Polar Satellite Launch Vehicle#Vehicle description

File:PSLV-C11 Strapon01.jpg

Studies by the PSLV Planning group under S Srinivasan to develop a vehicle capable of delivering a 600 kg payload to a 550 km sun-synchronous orbit from SHAR began in 1978.{{Cite book|title=Ready to Fire: How India and I survived the ISRO Spy case|publisher=Bloomsbury Publishing|year=2018|pages=203}}{{Cite book|title=From Fishing Hamlet to Red Planet|publisher=ISRO|pages=173}} Among 35 proposed configurations, four were picked; by November 1980, a vehicle configuration with two strap-ons on a core booster (S80) with 80 tonne solid propellant loading each, a liquid stage with 30 tonne propellant load (L30), and an upper stage called the Perigee-Apogee System (PAS) was being considered.{{cite news|url=https://books.google.com/books?id=IbbMj56ht8sC&pg=PA215|title=Indian ambitions in space go sky-high|date=22 January 1981|publisher=New Scientist|page=215|access-date=30 December 2018|archive-date=10 October 2022|archive-url=https://web.archive.org/web/20221010090941/https://books.google.com/books?id=IbbMj56ht8sC&pg=PA215|url-status=live}}{{cite book|title=A brief history of rocketry in ISRO|last1=Rao|first1=P.V. Monoranjan|last2=Radhakrishnan|first2=Paramaswaran|publisher=Orient Blackswan|year=2012 |isbn=978-8173717642|pages=215}}{{cite book|title=From fishing hamlet to red planet|publisher=Harpercollins|year=2015|isbn=978-9351776895|editor-last=Rao|editor-first=P.V. Manoranjan |chapter=2.6 PSLV: The workhorse of ISRO by N. Narayanamoorthy}}{{cite book|title=Reach For the Stars: The Evolution of India's Rocket Programme|last=Raj|first=Gopal|publisher=Viking|year=2000 |isbn=978-0670899500|chapter=8. PSLV: Achieving Operational Launch Capability|quote=About a year later, an important change was made, with the solid fourth stage being substituted by a liquid stage. This change was considered necessary since the accuracy with which the IRS satellites had to be put into orbit — within 15 km in terms of orbital height and within 0.1° of the desired orbital inclination — could not be achieved with a solid stage.}}

By 1981, confidence grew in remote sensing spacecraft development with the launch of Bhaskara-1, and the PSLV project objectives were upgraded to have the vehicle deliver a 1000 kg payload into a 900 km SSO. As technology transfer of Viking rocket engine firmed up, a new lighter configuration with the inclusion of a liquid powered stage was selected.{{Cite book|title=Ready To Fire: How India and I Survived the ISRO Spy Case|publisher=Bloomsbury Publishing|year=2018|pages=207–208}} Funding was approved in July 1982 for the finalized design, employing a single large S125 solid core as first stage with six 9 tonne strap-ons (S9) derived from the SLV-3 first stage, liquid fueled second stage (L33), and two solid upper stages (S7 and S2.) This configuration needed further improvement to meet the orbital injection accuracy requirements of IRS satellites, and hence, the solid terminal stage (S2) was replaced with a pressure fed liquid fueled stage (L1.8 or LUS) powered by twin engines derived from roll control engines of the first stage. Apart from increasing precision, liquid upper stage also absorbed any deviation in performance of solid third stage. The final configuration of PSLV-D1 to fly in 1993 was (6 × S9 + S125) + L37.5 + S7 + L2.

The inertial navigation systems are developed by ISRO Inertial Systems Unit (IISU) at Thiruvananthapuram. The liquid propulsion for the second and fourth stages of the PSLV as well as the Reaction control systems (RCS) are developed by the Liquid Propulsion Systems Centre (LPSC) at Valiamala near Thiruvananthapuram, kerala. The solid propellant motors are processed at Satish Dhawan Space Centre (SHAR) at Sriharikota, Andhra Pradesh, which also carries out launch operations. The aerodynamic characterization research was conducted at the National Aerospace Laboratories' 1.2m Trisonic Wind Tunnel Facility.{{Cite web |date=2022-06-06 |title=Bengaluru: 1.2m trisonic wind tunnel at National Aerospace Laboratories completes 55 years of service |url=https://www.aninews.in/news/national/general-news/bengaluru-12m-trisonic-wind-tunnel-at-national-aerospace-laboratories-completes-55-years-of-service20220606001500/ |access-date=2024-11-22 |website=ANI |language=en}}

The PSLV was first launched on 20 September 1993.{{Cite web |title=PSLV - ISRO |url=https://www.isro.gov.in/launchers/pslv |access-date=2022-03-09 |website=www.isro.gov.in |archive-date=9 February 2020 |archive-url=https://web.archive.org/web/20200209203227/https://www.isro.gov.in/launchers/pslv |url-status=live }} 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.{{cite web|title=India (Launchers)|url=http://claudelafleur.qc.ca/Indians-launchers.html|publisher=Spacecraft Encyclopedia|access-date=12 November 2014|archive-date=20 May 2016|archive-url=https://web.archive.org/web/20160520142430/http://claudelafleur.qc.ca/Indians-launchers.html|url-status=live}} After this initial setback, the PSLV successfully completed its second mission in 1994.{{cite web|title=PSLV (1)|url=http://space.skyrocket.de/doc_lau_det/pslv_1.htm|publisher=Gunter's Space Page|access-date=12 November 2014|archive-date=5 December 2020|archive-url=https://web.archive.org/web/20201205170455/https://space.skyrocket.de/doc_lau_det/pslv_1.htm|url-status=live}} The fourth launch of PSLV suffered a partial failure in 1997, leaving its payload in a lower than planned orbit. In November 2014, the PSLV had launched 34 times with no further failures.{{cite web|title=PSLV|url=http://space.skyrocket.de/doc_lau/pslv.htm|website=Gunter's Space Page|access-date=12 November 2014|archive-date=24 July 2011|archive-url=https://web.archive.org/web/20110724081813/http://space.skyrocket.de/doc_lau/pslv.htm|url-status=live}} (Although launch 41: August 2017 PSLV-C39 was unsuccessful.)

