Polar Satellite Launch Vehicle
PSLV-C8 (CA Variant) carrying the AGILE x-ray and γ-ray astronomical satellite of the ASI lifting off from Sriharikota
|Function||Medium lift launch system|
|Country of origin||India|
|Height||44 metres (144 ft)|
|Diameter||2.8 metres (9 ft 2 in)|
|Mass||294,000 kilograms (650,000 lb)|
|3,250 kilograms (7,200 lb)|
|1,600 kilograms (3,500 lb)|
|1,410 kilograms (3,100 lb)|
|Partial failures||1 (PSLV)|
|First flight||PSLV: 20 September 1993
PSLV-CA: 23 April 2007
PSLV-XL: 22 October 2008
|Boosters (Stage 0)|
|Specific impulse||262 sec|
|Burn time||44 seconds|
|Specific impulse||269 sec|
|Burn time||105 seconds|
|Engines||1 Vikas (liquid)|
|Specific impulse||293 sec|
|Burn time||158 seconds|
|Specific impulse||294 sec|
|Burn time||83 seconds|
|Specific impulse||308 sec|
|Burn time||425 seconds|
The Polar Satellite Launch Vehicle (Hindi: ध्रुवीय उपग्रह प्रक्षेपण यान, Dhruvīya upagraha prakṣēpaṇa yāna), commonly known by its abbreviation PSLV, is an expendable launch system developed and 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 available only from Russia. PSLV can also launch small size satellites into geostationary transfer orbit (GTO). The PSLV has launched 62 satellites / spacecraft ( 27 Indian and 35 Foreign Satellites) into a variety of orbits so far. PSLV has a flyaway cost of 17 million USD for each launch.
PSLV was designed and developed at Vikram Sarabhai Space Centre (VSSC), Thiruvananthapuram, Kerala. The inertial systems are developed by ISRO Inertial Systems Unit (IISU) at Thiruvananthapuram. The liquid propulsion stages for the second and fourth stages of PSLV as well as the reaction control systems are developed by the Liquid Propulsion Systems Centre (LPSC), also at Thiruvananthapuram. The solid propellant motors are processed at Satish Dhawan Space Centre SHAR, which also carries out launch operations. After some delays, the PSLV had its first launch on 20 September 1993. Although all main engines performed as expected, an attitude 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.
PSLV continues to be the work horse of Indian satellite launches, especially for LEO satellites. It has undergone several improvements with each subsequent version, especially those involving thrust, efficiency as well as weight.
Vehicle description 
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 tonnes of Hydroxyl-terminated polybutadiene (HTPB) bound 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 tonnes 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. There are two additional small liquid engine control power plants in the first stage, the Roll Control Thrusters (RCT), fixed radially opposite one on each side, between the triplet set of strap-on boosters. RCT is used for roll control during the first stage and the SITVC in two strap-on motors is for roll control augmentation.
The second stage employs the Vikas engine and carries 41.5 tonnes (40 tonnes 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 tonnes 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 tonnes (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.
PSLV is developed with a group of wide-range control units.
|Stage 1||Stage 2||Stage 3||Stage 4|
|Pitch||SITVC||Engine Gimbal||Flex Nozzle||Engine Gimbal|
|Yaw||SITVC||Engine Gimbal||Flex Nozzle||Engine Gimbal|
|Roll||RCT and SITVC in 2 PSOMs||HRCM Hot Gas Reaction Control Motor||PS4 RCS||PS4 RCS|
ISRO has envisaged a number of variants of PSLV to cater to different mission requirements. There are currently three operational versions of the PSLV — the standard (PSLV), the core-alone (PSLV-CA) without the six strap-on booster motors, and the (PSLV-XL) version, which carries more solid fuel in its strap-on motors than the standard version. All the three versions have proved to be unalloyed successes. These configurations provide wide variations in payload capabilities ranging from 3800kg in LEO to 1800kg in sun synchronous orbit.
- PSLV (Operational)
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 1,678 kg to 622 km into sun synchronous orbit.
- PSLV-CA (Operational)
The PSLV-CA, CA meaning "Core Alone", model premiered on 23 April 2007. The CA model does not include the six strap-on boosters used by the PSLV standard variant. Two small roll control modules and two first stage motor control injection tanks were still attached to the side of the first stage. The fourth stage of the CA variant has 400 kg less propellant when compared to its standard version. It currently has capability to launch 1,100 kg to 622 km sun synchronous orbit.
