The Polar Satellite Launch Vehicle, 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 in 1993, commercially available only from Russia. PSLV can also launch small size satellites into geostationary transfer orbit (GTO).[6]

Some notable payloads launched by PSLV include India's first lunar probe Chandrayaan-1, India's first interplanetary mission, Mars Orbiter Mission (Mangalyaan) and India's first space observatory, Astrosat.[1]

PSLV has gained credence as a small satellite launcher due its numerous multi-satellite deployment campaigns with auxiliary payloads usually ride sharing along an Indian primary payload. Most notable among these was launch of PSLV C37 on 15 February 2017 successfully deploying 104 satellites in sun-synchronous orbit, tripling the previous record held by Russia for most number of satellites sent to space on a single launch.[7][8]

Payloads can be integrated in tandem configuration employing a Dual Launch Adapter.[9][10] Smaller payloads are also placed on equipment deck and customized payload adapters.[11]


PSLV was designed and developed in the early 1990s at Vikram Sarabhai Space Centre near Thiruvananthapuram, Kerala. The inertial navigation 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 (RCS) are developed by the Liquid Propulsion Systems Centre (LPSC) at Mahendragiri near Tirunelveli, Tamil Nadu. The solid propellant motors are processed at Satish Dhawan Space Centre (SHAR) at Sriharikota, Andhra Pradesh which also carries out launch operations.

The PSLV was first launched on 20 September 1993. The first and second stages performed as expected, but an attitude control problem led to the collision of the second and third stages at separation, and the payload failed to reach orbit.[12] After this initial setback, the PSLV successfully completed its second mission in 1994.[13] The fourth launch of PSLV suffered a partial failure in 1997, leaving its payload in a lower than planned orbit. Since then, the PSLV has launched 34 times with no further failures.[14]

PSLV continues to support Indian and foreign satellite launches especially for low Earth orbit (LEO) satellites. It has undergone several improvements with each subsequent version, especially those involving thrust, efficiency as well as weight. In November 2013, it was used to launch the Mars Orbiter Mission, India's first interplanetary probe.[15]

ISRO is planning to privatise the operations of PSLV and will work through a joint venture with private industries. The integration and launch will be managed an industrial consortium through Antrix Corporation.[16]

Vehicle description

PSLV Scale Down Model

The PSLV has four stages using solid and liquid propulsion systems alternately. The first stage, one of the largest solid rocket boosters in the world, carries 138 t (304,000 lb) tonnes of hydroxyl-terminated polybutadiene-bound (HTPB) propellant and develops a maximum thrust of about 4,800 kilonewtons (1,100,000 lbf). The 2.8 m (9 ft 2 in) diameter motor case is made of maraging steel and has an empty mass of 30,200 kilograms (66,600 lb).[5] Pitch and yaw control during first stage flight is provided by the Secondary Injection Thrust Vector Control System (SITVC), which injects an aqueous solution of strontium perchlorate into the nozzle to produce asymmetric thrust. The solution is stored in two cylindrical aluminium tanks strapped to the solid rocket motor and pressurised with nitrogen. Roll control is provided by two small liquid engines on opposite sides of the stage, the Roll Control Thrusters (RCT).

On the PSLV and PSLV-XL, first stage thrust is augmented by six strap-on solid boosters. Four boosters are ground-lit and the remaining two ignite 25 seconds after launch. The solid boosters carry 9 t (20,000 lb) or 12 t (26,000 lb) (for PSLV-XL configuration) propellant and produce 510 kN (110,000 lbf) and 719 kN (162,000 lbf) thrust respectively. Two strap-on boosters are equipped with SITVC for additional attitude control.[5] The PSLV-CA uses no strap-on boosters.

The second stage employs the Vikas engine and carries 41.5 t (91,000 lb) of liquid propellant – unsymmetrical dimethylhydrazine (UDMH) as fuel and nitrogen tetroxide (N2O4) as oxidiser. It generates a maximum thrust of 800 kN (180,000 lbf). The engine is hydraulically gimbaled (±4°) to provide pitch and yaw control, while roll control is provided by two hot gas reaction control motors.

The third stage uses 7 t (15,000 lb) of hydroxyl-terminated polybutadiene-based solid propellant and produces a maximum thrust of 240 kN (54,000 lbf). It has a Kevlar-polyamide fibre case and a submerged nozzle equipped with a flex-bearing-seal gimbaled nozzle (±2°) thrust vector engine for pitch & yaw control. Roll control is provided by the fourth stage reaction control system (RCS).[5]

The fourth stage is powered by twin engines burning monomethylhydrazine (MMH) and mixed oxides of nitrogen (MON). Each engine generates 7.4 kN (1,700 lbf) thrust and is gimbaled (±3°) to provide pitch, yaw & roll control during powered flight. Coast phase attitude control is provided by RCS. The stage carries 2,500 kg (5,500 lb) of propellant in the PSLV and PSLV-XL and 2,100 kg (4,600 lb) in the PSLV-CA.[17]

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.[18] These configurations provide wide variations in payload capabilities upto 3,800 kg (8,400 lb) in LEO and 1,800 kg (4,000 lb) in sun-synchronous orbit.