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.{{Cite web|url=http://www.isro.org/satellites/mars-orbiter-spacecraft.aspx|title=ISRO - Mars Orbiter Mission|access-date=2014-04-08|archive-date=27 October 2014|archive-url=https://web.archive.org/web/20141027123201/http://www.isro.org/satellites/mars-orbiter-spacecraft.aspx|url-status=live}}

In June 2018, the Union Cabinet approved {{INRconvert|6131|c|lk=on|year=2020}} for 30 operational flights of the PSLV scheduled to take place between 2019 and 2024.{{cite web|title=Government approves Rs 10,000-crore continuation programmes for PSLV, GSLV|url=https://economictimes.indiatimes.com/news/science/government-approves-rs-10000-crore-continuation-programmes-for-pslv-gslv/articleshow/64483323.cms|publisher=The Economic Times|date=7 June 2018|access-date=8 June 2018|archive-date=8 June 2018|archive-url=https://web.archive.org/web/20180608035934/https://economictimes.indiatimes.com/news/science/government-approves-rs-10000-crore-continuation-programmes-for-pslv-gslv/articleshow/64483323.cms|url-status=live}}

ISRO is working towards handing over the production and operation of PSLV to private industry through a joint venture.{{Cite web |title=Press Release - NSIL signs Contract with HAL (lead member of HAL-L&T consortium) for production of 05 nos of PSLV-XL |url=https://www.nsilindia.co.in/sites/default/files/Press%20Release-%20Contract%20signed%20for%20production%20of%2005%20nos%20PSLV-XL.pdf |archive-url=https://web.archive.org/web/20220909125437/https://www.nsilindia.co.in/sites/default/files/Press%20Release-%20Contract%20signed%20for%20production%20of%2005%20nos%20PSLV-XL.pdf |archive-date=9 September 2022}} On 16 August 2019, NewSpace India Limited issued an invitation to tender for manufacturing PSLV entirely by private industries.{{Cite news |last=D.s |first=Madhumathi |date=2019-08-16 |title=ISRO's business arm begins search for PSLV makers |language=en-IN |work=The Hindu |url=https://www.thehindu.com/news/national/new-isro-arm-begins-search-for-pslv-makers/article29112870.ece |access-date=2022-09-09 |issn=0971-751X |archive-date=9 September 2022 |archive-url=https://web.archive.org/web/20220909133320/https://www.thehindu.com/news/national/new-isro-arm-begins-search-for-pslv-makers/article29112870.ece |url-status=live }}{{Cite web |author=Chethan Kumar |date=Aug 27, 2021 |title=Adani, L&T among those in race for PSLV contract {{!}} India News - Times of India |url=https://timesofindia.indiatimes.com/india/adani-lt-in-race-for-deal-to-make-space-launch-vehicles/articleshow/85674630.cms |access-date=2022-09-09 |website=The Times of India |language=en |archive-date=9 September 2022 |archive-url=https://web.archive.org/web/20220909133322/https://timesofindia.indiatimes.com/india/adani-lt-in-race-for-deal-to-make-space-launch-vehicles/articleshow/85674630.cms |url-status=live }} On 5 September 2022, NewSpace India Limited signed a contract with Hindustan Aeronautics Limited and Larsen & Toubro led conglomerate for the production of five PSLV-XL launch vehicles after they won competitive bidding. Under this contract, they have to deliver their first PSLV-XL within 24 months and the remaining four vehicles every six months.{{Cite news |title=HAL-L&T to build five PSLV rockets, bags Rs 860 crore deal from NSIL for the project |work=The Economic Times |url=https://economictimes.indiatimes.com/industry/indl-goods/svs/engineering/hal-lt-to-build-five-pslv-rockets-bags-rs-860-crore-deal-from-nsil-for-the-project/articleshow/93980649.cms |access-date=2022-09-09 |archive-date=9 September 2022 |archive-url=https://web.archive.org/web/20220909133332/https://economictimes.indiatimes.com/industry/indl-goods/svs/engineering/hal-lt-to-build-five-pslv-rockets-bags-rs-860-crore-deal-from-nsil-for-the-project/articleshow/93980649.cms |url-status=live }}{{Cite news|date=2017-10-26|title=ISRO looks at JV for PSLV manufacture; launch to be privatized by 2020|publisher=Geospatial World|url=https://www.geospatialworld.net/blogs/isro-looks-jv-pslv-manufacture-launch-privatized-2020/|access-date=2017-10-26|archive-date=16 November 2017|archive-url=https://web.archive.org/web/20171116011358/https://www.geospatialworld.net/blogs/isro-looks-jv-pslv-manufacture-launch-privatized-2020/|url-status=live}}{{Cite web |author=Chethan Kumar |date=Apr 9, 2022 |title=Hal-l&t Wins Over 824-cr Contract For Making 5 Pslvs {{!}} India News - Times of India |url=https://timesofindia.indiatimes.com/india/hal-lt-wins-over-824-cr-contract-for-making-5-pslvs/articleshow/90736339.cms |access-date=2022-09-09 |website=The Times of India |language=en |archive-date=9 September 2022 |archive-url=https://web.archive.org/web/20220909133320/https://timesofindia.indiatimes.com/india/hal-lt-wins-over-824-cr-contract-for-making-5-pslvs/articleshow/90736339.cms |url-status=live }}

The PSLV has four stages, using solid and liquid propulsion systems alternately.

File:PSLV-C44 Integrated upto First Stage inside Mobile Service Tower.jpg first stage inside Mobile Service Tower]]

The first stage, one of the largest solid rocket boosters in the world, carries {{cvt|138|MT}} of hydroxyl-terminated polybutadiene-bound (HTPB) propellant and develops a maximum thrust of about {{cvt|4800|kN}}. The {{cvt|2.8|m}} diameter motor case is made of maraging steel and has an empty mass of {{cvt|30200|kg}}.{{cite web|url=http://www.spaceflight101.com/pslv-launch-vehicle-information.html|title=PSLV Launch Vehicle Information|publisher=Spaceflight 101|access-date=February 20, 2015|archive-url=https://web.archive.org/web/20150924115759/http://www.spaceflight101.com/pslv-launch-vehicle-information.html|archive-date=24 September 2015|url-status=dead}}

Pitch and yaw control during first stage flight is provided by the Secondary Injection Thrust Vector Control (SITVC) System, which injects an aqueous solution of strontium perchlorate into the S139 exhaust divergent from a ring of 24 injection ports to produce asymmetric thrust. The solution is stored in two cylindrical aluminium tanks strapped to the core solid rocket motor and pressurised with nitrogen. Underneath these two SITVC tanks, Roll Control Thruster (RCT) modules with small bi-propellant (MMH/MON) liquid engine are also attached.{{Cite web|date=10 October 1993|title=Current Science (Volume 65 - Issue 07) PSLV-D1|url=https://www.currentscience.ac.in/Downloads/article_id_065_07_0522_0528_0.pdf|url-status=live|archive-url=https://web.archive.org/web/20200806072408/https://www.currentscience.ac.in/Downloads/article_id_065_07_0522_0528_0.pdf|archive-date=6 August 2020|access-date=20 December 2019}}

On the PSLV-G 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 {{cvt|9|MT}} or {{cvt|12|MT}} (for PSLV-XL configuration) propellant and produce {{cvt|510|kN}} and {{cvt|719|kN}} thrust respectively. Two strap-on boosters are equipped with SITVC for additional attitude control. The PSLV-CA uses no strap-on boosters.

