Rocket system that boosts a spacecraft into Earth orbit or beyond Earth's gravitational pull. A wide variety of launch vehicles have been used to lift payloads ranging from satellites weighing a few pounds (or kilograms) to large modular components of space stations. Most launch vehicles are expendable (one-use) systems; many early ones were derived from intercontinental ballistic missiles (see ICBM). The Saturn V, which launched the spacecraft that carried humans to the Moon (see Apollo), had three stages (see staged rocket). The U.S. space shuttle system (from 1981) represents a significant departure from expendable launch vehicles in that it is partially reusable—its manned orbiting component is designed for numerous flights, and its solid rocket boosters can be recovered and refurbished.
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The Polar Satellite Launch Vehicle (usually known by its abbreviation, PSLV) is an expendable launch system operated by the Indian Space Research Organisation (ISRO). It was developed to allow India to launch its Indian Remote Sensing (IRS) satellites into sun synchronous orbits, a service that was, until the advent of the PSLV, commercially viable only from Russia. PSLV can also launch small size satellites into geostationary transfer orbit (GTO).
In september 2008 Indian scientists developed a path-breaking technology that has the potential to increase the range of missiles and satellite launch vehicles by at least 40%.The enhanced range is made possible by adding a special-purpose coating of chromium metal to the blunt nose cone of missiles and launch vehicles. This would add-up on the stated range.
The PSLV has four stages using solid and liquid propulsion systems alternately. The first stage is one of the largest solid-fuel rocket boosters in the world and carries 138 metric tonnes of Hydroxyl-terminated polybutadiene (HTPB) binded propellant with a diameter of 2.8 m. The motor case is made of maraging steel. The booster develops a maximum thrust of about 4,430 kN. Six strap-on motors, four of which are ignited on the ground, augment the first stage thrust. Each of these solid propellant strap-on motors carries nine metric tonne of HTPB propellant and produces 677 kN thrust. Pitch and yaw control of the PSLV during the thrust phase of the solid motor is achieved by injection of an aqueous solution of strontium perchlorate in the nozzle to constitute Secondary Injection Thrust Vector Control System (SITVC). The injection is stored in two cylindrical aluminum tanks strapped to the solid rocket motor and pressurized with nitrogen. SITVC in two strap-on motors is for roll control augmentation.
The second stage employs the Vikas engine and carries 41.5 metric tonne (40 metric tonne till C-5 mission) of liquid propellant Unsymmetrical Di-Methyl Hydrazine (UDMH) as fuel and Nitrogen tetroxide (N2O4) as oxidizer. It generates a maximum thrust of 800 kN (724 till C-5 mission). Pitch & yaw control is obtained by hydraulically gimbaled engine (±4°) and two hot gas reaction control for roll.
The third stage uses 7 metric tonne of HTPB-based solid propellant and produces a maximum thrust of 324 kN. It has a Kevlar-polyamide fiber case and a submerged nozzle equipped with a flex-bearing-seal gimbaled nozzle (±2°) thrust-vector engine for pitch & yaw control. For roll control it uses the RCS (Reaction Control System) of fourth stage.
The fourth and the terminal stage of PSLV has a twin engine configuration using liquid propellant. With a propellant loading of 2 metric tonne (Mono-Methyl Hydrazine as fuel + Mixed Oxides of Nitrogen as oxidiser), each of these engines generates a maximum thrust of 7.4 kN. Engine is gimbaled (±3°) for pitch, yaw & roll control and for control during the coast phase uses on-off RCS. PSLV-C4 used a new lightweight carbon composite payload adapter to enable a greater GTO payload capability.
The polar satellite was launched on February 24th.
The standard version of the PSLV has four stages using solid and liquid propulsion systems alternately and six strap-on boosters. It currently has capability to launch 1,600 kg to 622 km sun synchronous orbit. PSLV-CA
The PSLV-CA, with CA meaning "Core Alone", uses the core stages without any strap-on boosters. It currently has capability to launch 1,100 kg to 622 km sun synchronous orbit.