- PSLV-XL (Operational)
PSLV-XL is the uprated version of Polar Satellite Launch Vehicle in its standard configuration boosted by more powerful, stretched strap-on boosters. Weighing 320 tonnes at lift-off, the vehicle uses larger strap-on motors (PSOM-XL) to achieve higher payload capability. PSOM-XL uses larger 13.5m, 12 tonnes of solid propellants instead of 9 tonnes used in the earlier configuration of PSLV. On 29 December 2005, ISRO successfully tested the improved version of strap-on booster for the PSLV. The first version of PSLV-XL was the launch of Chandrayaan-1 by PSLV-C11. The payload capability for this variant is 1800 kg compared to 1600 kg for the other variants. Other launches include the RISAT Radar Imaging Satellite and GSAT-12.
|PSLV-CA (Core Alone)||9||9||0||0|
- PSLV-HP (Under development / Proposed)
As reported on the website of The New Indian Express newspaper (26 April 2007), PSLV project director N Narayanamoorthy spoke of another version being planned called the PSLV-HP, standing for ‘high performance.’ It will have improved strap-ons motors, and the payload capability will be raised to 2000 kg. The HP version will be used to launch a constellation of seven navigation satellites between 2010 and 2012. Among other things, the efficiency of the stage 4 engine will be improved in this version.
- PSLV-3S (Under development / Proposed)
ISRO is also considering the development of a three-stage version of the rocket without six strap-on boosters (with the second stage of the four-stage version removed) which will be capable of placing 500 kg to LEO.
Launch history 
As of February 2013[update] the PSLV has made 23 launches, with 21 successful, one failure and one partial failure. All launches have occurred from the Satish Dhawan Space Centre, known before 2002 as the Sriharikota Range.
|Flight||Variant||Launch date/time (UTC)||Launch pad||Payload||Payload mass||Result||Note(s)|
|D1||PSLV||20 September 1993||First||IRS 1E||846 kg||Failure||Maiden flight; attitude control failure at second stage separation|
|D2||PSLV||15 October 1994||First||IRS-P2||804 kg||Success|
|D3||PSLV||21 March 1996||First||IRS-P3||920 kg||Success|
|C1||PSLV||29 September 1997||First||IRS 1D||1,250 kg||Partial failure||First operational flight; fourth stage underperformed resulting in lower than planned orbit|
|C2||PSLV||26 May 1999||First|| Oceansat-1
|Success||First commercial launch and first to carry multiple satellites|
|C3||PSLV||22 October 2001||First|| TES
|C4||PSLV||12 September 2002||First||METSAT 1 (Kalpana 1)||1,060 kg||Success||India's first launch to GTO, GTO payload capability has reached 1200kg from 2002 onward, compared to 1050 kg previously.|
|C5||PSLV||17 October 2003||First||ResourceSat 1||1,360 kg||Success||Launched in bad weather for political reasons.|
|C6||PSLV||5 May 2005||Second|| CartoSat 1
|Success||First PSLV launch from the second launch pad|
|C7||PSLV||10 January 2007||First|| CartoSat 2
|Success||First flight of hardware upgrade, first launch of reentry capsule (SRE)|
|C8||PSLV-CA||23 April 2007||Second|| AGILE
|Success||First flight of the 'Core-Alone' configuration.
ISRO's first exclusively commercial launch.
|C10||PSLV-CA||21 January 2008||First||TecSAR||295 kg||Success||ISRO's first fully commercially launch.|
|C9||PSLV-CA||28 April 2008||Second|| Cartosat-2A
|C11||PSLV-XL||22 October 2008||Second||Chandrayaan I||1,380 kg||Success||First flight of the PSLV-XL configuration, first Indian Lunar probe.|
|C12||PSLV-CA||20 April 2009||Second|| RISAT-2
|Success||India's first radar imaging satellite (RISAT).|
|C14||PSLV-CA||23 September 2009||First|| Oceansat-2
|Success||Rubin 9.1 and 9.2 intentionally remained attached to the fourth stage. SwissCube-1 was the first Swiss satellite, and ITUpSAT1 was the first satellite to be constructed in Turkey.|
|C15||PSLV-CA||12 July 2010||First|| Cartosat-2B
||AISSat-1 and TIsat are part of NLS-6.|
|C16||PSLV||20 April 2011||First|| ResourceSat-2
|C17||PSLV-XL||15 July 2011||Second||GSAT-12||1410 kg||Success||First use of Vikram flight computer.|
|C18||PSLV-CA||12 October 2011||First|| Megha-Tropiques
|C19||PSLV-XL||26 April 2012||First||RISAT-1||1850 kg||Success|
|C21||PSLV-CA||9 September 2012||First|| SPOT-6 (France)
||720 kg 15 kg||Success||nRESINS tested avionics for future PSLV launches|
|C20||PSLV-CA||25 February 2013||First|| SARAL
|Success||TUGSAT-1 and UniBRITE were the first Austrian satellites.|
|C22||PSLV-XL||12 June 2013 (1.01PM)||TBD||IRNSS-1||1380 kg||planned|
|C25 ||PSLV-XL||25 October 2013||TBD||Mangalyaan||planned|
Notable successful flights 
PSLV flight D1 
This was the first developmental flight of the PSLV. The IRS-1E satellite which was proposed to be launched was derived from the engineering model of IRS-1A incorporating a similar camera and an additional German-built monocular electro-optical stereo scanner. Even though the mission was a failure, the launch team and an expert committee appointed thereafter noted that the mission had validated many technologies and that most sub-systems had performed optimally.