First stage separation is aided by four pairs of retro-rockets installed on inter-stage (1/2L). During staging, these eight rockets help push away the spent stage away from second stage.{{cite web|url=https://www.isro.gov.in/sites/default/files/flipping_book/PSLV-C1/files/assets/basic-html/page-3.html|title=PSLV-C1|website=isro.gov.in|access-date=22 February 2020|archive-date=6 August 2020|archive-url=https://web.archive.org/web/20200806063834/https://www.isro.gov.in/sites/default/files/flipping_book/PSLV-C1/files/assets/basic-html/page-3.html|url-status=live}}

File:PSLV C50 second stage with Vikas engine.jpg]]

The second stage is powered by a single Vikas engine and carries {{cvt|41.5|MT}} of Earth store-able liquid propellant{{spaced ndash}}unsymmetrical dimethylhydrazine (UDMH) as fuel and nitrogen tetroxide (N₂O₄) as oxidiser in two tanks separated by a common bulkhead. It generates a maximum thrust of {{cvt|800|kN}}. The engine is gimbaled (±4°) in two planes to provide pitch and yaw control by two actuators, while roll control is provided by a Hot gas Reaction Control Motor (HRCM) that ejects hot gases diverted from gas generator of Vikas engine.{{cite web|url=https://www.isro.gov.in/sites/default/files/flipping_book/10-Space_India-1_1990/files/assets/basic-html/page-7.html|title=Space India 1/1990|website=isro.gov.in|access-date=22 February 2020|archive-date=6 August 2020|archive-url=https://web.archive.org/web/20200806054903/https://www.isro.gov.in/sites/default/files/flipping_book/10-Space_India-1_1990/files/assets/basic-html/page-7.html|url-status=live}}

On inter-stage (1/2U) of PS2, there are two pairs of ullage rockets to maintain positive acceleration during PS1/PS2 staging and also two pairs of retro-rockets to help push away spent stage during PS2/PS3 staging.

Second stage also carries some quantity of water in a toroidal tank at its bottom.{{cite web|url=https://www.isro.gov.in/sites/default/files/flipping_book/PSLV-C8/files/assets/common/downloads/publication.pdf|url-status=dead|title=PSLV C8 / AGILE brochure|access-date=23 February 2020|archive-date=23 February 2020|archive-url=https://web.archive.org/web/20200223011646/https://www.isro.gov.in/sites/default/files/flipping_book/PSLV-C8/files/assets/common/downloads/publication.pdf}} Water spray is used to cool hot gases from Vikas' gas generator to about 600 °C before entering turbopump. Propellant and water tanks of second stage are pressurized by Helium.{{Cite journal |title=Development & qualification of Titanium Alloy High-Pressure Gas Bottles for PSLV second Stage |url=http://adsabs.harvard.edu/full/1999ESASP.430..559T |url-status=live |access-date=2021-04-07 |journal=Cooperation in Space |bibcode=1999ESASP.430..559T |last1=Thomas |first1=George |last2=Pant |first2=Bhanu |last3=Ganesan |first3=R. |last4=Singh |first4=S. K. |last5=Sinha |first5=P. P. |year=1999 |volume=430 |page=559 |archive-date=11 November 2020 |archive-url=https://web.archive.org/web/20201111223537/http://adsabs.harvard.edu/full/1999ESASP.430..559T }}{{cite book |title=Envisioning An Empowered nation|isbn=978-0070531543|page=40|last=Sivathanu Pillai|first=A.|year=2004|publisher=Tata McGraw-Hill Publishing Company }}{{Cite web|date=April 1990|title=Space India Jan-Mar 1990|url=https://www.isro.gov.in/sites/default/files/flipping_book/10-Space_India-1_1990/files/assets/common/downloads/publication.pdf|url-status=live|archive-url=https://web.archive.org/web/20210407195425/https://www.isro.gov.in/sites/default/files/flipping_book/10-Space_India-1_1990/files/assets/common/downloads/publication.pdf|archive-date=7 April 2021|access-date=8 April 2021}}

File:PSLV C45 EMISAT campaign 09.jpg]]

The third stage uses {{cvt|7.6|MT}} of HTPB solid propellant and produces a maximum thrust of {{cvt|250|kN}}. Its burn duration is 113.5 seconds. It has a Kevlar-polyamide fibre case and a submerged nozzle equipped with a flex-bearing-seal gimbaled nozzle with ±2° thrust vector for pitch and yaw control. Roll control is provided by the fourth stage reaction control system (RCS) during thrust phase as well as during combined-coasting phase under which burnt-out PS3 remains attached to PS4.{{Cite web |date=25 September 2015 |title=PSLV-C25: the vehicle that launched the Indian Mars Orbiter |url=https://www.currentscience.ac.in/Volumes/109/06/1055.pdf |archive-url=https://web.archive.org/web/20151224184646/http://www.currentscience.ac.in/Volumes/109/06/1055.pdf |archive-date=24 December 2015 |website=Current Science}}

The fourth stage is powered by regeneratively cooled twin engines,{{cite web|url=http://asaco.in/aerospace/sub-systems-for-aerospace/|title=ASACO sub-systems for space.|archive-url=https://web.archive.org/web/20171211095555/http://asaco.in/aerospace/sub-systems-for-aerospace/|archive-date=11 December 2017|url-status=live|access-date=16 October 2018}} burning monomethylhydrazine (MMH) and mixed oxides of nitrogen (MON). Each pressure fed engine generates {{cvt|7.4|kN}} thrust and is gimbaled (±3°) to provide pitch, yaw and roll control during powered flight. Coast phase attitude control is provided by six 50N RCS thrusters.{{cite journal|last1=Ramakrishnan|first1=S.|last2=Somanath|first2=S.|last3=Balakrishnan|first3=S. S.|date=2002-01-01|title=Multi-Orbit Mission by PSLV-C3 and Future Launch Opportunities|journal=Iaf Abstracts|pages=936|bibcode=2002iaf..confE.936R}} The stage is pressurized by helium{{Cite web|title=Latest Volume14-Issue21 News, Photos, Latest News Headlines about Volume14-Issue21|url=https://frontline.thehindu.com/magazine/issue/vol14-21/|access-date=2021-04-07|website=Frontline|language=en|archive-date=7 May 2021|archive-url=https://web.archive.org/web/20210507005441/https://frontline.thehindu.com/magazine/issue/vol14-21/|url-status=live}} and carries {{cvt|1600|kg}} to {{cvt|2500|kg}} of propellant depending on the mission requirements. PS4 has three variants L1.6, L2.0 and L2.5 based on propellant tank capacity.{{Cite web |title=Signatures, Newsletter of the Indian Society of Remote Sensing – Ahmedabad Chapter. Volume: 24, No.2, April- June 2012 |url=https://www.sac.gov.in/SAC_Industry_Portal/publication/newsletter/Signatures_RISAT.pdf |archive-url=https://web.archive.org/web/20211221142837/https://www.sac.gov.in/SAC_Industry_Portal/publication/newsletter/Signatures_RISAT.pdf |archive-date=21 December 2021 |access-date=31 July 2023 |quote=The fourth stage has three variants designated as L1.6, L2.0 and L2.5 based on the propellant loading capacity of 1.6t, 2t and 2.5t respectively required for a particular mission.}}

