational flight of GSLV with INSAT- 4C onboard; failed ( July 10, 2006)
GSLV- F01: Sept. 2004, carried EDUSAT.
GSLV- D2 : carried GSAT-2
GSLV-D1: carrying GSAT-1; failed (March 2001)
The Chandrayaan-II Moon mission, scheduled for launch in 2013, and a crewed flight mission for 2016 will only happen if GSLV is ready.
Chairman K Radhakrishnan said ISRO is also setting up a major test facility for the qualification of a heavier cryogenic engine for GSLV-MK III, which is designed to place a four-tonne class satellite into a geostationary transfer orbit.
The two GSLV failures led ISRO to take a cautious approach to resuming launch operations, delaying a planned first-quarter 2011 mission for its workhorse Polar Satellite Launch Vehicle (PSLV).
That launch, of an uprated version of PSLV, was finally achieved on 15 July and, in a major boost for the Indian space programme, successfully launched India's homegrown communications satellite GSAT-12 after a smooth lift off from Satish Dhawan Space Centre on the island of Sriharikota on India's eastern coast.
Featuring four alternate liquid- and solid-fuel stages - including one of the world's largest sold-fuel boosters - the 44.9m PSLV is ISRO's first operational launch vehicle and has a sound track record of carrying out multiple launches, including a run of 17 successful flights.
The 1,410kg GSAT-12, carrying 12 Extended C-band transponders and designed for a lifespan of eight years, was launched by an XL version of PSLV, with a lift-off weight of 320 tonnes. The standard version is rated at 295 tonnes.
The XL version gets six, 12-tonne solid strap-ons in place of 9-tonne boosters for the standard version.
The 15 July flight was the second for an XL, following the October 2008 launch of India's first lunar mission Chandrayaan-1.