Polar Satellite Launch Vehicle
The Polar Satellite Launch Vehicle ( PSLV short, Hindi, ध्रुवीय उपग्रह प्रक्षेपण यान ) is an Indian launch vehicle for light to medium weight payloads. The missile is launched from the Indian Space Agency ISRO Satish Dhawan from the spaceport at Sriharikota Space Centre. PSLV was developed to launch Indian IRS - Earth observation satellites with their own rockets, since it was there previously dependent on the Soviet Union and Russia, and its carrier.
The first launch took place in 1993, but was not successful. Although the first stage operated without any problem, occurred in the second and the third step, an error in the height control system, leading to a crash of the rocket. After about a year successfully launched the second PSLV. Since then, several PSLV both Indian as well as additional smaller foreign payloads successfully launched into space. The first Indian spacecraft Chandrayaan -1 was launched with a PSLV to the moon in 2008.
PSLV is a four-stage missile, consisting of two solid levels (first and third stage ), and two liquid-propellant stages ( second and fourth stages ). In addition, the first stage is supported in the base version of six small solid boosters. In the version PSLV -CA (Core Alone) are omitted this, what the payload capacity of 1100 kg into a sun-synchronous orbit. The first stage is one of the largest solid rocket boosters in the world and burns HTPB (hydroxyl Terminated Poly Butadiene ) as fuel. The first stage contained only 129 tonnes of fuel until the third start ( PSLV - Dx) and was then increased to 138 t ( PSLV -Cx ), where from the PSLV - C4 also the maximum thrust was increased from 4430 to 4628 kN. It is also used as the first stage of the larger and more powerful GSLV. The boosters are filled with HTPB solid fuel rockets, which are fired consecutively (first four, then the remaining two ). The second stage burns liquid fuel and is powered by a Vikas engine, which is a product manufactured under license Viking -4A engine of European Ariane 3. The third stage also burns HTPB. The fourth stage has two engines that burn fuel combination of monomethyl hydrazine and nitrogen tetroxide.
The height of the rocket is 44.4 m, the take-off mass 294 t (data for PSLV - C6). Since the first launch in 1993, the rocket has been constantly strengthened and improved, so that the version in use today, over 1,600 kilograms in an approximately 600 km high polar orbit can bring ( Erststartversion about 850 kg) and about 1000 kg into a geostationary transfer orbit. The last version ( the PSLV -XL) has improved booster and can even bring 1800 kg into polar orbit. The first launch of this version took place on 22 October 2008 for Chandrayaan -1. To start the Satish Dhawan Space Centre rocket has two starting systems, the second (SLP - Second Launch Pad ) was inaugurated with the launch of PSLV - C6 rocket in 2005.
At the start of the PSLV - C17, a computer system was used for the first time, which used exclusively by Indian type processors Vikram 1601 in two redundant control computer. This had been tested in 2009 at the start of the PSLV - C12, where they were used in one of the two systems.