Geosynchronous Satellite Launch Vehicle

History

The Geosynchronous Satellite Launch Vehicle (GSLV) project was initiated in 1990 with the objective of acquiring an Indian 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.

The first development flight of GSLV Mk.I (GSLV-D1) was launched on 18 April 2001. The flight carrying GSAT-1 failed to reach the correct orbit. Attempts to save GSAT-1 by using its own propulsion system to maneuver it into the correct orbit were unsuccessful as it ran out of fuel several thousand kilometres below geosynchronous orbit.

The GSLV became operational after a second development flight, which successfully placed GSAT-2 in 2003. In its first operational flight in September 2004, GSLV launched EDUSAT - India's first dedicated satellite for educational services. However, the second operational flight, GSLV F02, conducted on July 10, 2006 did not succeed in placing the satellite INSAT-4C into orbit.

GSLV F04 is the fifth flight of India's Geosynchronous Satellite Launch Vehicle (GSLV), launched INSAT-4CR satellite, into a geosynchronous transfer orbit (GTO) of 170 km perigee and 35,975 km apogee with an orbital inclination of 21.7° with respect to the equator on 2 September 2007. Subsequently, the satellite was maneuvered into geostationary orbit using its own propulsion system.

Two launches in 2010 failed; the first, in April 2010, was the first flight of the GSLV Mk.II, with an Indian-developed third stage engine replacing the Russian engine used on earlier flights. The third stage failed to ignite. The next launch, in December 2010, used the Russian engine, however the vehicle went out of control during first stage flight and was destroyed by range safety.

GSLV-D5, launched on 5 January 2014, was the first successful flight of the GSLV Mark.II using the indigenously developed cryogenic engine, the CE-7.5.

GSLV-F05 successfully launched from Sriharikota at 16:50 on September 8, 2016 carrying 2211 kg satellite INSAT-3DR and the satellite has been placed at GTO 1024 seconds after launch.

Vehicle description

The 49 metres (161 ft) tall GSLV, with a lift-off mass of 415 tonnes (457 tons), is a three-stage vehicle with solid, liquid and cryogenic stages respectively. The payload fairing, which is 7.8 metres (26 ft) long and 3.4 metres (11 ft) in diameter, protects the vehicle electronics and the spacecraft during its ascent through the atmosphere. It is discarded when the vehicle reaches an altitude of about 115 km.

GSLV employs S-band telemetry and C-band transponders for enabling vehicle performance monitoring, tracking, range safety / flight safety and preliminary orbit determination. The Redundant Strap Down Inertial Navigation System/Inertial Guidance System of GSLV housed in its equipment bay guides the vehicle from lift-off to spacecraft injection. The digital auto-pilot and closed loop guidance scheme ensure the required altitude maneuver and guide injection of the spacecraft to the specified orbit.

The GSLV can place approximately 5,000 kg (11,000 lb) into an easterly low Earth orbit. With the GSLV Mk.I, using the Russian 12KRB upper stage, with KVD-1 cryogenic rocket engine, GSLV can place 2,200 kg (4,900 lb) into an 18° geostationary transfer orbit. The GSLV Mk.II uses an indigenous cryogenic engine, the CE-7.5 in the third stage instead of the Russian cryogenic engine.

Liquid boosters

The first GSLV flight, GSLV-D1 used the L40 engine. Subsequent flights of the GSLV used high pressure engines in the strap-on boosters called the L40H. The GSLV uses four L40H liquid strap-on boosters derived from the L37.5 second stage, which are loaded with 42.6 tons of hypergolic propellants (UDMH & N₂O₄). The propellants are stored in tandem in two independent tanks 2.1 m diameter. The engine is pump-fed and generates 760 kN (150,000 lbf) of thrust, with a burn time of 150 seconds.

First stage

GSLV-D1 used the S125 stage which contained 125 tonnes of solid propellant and had a burn time of 100 seconds. All subsequent launches have used enhanced propellant loaded S139 stage. The S139 stage is 2.8 m in diameter and has a nominal burn time of 109 seconds. The stage generates a maximum thrust of 4700 kN.

Second stage

The GS2 stage is powered by the Vikas engine. It has 2.8 m diameter.

Third stage

The third stage of the GSLV Mk.II is propelled by the CE-7.5, an indigenous cryogenic rocket engine, 2.8 m in diameter and uses liquid hydrogen (LH2) and liquid oxygen (LOX) The indigenous cryogenic engine was built at the Liquid Propulsion Systems Centre in Valiamala, Kerala & Mahendragiri, Tamil Nadu. This makes India one of the 6 countries which are capable of producing cryogenic engines. The engine has a default thrust of 7.5 tons (75 kN) but is capable of a maximum thrust of 9.31 tons (93.1 kN).

Variants

GSLV rockets using the Russian Cryogenic Stage (CS) are designated as the GSLV Mk I while versions using the indigenous Cryogenic Upper Stage (CUS) are designated the GSLV Mk II. All GSLV launches have been conducted from the Satish Dhawan Space Centre in Sriharikota.

GSLV Mk I (a)

This variant had a 125 t (S-125) first stage and was capable of launching 1500 kg into geostationary transfer orbit. This variant is retired.

GSLV Mk I (b)

This variant had 139 t (S-139) first stage and improved fuel in the strap-on boosters and second stage. This variant can launch 1900 kg into geostationary transfer orbit.

GSLV Mk I (c)

This variant has a 15 tonne propellant loading in the third stage, called the C-15. GSLV-F06 (flight 6) is the only attempted launch of the Mark I(c) version to date.

GSLV Mk II

This variant uses an Indian cryogenic engine, the CE-7.5, and is capable of launching 2500 kg into geostationary transfer orbit. Previous GSLV vehicles (GSLV Mk.I) have used Russian cryogenic engines.