The standard version of the PSLV (PSLV-G) has four stages using solid and liquid propulsion systems alternately and six strap-on boosters. It currently has capability to launch 1,678 kg (3,699 lb) to 622 km (386 mi) into sun-synchronous orbit.


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.[17] The fourth stage of the CA variant has 400 kg (880 lb) less propellant when compared to its standard version.[17] It currently has capability to launch 1,100 kg (2,400 lb) to 622 km (386 mi) Sun synchronous orbit.[19]


PSLV-XL is the upgraded version of Polar Satellite Launch Vehicle in its standard configuration boosted by more powerful, stretched strap-on boosters.[17] Weighing 320 t (710,000 lb) at lift-off, the vehicle uses larger strap-on motors (PSOM-XL) to achieve higher payload capability. [20] On 29 December 2005, ISRO successfully tested the improved version of strap-on booster for the PSLV. The first use of PSLV-XL was the launch of Chandrayaan-1 by PSLV C11. The payload capability for this variant is 1,800 kg (4,000 lb) to SSO.[19] Other launches include the RISAT (Radar Imaging Satellite) and GSAT-12.[21]

Variant Launches Successes Failures Partial failures
PSLV (Standard) 12 10 1 1
PSLV-CA (Core Alone) 11 11 0 0
PSLV-XL (Extended)[1] 19 18 1 0
PSLV-3S (Concept)

PSLV-3S was conceived as a three-staged version of PSLV with its six strap-on boosters and second liquid stage removed. The total lift-off mass of PSLV-3S was expected to be 175 tonnes with capacity to place 500 kg in 550 km low Earth orbit.[19][22][23][24][25]

Launch history

See also


  1. ^ a b c d e f "Polar Satellite Launch Vehicle". Retrieved 2014-12-21. 
  2. ^ "Access to Space" (PDF). 2011. Retrieved March 8, 2017. 
  3. ^ "ISRO at India Mobile Congress 2017". Retrieved September 29, 2017. 
  4. ^ a b c d e f g h i j k l m n o "PSLV-C37 Brochure". ISRO. 
  5. ^ a b c d e "PSLV Launch Vehicle Information". Spaceflight 101. Retrieved February 20, 2015. 
  6. ^ "Welcome To ISRO :: Launch Vehicles". Retrieved 2014-04-08. 
  7. ^ Barry, Ellen (2017-02-15). "India Launches 104 Satellites From a Single Rocket, Ramping Up Space Race". The New York Times. ISSN 0362-4331. Retrieved 2017-02-15. 
  8. ^ "ISRO's record satellites' launch: 10 top facts - Times of India". The Times of India. Retrieved 2017-02-15. 
  9. ^ "PSLV C35 / Scatsat-1 with Dual Launch Adapter". Retrieved 19 December 2017. 
  10. ^ Cong, Indian Science (6:15 AM - 5 Jan 2016). "Here's the #103ISC Official Newsletter 2nd edition brought by Journalism students and researchers. 2/2 @PIB_Indiapic.twitter.com/mLq9CZnY5T". @103ISC. Retrieved 2017-12-19.  Check date values in: date= (help)
  11. ^ "The DMC3 Constellation launch in photos". Retrieved 19 December 2017. 
  12. ^ "India (Launchers)". Spacecraft Encyclopedia. Retrieved 12 November 2014. 
  13. ^ "PSLV (1)". Gunter's Space Page. Retrieved 12 November 2014. 
  14. ^ "PSLV". Gunter's Space Page. Retrieved 12 November 2014. 
  15. ^ "Welcome To ISRO :: Mars Orbiter Mission". Retrieved 2014-04-08. 
  16. ^ "ISRO looks at JV for PSLV manufacture; launch to be privatized by 2020". Geospatial World. 2017-10-26. Retrieved 2017-10-26. 
  17. ^ a b c d "PSLV Datasheet". 
  18. ^ Subramanian, T.S. (15 July 2011). "The PSLV is a proud symbol of ISRO's self-reliance". The Hindu. Chennai, India. 
  19. ^ a b c "India's PSLV" (PDF). www.earth2orbit.com. 15 March 2009. Archived from the original (PDF) on 10 July 2011. 
  20. ^ PSLV-C11 Successfully Launches Chandrayaan-1 Archived 25 October 2008 at the Wayback Machine.
  21. ^ "New Solid Propellant Motor to Increase PSLV Capability". ISRO. 
  22. ^ "Evolution of Indian launch vehicle technologies" (PDF). www.ias.ac.in. Indian Academy of Sciences. 25 Dec 2007. Archived from the original (PDF) on 24 May 2011. 
  23. ^ "Future of Space Transportation: S. Somanath" (PDF). 9 February 2016. 
  24. ^ Murthi, K.R. Sridhara (9 May 2009). "Space Debris Mitigation - Coordination and Implementation efforts in India" (PDF). Retrieved 22 November 2017. 
  25. ^ "ISRO's baby rocket to carry small satellites, likely to take off in 2019". The New Indian Express. Retrieved 2018-01-02. 

External links