After some delays, the PSLV had its first launch on 20 September 1993. Although all main engines performed as expected, an altitude control problem was reported in the second and third stages. After this initial setback, ISRO met complete success with the third developmental launch in 1996. Further successful launches followed in 1997, 1999, and 2001.
On May 5, 2005, PSLV-C6 launched two satellites into orbit; CARTOSAT-I a stereoscopic Earth observation satellite with cartographic applications, weighing 1560 kg, and HAMSAT providing satellite based radio service for amateur radio operators, weighing 42.5 kg into a high polar orbit (632 x 621 km).
PSLV will continue be the work horse of the ISRO for its launches, especially for LEO satellites and the Chandrayaan Projects. It has undergone several improvements with each subsequent version, especially those involving thrust, efficiency and weight.
On January 10, 2007, the PSLV-C7 carried four satellites - the 680 kg Indian remote sensing satellite CARTOSAT-2, the 550 kg Space Capsule Recovery Equipment (SRE-1), Indonesia's LAPAN-TUBSAT (60kg) and Argentina's 6 kg nanosatellite called NANO PEHUENSAT-1 into orbit.
On April 23, 2007, the PSLV-C8 carried its first commercial satellite, the Agile for the Italian Space Agency as main payload with the Advanced Avionics Module as its secondary payload Successfully. This was ISRO's first purely commercial launch. All launches of foreign satellites before this had been of micro-satellites or light weight satellites piggybacked on the PSLV, with an Indian satellite being the primary payload. The PSLV-C8 was also launched without its regular 6 strap-on boosters. Another first for ISRO was the inclination of 2.5o (equatorial orbit), which made launch comparatively riskier than usual.
On 28 April 2008, PSLV-C9 launched ten satellites, the most number ISRO has deployed in one launch. PSLV-C9 placed on orbit an imaging satellite Cartosat-2A India, technology demonstrator IMS-1/TWSAT, and a cluster of eight nanosatellites from different countries. The launch is reported a success.
|Vehicle||Variant||Date of Launch||Launch Location||Payload||Mass||Mission Status||Note(s)|
|D1||PSLV||20 September 1993||Sriharikota||IRS 1E||845 kg||Failure||First development flight. Software error causes vehicle crash in to the Bay of Bengal (700 seconds after take off)|
|D2||PSLV||15 October 1994||Sriharikota||IRS P2||904 kg||Success||First successful development flight|
|D3||PSLV||21 March 1996||Sriharikota||IRS P3||920 kg||Success|
|C1||PSLV||29 September 1997||Sriharikota||IRS 1D||1,200 kg||Failure||Suboptimal injection of Satellite|
|C2||PSLV||26 May 1999||Sriharikota|| OceanSat 1|
|1,198 kg||Success||First successful commercial flight.|
|C3||PSLV||22 October 2001||Sriharikota|| TES ||1,294 kg||Success|
|C4||PSLV||12 September 2002||Sriharikota||METSAT 1 (Kalpana 1)||1,055 kg||Success|
|C5||PSLV||17 October 2003||Sriharikota||ResourceSat 1||1,360 kg||Success|
|C6||PSLV||5 May 2005||Sriharikota*|| CartoSat 1|
|C7||PSLV||10 January 2007||Sriharikota|| CartoSat 2|
|1,210 kg||Success||Used a device called Dual Launch Adapter for the first time to launch four satellites. Used for the first time a video imaging system on board to take pictures of the separation of the first three satellites from the fourth stage of rocket.|
|C8||PSLV-CA||23 April 2007||Sriharikota*|| AGILE|
|537 kg||Success||First flight of the 'core-alone' version|
|C10||PSLV-CA||21 January 2008||Sriharikota||TECSAR||260 kg||Success|
|C9||PSLV-CA||28 April 2008||Sriharikota*|| Cartosat-2A|
|800 kg||Success||The most satellites (10) launched at once by the PSLV.|
|C11||PSLV-XL||22nd October 2008||Sriharikota||Chandrayaan I||1304 kg||Planned|