PSLV flight C1 
PSLV flight C2 
In the flight sequence, IRS-P4 was injected first, followed by KITSAT-3 and DLR-TUBSAT in that order. The mission was supported by ISTRAC network of ground stations lcoated at Bangalore, Sriharikota, Lucknow, Mauritius, Bearslake, Russia and Biak, Indonesia. During the initial phase of the mission the ground station at Wilhem in Germany also provided network support. Upon injection of the satellites, data from the IRS-P4 was received at Hyderabad while KITSAT-3 data was received at the ground station in Korea and the data from the TUBSAT was received at the university ground station in Berlin.
PSLV flight C5 
The launch took place despite heavy rain which commenced half an hour before the scheduled launch. However, ISRO decided to go ahead with the launch as despite rain, there were no strong winds and there were weather reports suggested that the monsoons would set in by the next day. Following the launch, a press statement released by the Minister of State (Space) announced that the PSLV has been proposed for the Chandrayan 1 moon mission.
PSLV flight C6 
The President, Dr. Abdul Kalam, witnessed the launch from the Mission Control Centre. It was the first PSLV launch from second pad, using integrate-transfer-and-launch technology. After its integration in the Vehicle Assembly Building, the PSLV-C6 was transported on rails to the Umbilical Tower (UT) located one km away using the Mobile Launch Pedestal where the final operations were carried out.
PSLV flight C7 
- first use of DLA (Dual Payload Adapter) to launch 2 primary satellites in time
- reduction of propellant from 2.5 tonne to 2 tonne in the fourth liquid propellant stage
- incorporation of a video imaging system to capture payload and DLA separation events
- altitude based Day of Launch wind biased steering programme during Open Loop Guidance
- removal of Secondary Injection Thrust Vector Control (SITVC) system for one of the strapons ignited in the air.
PSLV flight C9 
The fourth stage first fired Cartosat-2A into orbit at an altitude of 637 km about 885 seconds after lift-off. About 45 seconds later, it propelled IMS-1 into the orbit. Then the six nano satellites belonging to a cluster called NLS-4 were injected into orbit at intervals of 20 seconds each. NLS-5, a single satellite, flew out and finally the tenth satellite Rubin-8 went along with the fourth stage into orbit. Two satellites belonged to India and the remaining were very small ones built by universities in different countries.
PSLV flight C21 
Launch attended by Prime Minister Manmohan Singh. mRESINS ( mini Redundant Strapdown Inertial Navigation System) bolted to the vehicle's fourth stage, have tested avionics for future PSLV missions.
Launch failures 
IRS 1E 
On September 20, 1993 a PSLV-D1 rocket has failed during launch. A significant attitude disturbance occured during second to third-stage separation, causing the attitude control command to exceed its maximum value. Because of the programming error in the pitch control loop of the digital autopilot software in the guidance and control processor, the required reversal of command polarity did not take place, causing the pitch loop to become unstable, resulted in loss of attitude control and failure to achieve orbit. Attitude disturbance was traced to failure of one of the retro rockets designed to pull the burnt second stage away from the third stage. Vehicle has crashed into the Bay of Bengal 700 seconds after take off.
IRS 1D 
On September 29, 1997 a PSLV-C1 rocket has failed during launch. Anomalous interaction between the primary and secondary pressure regulators of the fourth stage caused a reduction in propellant flow and thrust after 250 s of burn time. As a result, the fourth stage was shut down by a software override timer after burning 435 s, before reaching the target orbit or depleting propellant. The injection velocity was 140 m/s low, resulting in orbit 301x823 km instead of the planned 817 km circular SSO. Initially, a leak of helium gas from one of the components in the fourth stage was suspected, similar to recent Long march 3 launch failure, but later ruled out. Resulted orbit was partially corrected using satellite on-board thrusters, thereby raising the perigee to 737 km, while the apogee remained at 821 km.