On PSLV-C29/TeLEOS-1 mission, the fourth stage demonstrated re-ignition capability for the first time which was used in many subsequent flights to deploy payloads in multiple orbits on a single campaign.{{cite web|title=ISRO Successfully Tests Multiple Burn Fuel Engine During Launch of Six Singaporean Satellites|url=http://www.newindianexpress.com/states/andhra_pradesh/ISRO-Successfully-Tests-Multiple-Burn-Fuel-Engine-During-Launch-of-Six-Singaporean-Satellites/2015/12/16/article3180961.ece|access-date=16 December 2015|archive-date=3 May 2016|archive-url=https://web.archive.org/web/20160503044453/http://www.newindianexpress.com/states/andhra_pradesh/ISRO-Successfully-Tests-Multiple-Burn-Fuel-Engine-During-Launch-of-Six-Singaporean-Satellites/2015/12/16/article3180961.ece|url-status=dead}}

As a space debris mitigation measure, PSLV fourth stage gets passivated by venting pressurant and propellant vapour after achieving main mission objectives. Such passivation prevents any unintentional fragmentation or explosion due to stored internal energy.{{Cite journal|last1=Adimurthy|first1=V.|last2=Ganeshan|first2=A.S.|date=February 2006|title=Space debris mitigation measures in India|url=https://linkinghub.elsevier.com/retrieve/pii/S0094576505002961|journal=Acta Astronautica|language=en|volume=58|issue=3|pages=168–174|doi=10.1016/j.actaastro.2005.09.002|bibcode=2006AcAau..58..168A|access-date=26 December 2021|archive-date=12 April 2022|archive-url=https://web.archive.org/web/20220412004038/https://linkinghub.elsevier.com/retrieve/pii/S0094576505002961|url-status=live}}{{Cite journal|last=Bonnal|first=C|date=2007-06-01|title=Design and operational practices for the passivation of spacecraft and launchers at the end of life|url=http://journals.sagepub.com/doi/10.1243/09544100JAERO231|journal=Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering|language=en|volume=221|issue=6|pages=925–931|doi=10.1243/09544100JAERO231|s2cid=110656798|issn=0954-4100}}{{Cite web|title=Indian Presentation to the 47th Session of Scientific and Technical Subcommittee of United Nations Committee on the Peaceful Uses of Outer Space Agenda 8 'Space Debris Activities in India'|url=https://www.unoosa.org/pdf/pres/stsc2010/tech-33.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://www.unoosa.org/pdf/pres/stsc2010/tech-33.pdf |archive-date=2022-10-09|url-status=live}}

The niobium alloy nozzle used on twin engines of fourth stage is expected to be replaced by lighter, silicon carbide coated carbon–carbon nozzle divergent. The new nozzle was hot tested at facilities of IPRC, Mahendragiri in March and April 2024. This substitution should increase payload capacity of PSLV by {{Convert|15|kg|lb}}.{{Cite web |title=ISRO Develops Lightweight Carbon-Carbon Nozzle for Rocket Engines, Enhancing Payload Capacity |url=https://www.isro.gov.in/ISRO_Develops_Lightweight_Carbon_Carbon_Nozzle_for_Rocket_Engines.html |archive-url=https://web.archive.org/web/20240419183918/https://www.isro.gov.in/ISRO_Develops_Lightweight_Carbon_Carbon_Nozzle_for_Rocket_Engines.html |archive-date=19 April 2024 |access-date=2024-04-21 |website=www.isro.gov.in}} ISRO also replaced imported Columbium materials in the engine nozzle divergent with Stellite, which resulted in cost savings of 90%. The newly modified engines were tested at IPRC in April 2025.{{Cite web |title=ISRO Successfully qualifies fourth stage engine of PSLV with Satellite Nozzle Divergent |url=https://www.isro.gov.in/ISRO_Successfully_qualifies_fourth_stage_engine_of_PSLV_with_Satellite_Nozzle_Divergent.html |archive-url=http://web.archive.org/web/20250418060419/https://www.isro.gov.in/ISRO_Successfully_qualifies_fourth_stage_engine_of_PSLV_with_Satellite_Nozzle_Divergent.html |archive-date=2025-04-18 |access-date=2025-04-18 |website=www.isro.gov.in |language=en}}

ISRO successfully completed 665-second hot test of 3D printed PS4 engine, produced by Wipro 3D through selective laser melting. A total of 19 weld joints were eliminated through this process while engine's 14 components were reduced to one piece. It saved 60% of the production time and drastically decreased the amount of raw materials used per engine, from 565 kg to 13.7 kg of metal powder.{{Cite news |date=2024-05-11 |title=With 3D-printed rocket engine, Isro adds another feather to cap |url=https://timesofindia.indiatimes.com/india/with-3d-printed-rocket-engine-isro-adds-another-feather-to-cap/articleshow/110019883.cms |access-date=2024-05-13 |work=The Times of India |issn=0971-8257}}

