Geosynchronous Satellite Launch Vehicle
The stage is all set for the launch of the GSLV D3 from the Satish Dhawan Space Centre at Sriharikota at 4.27 pm today.
The 29-hour countdown for the lift-off began at 11.27 a.m. yesterday is progressing smoothly.
ISRO Spokesman Mr Satish has said that mandatory checks of the vehicle and charging of the batteries in both the rocket and the satellite are being undertaken during the countdown.
AIR correspondent reports that for the first time, the launch vehicle is powered by a totally indigenous cryogenic engine and will put an advanced communication satellite, GSAT-4, in orbit.
The GSAT-4 which weighs 2,220 kg will carry communication and navigation payloads. The communication payload Ka-band transponder will be used for wide-band multimedia services, e-commerce and high bandwidth Internet.
The navigation payload the GPS-aided Geo-Augmented Navigation (GAGAN) system will help commercial aircraft to land accurately in runways in poor visibility conditions.
History:
The Geosynchronous Satellite Launch Vehicle (GSLV) project was initiated in 1990 with the objective of acquiring launch capability for Geo-synchronous satellites. Until then, India depended on the former Soviet Union for the launch of heavy satellites.
GSLV uses major components that are already proven in the very successful PSLV launchers in the form of the S125/S139 solid booster and the Vikas L40/L35.5 liquid fuel motors. The first development flight of GSLV-Mk1 (GSLV-D1) was successfully launched on 18 April 2001.
Vehicle description:
The GSLV improved on the performance of the PSLV with the addition of liquid strap-on boosters and a cryogenic upper stage. It is a three-stage launch vehicle with the first stage being solid-propelled, the second liquid-propelled and the final stage being cryogenically propelled. The solid first and liquid second stages are carried over from the PSLV. Early GSLV launches used cryogenic upper stages supplied by Russia. India originally tried to buy the technology to build a cryogenic upper stage from Russia, but under pressure from the United States, that technology was not provided. Therefore, ISRO developed the cryogenic engine used in the GSLV indigenously.
The Geosynchronous Satellite Launch Vehicle (usually known by its abbreviation, GSLV) is an expendable launch system operated by the Indian Space Research Organisation (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 GSLV can place approximately 5000 kg (11,000 lbm) into an easterly low Earth orbit. Using the Russian 12KRB upper stage, with KVD-1 cryogenic rocket engine, GSLV can place 2200 kg (4,850 lbm) into an 18 degree geostationary transfer orbit.
Liquid boosters
The GSLV uses four L40 liquid strap-on boosters derived from the L37.5 second stage, which are loaded with 40 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 680 kN (150,000 lbf) of thrust.
First stage:
S139 stage is 2.8 m in diameter and is made of M250 grade maraging steel and it has a nominal propellant loading of 139 t.
Second stage:
The second stage is powered by the Vikas engine. It has 2.8 m diameter and uses 37.5 metric tons of liquid propellants with UDMH as fuel and nitrogen tetroxide (N2O4) as oxidizer, in two aluminium alloy compartments separated by a common bulk head. It delivers 720 kN (160,000 lbf) of thrust.
Third stage:
The third stage is a Cryogenic Rocket Engine, 2.8 m in diameter and uses liquid hydrogen (LH2) and liquid oxygen (LOX) in two separate tanks of aluminium alloy interconnected by an inter-stage. Propellant loading is 12.5 t. ISRO plans to use its own cryogenic engine from the fifth planned GSLV flight. On November 15, 2007 the indigenously developed "Cryogenic Upper Stage" was tested for 720 seconds, its full flight duration. The test was conducted at the Liquid Propulsion Systems Centre, ISRO's rocket engine test facility in Kerala. The testing qualified the flight stage for use on the next GSLV launch (GSLV-D3), scheduled to take place in 15th April 2010.
Variants:
Indian rockets: left to right; SLV, ASLV, PSLV, GSLV and GSLV-III
One of the strap-ons of GSLV-F04 being brought to the Vehicle Assembly Building
GSLV Mk.I
This variant had a 125 t (S-125) first stage and was capable of launching 1500 kg into geostationary transfer orbit.
GSLV Mk.I
This variant had 139 t (S-139) first stage and improved fuel in the strap-on boosters & second stage. This variant can launch 1900 kg into geostationary transfer orbit.
SLV Mk.II
GSLV Mk.II D3
This variant uses an Indian cryogenic engine and is capable of launching 2500 kg into geostationary transfer orbit.
The GSLV Mk.II D3 vehicle was be the first flight of the GSLV with an Indian cryogenic upper stage. Previous GSLV vehicles (GSLV Mk.I) have used Russian cryogenic engines.
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