See also 
- Polar Satellite Launch Vehicle
- ISRO's Website: ISRO's Launch Vehicle
- "PSLV". Encyclopedia Astronautica. Retrieved 2013-02-26.
- Subramanian, T.S. (15 July 2011). "The PSLV is a proud symbol of ISRO's self-reliance". The Hindu (Chennai, India).
- "PSLV Datasheet".
- "India's PSLV".
- PSLV-C11 Successfully Launches Chandrayaan-1
- "New Solid Propellant Motor to Increase PSLV Capability". ISRO.
- "Evolution of Indian launch vehicle technologies". Indian Academy of Sciences.
- "Current Science".
- International reference guide to space launch systems, Fourth Edition, p. 330, ISBN 1-56347-591-X
- "Successful lift off for PSLV-C5". Rediff.com. 17 October 2003. Retrieved 4 May 2012.
- PSLV-C8 blasts off with Italian payload
- First commercial launch of PSLV-C8 successful-India-The Times of India
- NDTV - ISRO Launches Israeli Satellite
- Delfi-C3 Mission status page
- PSLV Rocket Launches 10 Satellites
- PSLV C11
- T.S. Subramanian (23 October 2008). "Chandrayaan-1 bound for Moon". The Hindu. Retrieved 3 April 2013.
- PSLV C12
- India's spy in the sky: ISRO launches RISAT-2
- ISRO - CUBESATS
- PSLV-C14 lift-off today
- Oceansat 2, 6 nanosats launched in 20 mins by ISRO
- It's a First! Swiss Satellite In Space — This Cube Isn't Cheese
- First Turkish-Made Satellite Launched From India
- PSLV CA-C15 Countdown
- AISSat-1 Facts
- TIsat-1 Home
- "ISRO to launch five satellites on July 12". IANS. Sify. 3 July 2010. Retrieved 2010-07-03.
- NLS-6 Launch Blog
- More info
- T.S., Subramanian (19 April 2011). "PSLV-C16 launch today". The Hindu (Chennai, India). Retrieved 19 April 2011.
- ISRO-developed computer helped PSLV-C17 put satellite in orbit
- Megha-Tropiques / PSLV-C18 scheduled for take off on October 12, 2011 at 11:00:00 IST
- "VesselSat 1, 2, 3". Gunter's Space. Retrieved 2011-10-10.
- RISAT-1 satellite launch a ``grand success”: ISRO
- "Indian rocket launches asteroid hunter, 6 other satellites". NBC. 25 February 2013. Retrieved 25 February 2013.
- "India to launch seven satellites on February 25". DNA India. 15 February 2013. Retrieved 17 February 2013.
- Smartphone nanosatellite Space researchers at the University of Surrey's Surrey Space Centre (SSC) and SSTL have developed STRaND-1 "SSTL.co.uk" retrieved 14 Feb 2012
- "The Indian Herald".
- "Space Yuga".
- "Space Craft Encyclopedia".
- "Front Line".
- "Imperfect Ending". Digital Today.
- "The Indian Express".
- "Frontline: A remote-sensing success". The Hindu (Chennai, India).
- "Spaceref Asia: India's PSLV-C6 Successfully Launches Two Satellites".
- "ISRO: PSLV C7".
- "The Hindu: PSLV-C7 launch a success". Chennai, India. 11 January 2007.
- "PSLV puts 10 satellites in orbit". The Hindu. 29 April 2008. Retrieved 2013-02-28.
- "Isro's 100th mission: PSLV-C21 puts 2 foreign satellites in orbit". Time of India. Retrieved 9 September 2012.
- Indian PSLV successfully launches SPOT-6 for France NASA Spaceflight.com retrieved 12 Sep 2012
- International reference guide to space launch systems, Fourth Edition, p. 334, ISBN 1-56347-591-X
- Kyle, Ed. "India (SLV/ASLV/PSLV/GSLV) Flight History by Variant/Year (1979-2010)". Space Launch Report.
- Isro.Us - Space Exploration
- PSLV Moon Mission's Launch
- PSLV-C7 launch Video
- ISRO PSLV page
- Bharat-Rakshak PSLV page
- India in Space PSLV page
- PSLV-C8 Mission Photo Gallery
- News on PSLV C15 success