{{Main|PSLV Orbital Experiment Module}}

PS4 has carried hosted payloads like AAM on PSLV-C8, Rubin 9.1/Rubin 9.2 on PSLV-C14{{cite web|url=https://www.isro.gov.in/sites/default/files/flipping_book/PSLV-C14/files/assets/common/downloads/publication.pdf|url-status=dead|title=PSLV C14/Oceansat-2 brochure|access-date=23 February 2020|archive-date=6 August 2020|archive-url=https://web.archive.org/web/20200806094152/https://www.isro.gov.in/sites/default/files/flipping_book/PSLV-C14/files/assets/common/downloads/publication.pdf}} and mRESINS on PSLV-C21.{{cite web |url=https://www.dos.gov.in/sites/default/files/flipping_book/Space%20India%20July%2012-Aug%2013/files/assets/common/downloads/Space%20India%20July%2012-Aug%2013.pdf |url-status=dead |title=Space-India July 2012 to August 2013 |access-date=23 February 2020 |archive-date=6 August 2020 |archive-url=https://web.archive.org/web/20200806152719/https://www.dos.gov.in/sites/default/files/flipping_book/Space%20India%20July%2012-Aug%2013/files/assets/common/downloads/Space%20India%20July%2012-Aug%2013.pdf }} But now, PS4 is being augmented to serve as a long duration orbital platform after completion of primary mission. PS4 Orbital Platform (PS4-OP) will have its own power supply, telemetry package, data storage and attitude control for hosted payloads.{{cite web|url=http://www.unoosa.org/documents/pdf/copuos/stsc/2019/tech-55E.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.unoosa.org/documents/pdf/copuos/stsc/2019/tech-55E.pdf |archive-date=2022-10-09 |url-status=live|title=Opportunities for science experiments in the fourth stage of India's PSLV|date=21 February 2019}}{{cite web|url=https://www.isro.gov.in/sites/default/files/orbital_platform-_ao.pdf|url-status=dead|title=Announcement of Opportunity (AO) for Orbital platform: an avenue for in-orbit scientific experiments|date=15 June 2019|access-date=23 February 2020|archive-date=6 August 2020|archive-url=https://web.archive.org/web/20200806072033/https://www.isro.gov.in/sites/default/files/orbital_platform-_ao.pdf}}{{cite news|url=https://timesofindia.indiatimes.com/india/2-days-after-space-station-news-isro-calls-for-docking-experiments-on-pslv-stage-4/articleshow/69800354.cms|title=2 days after Space Station news, Isro calls for "docking experiments" on PSLV stage-4|first=Chethan|last=Kumar|work=The Times of India|date=15 June 2019 |access-date=23 February 2020|archive-date=24 August 2019|archive-url=https://web.archive.org/web/20190824073052/https://timesofindia.indiatimes.com/india/2-days-after-space-station-news-isro-calls-for-docking-experiments-on-pslv-stage-4/articleshow/69800354.cms|url-status=live}}

On PSLV-C37 and PSLV-C38 campaigns,{{Cite web |title=In-situ observations of rocket burn induced modulations of the top side ionosphere using the IDEA payload on-board the unique orbiting experimental platform (PS4) of the Indian Polar Orbiting Satellite Launch Vehicle mission - ISRO |url=https://www.isro.gov.in/situ-observations-of-rocket-burn-induced-modulations-of-top-side-ionosphere-using-idea-payload-board |access-date=2022-06-27 |website=www.isro.gov.in |language=en |archive-date=21 September 2022 |archive-url=https://web.archive.org/web/20220921000216/https://www.isro.gov.in/situ-observations-of-rocket-burn-induced-modulations-of-top-side-ionosphere-using-idea-payload-board |url-status=live }} as a demonstration PS4 was kept operational and monitored for over ten orbits after delivering spacecraft.{{cite web |url=https://www.isro.gov.in/sites/default/files/article-files/node/9805/annualreport2017-18.pdf|title=Department of Space Annual Report 2017-18|url-status=live|archive-url=https://web.archive.org/web/20180213093132/https://www.isro.gov.in/sites/default/files/article-files/node/9805/annualreport2017-18.pdf|archive-date=13 February 2018}}{{cite web|url=https://timesofindia.indiatimes.com/india/in-a-first-isro-will-make-dead-rocket-stage-alive-in-space-for-experiments/articleshow/67067817.cms|title=In a first, ISRO will make dead rocket stage "alive" in space for experiments|first=Surendra|last=Singh|work=The Times of India|date=16 December 2018|access-date=23 February 2020|archive-date=8 November 2020|archive-url=https://web.archive.org/web/20201108132514/https://timesofindia.indiatimes.com/india/in-a-first-isro-will-make-dead-rocket-stage-alive-in-space-for-experiments/articleshow/67067817.cms|url-status=live}}{{cite web|url=https://www.deccanchronicle.com/science/science/200617/isro-to-lower-rockets-altitude.html|title=Isro to lower rocket's altitude|last=rajasekhar|first=pathri|publisher=Deccan Chronicle|date=2017-06-20|access-date=23 February 2020|archive-date=6 August 2020|archive-url=https://web.archive.org/web/20200806095054/https://www.deccanchronicle.com/science/science/200617/isro-to-lower-rockets-altitude.html|url-status=live}}

PSLV-C44 was the first campaign where PS4 functioned as independent orbital platform for short duration as there was no on-board power generation capacity.{{cite news|last=Rajwi|first=Tiki|url=https://www.thehindu.com/news/national/kerala/pslv-lift-off-with-added-features/article25981654.ece|title=PSLV lift-off with added features|date=2019-01-12|newspaper=The Hindu|issn=0971-751X|access-date=23 February 2020|archive-date=6 August 2020|archive-url=https://web.archive.org/web/20200806161530/https://www.thehindu.com/news/national/kerala/pslv-lift-off-with-added-features/article25981654.ece|url-status=live}} It carried KalamSAT-V2 as a fixed payload, a 1U CubeSat by Space Kidz India based on Interorbital Systems kit.{{cite web|title=PSLV-C44 - ISRO|url=https://www.isro.gov.in/launcher/pslv-c44|access-date=26 June 2020|website=isro.gov.in|archive-date=17 January 2019|archive-url=https://web.archive.org/web/20190117013408/https://www.isro.gov.in/launcher/pslv-c44|url-status=dead}}{{cite tweet|number=1088526772109422592|user=interorbital|title=Congratulations to ISRO and SpaceKidzIndia on getting their CubeSat into orbit! The students modified their IOS CubeSat kit, complete w/ their own experiments!|author=Interorbital Systems|date=25 January 2019}}

On PSLV-C45 campaign, the fourth stage had its own power generation capability as it was augmented with an array of fixed solar cells around PS4 propellant tank.{{cite web|url=https://spaceflightnow.com/2019/04/01/indian-military-satellite-20-more-planet-imaging-cubesats-aboard-successful-pslv-launch/|title=Indian military satellite, 20 more Planet imaging CubeSats launched by PSLV|last=Clark|first=Stephen|publisher=Spaceflight Now|access-date=2020-02-23|archive-date=6 April 2019|archive-url=https://web.archive.org/web/20190406042135/https://spaceflightnow.com/2019/04/01/indian-military-satellite-20-more-planet-imaging-cubesats-aboard-successful-pslv-launch/|url-status=live}} The three payloads hosted on PS4-OP were the Advanced Retarding Potential Analyzer for Ionospheric Studies (ARIS 101F) by IIST,{{cite web|url=https://www.iist.ac.in/avionics/sudharshan.kaarthik|title=Department of Avionics, R. Sudharshan Kaarthik, Ph.D (Assistant Professor)|access-date=23 February 2020|archive-date=13 February 2020|archive-url=https://web.archive.org/web/20200213005932/https://www.iist.ac.in/avionics/sudharshan.kaarthik|url-status=live}} an experimental AIS payload by ISRO, and AISAT by Satellize.{{cite web|url=https://satellize.com/index.php/exseed-sat-2/|title=Exseed Sat-2|publisher=Satellize|access-date=23 February 2020|archive-date=23 February 2020|archive-url=https://web.archive.org/web/20200223011624/https://satellize.com/index.php/exseed-sat-2/|url-status=live}} To function as orbital platform, fourth stage was put in spin-stabilized mode using its RCS thrusters.{{Cite web |date=16 June 2021 |title=Opportunity for Scientific Experiments on PSLV Upper Stage Orbital Platform |url=https://www.unoosa.org/documents/pdf/psa/hsti/Hyper-Microgravity_Webinar2021/Hyper-Microgravity_Webinar2021/9_RegionalActivities/R._Senan_Hypermicrogravity_ISRO.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://www.unoosa.org/documents/pdf/psa/hsti/Hyper-Microgravity_Webinar2021/Hyper-Microgravity_Webinar2021/9_RegionalActivities/R._Senan_Hypermicrogravity_ISRO.pdf |archive-date=2022-10-09 |url-status=live}}

On the PSLV-C53 campaign, the PS4-OP is referred to as the PSLV Orbital Experimental Module (POEM), and it hosted six payloads. POEM was the first PSLV fourth stage based orbital platform to be actively stabilised using Helium based cold gas thrusters after the primary mission and stage passivization.{{Cite web |last=Kumar |first=Chethan |date=June 25, 2012 |title=Bengaluru's Digantara, Hyderabad startup Dhruva become first to get IN-SPACe authorisation |url=https://timesofindia.indiatimes.com/india/bengaluru-digantara-hyderabad-startup-dhruva-become-first-to-get-in-space-authorisation/articleshow/92460375.cms |url-status=live |archive-url=https://web.archive.org/web/20220625153537/https://timesofindia.indiatimes.com/india/bengaluru-digantara-hyderabad-startup-dhruva-become-first-to-get-in-space-authorisation/articleshow/92460375.cms |archive-date=2022-06-25 |access-date=2022-06-26 |website=The Times of India |language=en}}{{Cite web |title=PSLV-C53/DS-EO mission |url=https://www.isro.gov.in/sites/default/files/article-files/pslv-c53-ds-eo-mission/pslv-c53-ds-eo-mission-brochure-english/brochure_pslv_c53-ds-eo_mission_english.pdf |archive-url=https://web.archive.org/web/20220705162540/https://www.isro.gov.in/sites/default/files/article-files/pslv-c53-ds-eo-mission/pslv-c53-ds-eo-mission-brochure-english/brochure_pslv_c53-ds-eo_mission_english.pdf |archive-date=5 July 2022}}{{Cite web |title=పీఎస్‌ఎల్‌వీ-సి53లో నూతన సాంకేతికత |url=https://www.eenadu.net/telugu-news/related-stories/general/2505/122117906 |url-status=live |archive-url=https://web.archive.org/web/20220706195945/https://www.eenadu.net/telugu-news/related-stories/general/2505/122117906 |archive-date=2022-07-06 |access-date=2022-07-06 |website=EENADU |language=te}}{{Cite web |author=News9 Staff |date=2022-09-08 |title=Har Ghar Tiranga happened in Antriksh. ISRO did hoist the Indian flag in Space! |url=https://www.news9live.com/india/har-ghar-tiranga-happened-in-antriksh-isro-did-hoist-the-indian-flag-in-space-194691 |access-date=2022-09-09 |website=NEWS9LIVE |language=en |archive-date=9 September 2022 |archive-url=https://web.archive.org/web/20220909095750/https://www.news9live.com/india/har-ghar-tiranga-happened-in-antriksh-isro-did-hoist-the-indian-flag-in-space-194691 |url-status=live }}

The Reusable Launch Vehicle Technology Demonstration program is an prototype spaceplane project currently being processed by ISRO. It is planned to use a GSLV, modified by replacing it's Cryogenic Upper Stage(CUS) with the PS-4 as the RLV would not required the excess thrust created by the CUS.{{Cite news |title=RLV re-entry mission to use GSLV with PSLV last stage; landing gear to change & more |url=https://timesofindia.indiatimes.com/india/rlv-re-entry-mission-to-use-gslv-with-pslv-last-stage-landing-gear-to-change-more/articleshow/111267553.cms |access-date=2024-06-26 |work=The Times of India |issn=0971-8257}}{{Cite web |title=MSN |url=https://www.msn.com/en-in/news/other/rlv-re-entry-mission-to-use-gslv-with-pslv-last-stage-landing-gear-to-change-more/ar-BB1oSNaF |access-date=2024-06-26 |website=www.msn.com}}

File:PSLV heat shield at HAL museum, Bengaluru (Ank Kumar) 01.jpg, Bengaluru]]

Payload fairing of PSLV, also referred as its "Heatshield" consists of a conical upper section with spherical nose-cap, a cylindrical middle section and a lower boat-tail section. Weighing {{Convert|1,182|kg|lb}}, it has 3.2 meter diameter and 8.3 meter height.{{cite web|url=https://www.hou.usra.edu/meetings/orbitaldebris2019/orbital2019paper/pdf/6159.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://www.hou.usra.edu/meetings/orbitaldebris2019/orbital2019paper/pdf/6159.pdf |archive-date=2022-10-09 |url-status=live|title=IRNSS-1H/PSLV-C39 Orbit Evolution and Re-entry Analysis|last=Singh|first=Satyendra|date=11 December 2019 |access-date=19 December 2019}} It has Isogrid construction and is made out of 7075 aluminum alloy with a 3 mm thick steel nose-cap.{{cite web|last1=Ramamurti|first1=V|last2=Rajarajan|first2=S|last3=Rao|first3=G Venkateswara|date=Oct 2001|title=Dynamic studies of a typical payload fairing for different boat tail configurations|url=http://nopr.niscair.res.in/bitstream/123456789/24368/1/IJEMS%208%285%29%20247-254.pdf|url-status=live|archive-url=https://web.archive.org/web/20200806085530/http://nopr.niscair.res.in/bitstream/123456789/24368/1/IJEMS%208%285%29%20247-254.pdf|archive-date=6 August 2020}}{{cite AV media|url=http://mmcr.iisc.ernet.in:8008/cgi-bin/nwayfiles.py?folder=Any+folder&date=2015-08-21&title=Any+title&presenter=Any+presenter&button=Search|title=Indigenous Development of Materials for Space Programme|date=21 August 2015|time=20 minutes 40 seconds|access-date=8 January 2020|archive-date=3 December 2020|archive-url=https://web.archive.org/web/20201203100310/http://mmcr.iisc.ernet.in:8008/cgi-bin/nwayfiles.py?folder=Any%2Bfolder&date=2015-08-21&title=Any%2Btitle&presenter=Any%2Bpresenter&button=Search|url-status=live}} The two halves of fairing are separated using a pyrotechnic device based jettisoning system consisting of horizontal and lateral separation mechanisms.{{Cite web|last1=Chakraborty|first1=D|last2=Vasantha|first2=S|title=Aerodynamic simulation of heatshield separation on ground.|url=https://www.aero.iitb.ac.in/~debasis/assets/int/JP-int-2.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://www.aero.iitb.ac.in/~debasis/assets/int/JP-int-2.pdf |archive-date=2022-10-09|url-status=live}} To protect the spacecraft from damage due to excessive acoustic loads during launch, the heatshield interior is lined with acoustic blankets.

{{Clear}}

ISRO has envisaged a number of variants of PSLV to cater to different mission requirements. There are currently two operational versions of the PSLV — the core-alone (PSLV-CA) without strap-on motors, and the (PSLV-XL) version, with six extended length (XL) strap-on motors carrying 12 tonnes of HTPB based propellant each.{{cite news|url=http://www.thehindu.com/sci-tech/science/article2230282.ece|title=The PSLV is a proud symbol of ISRO's self-reliance|location=Chennai, India|work=The Hindu|first=T.S.|last=Subramanian|date=15 July 2011|access-date=16 July 2011|archive-date=26 October 2012|archive-url=https://web.archive.org/web/20121026015701/http://www.thehindu.com/sci-tech/science/article2230282.ece|url-status=live}} These configurations provide wide variations in payload capabilities up to {{cvt|3800|kg}} in LEO and {{cvt|1800|kg}} in sun-synchronous orbit.

The standard or "Generic" version of the PSLV, PSLV-G had four stages using solid and liquid propulsion systems alternately and six strap-on motors (PSOM or S9) with 9 tonne propellant loading. It had capability to launch {{cvt|1678|kg}} to {{cvt|622|km}} into sun-synchronous orbit. PSLV-C35 was the last operational launch of PSLV-G before its discontinuation.{{cite news|url=https://www.hindustantimes.com/india-news/pslv-c34-isro-s-biggest-launch-event-as-it-unfolded/story-60VI3nZjesqzhjWVUifj4H.html|title=Where India reaches for the stars: Inside ISRO's Sriharikota Centre|date=2016-06-22|publisher=Hindustan Times|access-date=2018-09-15|quote=Today, the PSLV is available in three configurations — the generic vehicle with six strap-ons, which is the earlier edition of PSLV (which will be discontinued soon)|archive-date=15 September 2018|archive-url=https://web.archive.org/web/20180915230041/https://www.hindustantimes.com/india-news/pslv-c34-isro-s-biggest-launch-event-as-it-unfolded/story-60VI3nZjesqzhjWVUifj4H.html|url-status=live}}{{cite web|url=https://www.isro.gov.in/sites/default/files/article-files/node/7064/outcomebudget2016-2017.pdf|url-status=dead|title=Outcome Budget 2016–2017|publisher=Government of India, Department of Space|date=2016|access-date=15 September 2018|quote=Currently, two versions of PSLV are operational, namely PSLV-XL (with six extended version of Strap-on motors) and the PSLV Core-alone (without Strap-on motors).|archive-date=25 June 2017|archive-url=https://web.archive.org/web/20170625163259/http://isro.gov.in/sites/default/files/article-files/node/7064/outcomebudget2016-2017.pdf}}{{cite book|title=From Fishing Hamlet to Red Planet: India's Space Journey|publisher=Harpercollins|year=2015|isbn=978-9351776895|chapter=2.6 PSLV: The workhorse of ISRO by N. Narayanamoorthy}}

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 but two SITVC tanks with Roll Control Thruster modules are still attached to the side of the first stage with addition of two cylindrical aerodynamic stabilizers.{{cite web |url=http://www.spacelaunchreport.com/pslv.html |title=PSLV Datasheet |access-date=27 September 2009 |archive-date=28 July 2020 |archive-url=https://web.archive.org/web/20200728073632/http://www.spacelaunchreport.com/pslv.html |url-status=usurped }} The fourth stage of the CA variant has {{cvt|400|kg}} less propellant when compared to its standard version. It currently has capability to launch {{cvt|1100|kg}} to {{cvt|622|km}} Sun-synchronous orbit.{{cite web|url=http://www.earth2orbit.com/pdf/PSLV.PDF|title=India's PSLV|date=15 March 2009|website=www.earth2orbit.com |archive-url=https://web.archive.org/web/20110710163553/http://www.earth2orbit.com/pdf/PSLV.PDF|archive-date=10 July 2011|url-status=dead}}

PSLV-XL is the upgraded version of Polar Satellite Launch Vehicle in its standard configuration boosted by more powerful, stretched strap-on boosters with 12 tonne propellant load. Weighing {{cvt|320|MT}} at lift-off, the vehicle uses larger strap-on motors (PSOM-XL or S12) to achieve higher payload capability.[http://isro.org/pressrelease/Oct22_2008.htm PSLV-C11 Successfully Launches Chandrayaan-1] {{webarchive|url=https://web.archive.org/web/20081025031443/http://www.isro.org/pressrelease/Oct22_2008.htm|date=25 October 2008}} On 29 December 2005, ISRO successfully tested the improved version of strap-on booster for the PSLV.{{cite web|url=http://www.isro.org/newsletters/spaceindia/oct2005mar2006/Newsolid.htm|title=New Solid Propellant Motor to Increase PSLV Capability|publisher=ISRO|archive-url=https://web.archive.org/web/20090217222352/http://isro.org/newsletters/spaceindia/oct2005mar2006/Newsolid.htm|archive-date=17 February 2009|url-status=live|access-date=27 April 2007}} The first use of PSLV-XL was the launch of Chandrayaan-1 by PSLV-C11. The payload capability for this variant is {{cvt|1800|kg}} to Sun-synchronous orbit.

PSLV-DL variant has only two strap-on boosters with 12 tonne propellant load on them. PSLV-C44 on 24 January 2019 was the first flight to use PSLV-DL variant of Polar Satellite Launch Vehicle.{{cite news|last1=Rajwi|first1=Tiki|title=SLV-C44 to lift-off with added features|url=https://www.thehindu.com/sci-tech/science/pslv-c44-to-lift-off-with-added-features/article25972663.ece|access-date=11 January 2019|archive-date=11 January 2019|archive-url=https://web.archive.org/web/20190111210842/https://www.thehindu.com/sci-tech/science/pslv-c44-to-lift-off-with-added-features/article25972663.ece|url-status=live}}{{cite news|url=https://www.thehindu.com/news/national/kerala/pslv-lift-off-with-added-features/article25981654.ece|title=PSLV lift-off with added features|last=Rajwi|first=Tiki|date=2019-01-12|newspaper=The Hindu|access-date=2019-01-12|issn=0971-751X|archive-date=6 August 2020|archive-url=https://web.archive.org/web/20200806161530/https://www.thehindu.com/news/national/kerala/pslv-lift-off-with-added-features/article25981654.ece|url-status=live}} It is capable of launching {{Cvt|1257|kg|lb}} to {{Cvt|600|km|mi}} Sun-synchronous orbit.

File:PSLV C45 EMISAT campaign 22.jpg lift off]]

PSLV-QL variant has four ground-lit strap-on boosters, each with 12 tonnes of propellant. PSLV-C45 on 1 April 2019 was the first flight of PSLV-QL.{{cite web|url=https://www.isro.gov.in/pslv-c45-emisat-mission/launch-kit|title=Launch Kit C45|publisher=ISRO|access-date=23 March 2019|archive-date=24 March 2019|archive-url=https://web.archive.org/web/20190324134458/https://www.isro.gov.in/pslv-c45-emisat-mission/launch-kit|url-status=live}} It has the capacity to launch {{Cvt|1523|kg|lb}} to {{Cvt|600|km|mi}} Sun-synchronous orbit.{{cite web|title=The Polar Satellite Launch Vehicle (PSLV)|url=https://www.vssc.gov.in/PSLV.html|archive-url=https://web.archive.org/web/20220126162242/https://www.vssc.gov.in/PSLV.html|archive-date=26 January 2022|access-date=27 January 2022}}

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.{{cite web|url=http://www.ias.ac.in/currsci/dec252007/1697.pdf|title=Evolution of Indian launch vehicle technologies|date=25 December 2007 |website=www.ias.ac.in|publisher=Indian Academy of Sciences|archive-url=https://web.archive.org/web/20110524225122/http://www.ias.ac.in/currsci/dec252007/1697.pdf|archive-date=24 May 2011|url-status=dead}}{{cite web|url=http://spl.gov.in/nsss2016/Program/web/SPS/SPS-1-2.pdf|title=Future of Space Transportation: S. Somanath|date=9 February 2016|archive-url=https://web.archive.org/web/20181024195940/http://spl.gov.in/nsss2016/Program/web/SPS/SPS-1-2.pdf|archive-date=24 October 2018|url-status=dead}}{{cite web |url=https://www.mcgill.ca/iasl/files/iasl/Session_3_KRS_Murthi.pdf |archive-url=https://web.archive.org/web/20221010085517/https://www.mcgill.ca/iasl/files/iasl/Session_3_KRS_Murthi.pdf |archive-date=2022-10-10|url-status=live|title=Space Debris Mitigation – Coordination and Implementation efforts in India|last=Murthi|first=K.R. Sridhara|date=9 May 2009|access-date=22 November 2017}}{{cite news|url=https://www.newindianexpress.com/states/kerala/2018/jan/02/isros-baby-rocket-to-carry-small-satellites-likely-to-take-off-in-2019-1742052.html|title=ISRO's baby rocket to carry small satellites, likely to take off in 2019|publisher=The New Indian Express|access-date=2018-01-02|archive-date=3 January 2018|archive-url=https://web.archive.org/web/20180103072531/http://www.newindianexpress.com/states/kerala/2018/jan/02/isros-baby-rocket-to-carry-small-satellites-likely-to-take-off-in-2019-1742052.html|url-status=live}}

PSLV - XL:

• The PS1 ignites at T+0 providing 4846{{Spaces|1|nbsp}}kN of thrust.
• Within T+1, 4 out of the 6 boosters ignite on ground, each producing 703 kN of thrust. 7658{{Spaces|1|nbsp}}kN of total thrust is produced by the combined propulsion of the PSOMs and the PS1.
• At around T+23/26, the remaining 2 unlit boosters are air-lit bringing the rocket at its maximum thrust capacity.
• At T+1:10, the first 4 ground-lit PSOMs have depleted its propellant and now separates and falls down to the ocean. The remaining 2 PSOMs and the PS1 continue to burn.
• At T+1:35, the remaining 2 PSOMs complete its 70 seconds burn and separate, leaving the rocket in a Core Alone configuration.
• At T+1:50, the PS1 has completed its 110-second burn and it separates and the Vikas Engine inside the PS2 ignites.
• The second stage burns for around 130 seconds and around T+4 minutes, the second stages shuts off and separates.
• The third stage, which is a solid rocket booster, and burns 80 seconds and then coasts for the remainder of time and around T+8/10 minutes, it separates and the 4th stage ignites to give the rocket a final push into the orbit.
• This 4th stage burn is highly variable and depends on the mass and number of payloads and usually is around 500 seconds long. The 4th stage may shut off around T+16/18 minutes followed by the Payload Deployment.

{{Cite web|title=Flight Profile – PSLV C40 {{!}} Spaceflight101|url=https://spaceflight101.com/pslv-c40/flight-profile/|access-date=2022-02-15|language=en-US|archive-date=13 February 2022|archive-url=https://web.archive.org/web/20220213150054/https://spaceflight101.com/pslv-c40/flight-profile/|url-status=live}}{{Cite web|title=Flight Profile – PSLV C38 {{!}} Spaceflight101|date=23 June 2017 |url=https://spaceflight101.com/pslv-c38/flight-profile/|access-date=2022-02-15|language=en-US|archive-date=15 February 2022|archive-url=https://web.archive.org/web/20220215015926/https://spaceflight101.com/pslv-c38/flight-profile/|url-status=live}}{{Cite web|title=PSLV-C24 Brochure|url=https://www.isro.gov.in/sites/default/files/pslv-c24-brochure.pdf|url-status=dead|website=Isro|access-date=15 February 2022|archive-date=20 March 2022|archive-url=https://web.archive.org/web/20220320182325/https://www.isro.gov.in/sites/default/files/pslv-c24-brochure.pdf}}

{{main|List of PSLV launches}}

{{#section-h: List of PSLV launches | 1993–2009 }}

;Launch system status:

{{legend|#949090|Retired}}

;Decade-wise summary of PSLV launches:

{{Portal|India|Rocketry|Spaceflight}}

• Geosynchronous Satellite Launch Vehicle
• LVM3
• Next Generation Launch Vehicle
• Comparison of orbital launchers families
• Medium-lift launch vehicle, 2,000 to 20,000 kg to LEO
• Comparison of orbital rocket engines
• Comparison of orbital launch systems

{{reflist|30em}}

{{commons category}}

• [http://www.isro.gov.in/launchers/pslv PSLV : Official ISRO Page] {{Webarchive|url=https://web.archive.org/web/20161222143633/http://www.isro.gov.in/launchers/pslv |date=22 December 2016 }}
• [https://web.archive.org/web/20091027104026/http://geocities.com/hari_ghk/pslv.htm India in Space PSLV page]

{{PSLV}}

{{Expendable launch systems}}

{{Indian space programme}}

Category:ISRO space launch vehicles

Category:Vehicles introduced in 1993

Category:Expendable space launch systems