CE-7.5

CE-7.5 is a regeneratively-cooled, variable-thrust, fuel-rich staged combustion cycle rocket engine.{{cite web |url=http://www.isro.org/gslv-d3/pdf/GSLV-D3_GSAT-4%20Brochure.pdf |title=GSLV-D3 brochure |publisher=ISRO |url-status=dead |archive-url=https://web.archive.org/web/20140207165809/http://www.isro.org/gslv-d3/pdf/GSLV-D3_GSAT-4%20Brochure.pdf |archive-date=February 7, 2014 }}{{cite news |url=http://www.frontline.in/cover-story/gslv-mkiii-the-next-milestone/article5596588.ece |title=GSLV MkIII, the next milestone |work=Frontline |date=2014-02-07 }}

The specifications and key characteristics of the engine are:

• Operating Cycle – Staged combustion
• Propellant Combination – LOX / LH2{{cite web |url=http://www.isro.gov.in/gslv-d5/cryogenic-engine.aspx |title=Indigenous Cryogenic Upper Stage |access-date=27 September 2014 |url-status=dead |archive-url=https://web.archive.org/web/20140806173146/http://isro.gov.in/gslv-d5/cryogenic-engine.aspx |archive-date=6 August 2014 }}
• Maximum thrust (Vacuum) – 73.55 kN{{cite web |url=http://www.isro.gov.in/gslv-d5/gslv-d5.aspx |title=GSLV-D5 |publisher=ISRO |access-date=27 September 2014 |url-status=dead |archive-url=https://web.archive.org/web/20141006082545/http://www.isro.gov.in/gslv-d5/gslv-d5.aspx |archive-date=6 October 2014 }}
• Operating Thrust Range (as demonstrated during GSLV Mk2 D5 flight) – 73.55 kN to 82 kN {{cite web |url=https://www.youtube.com/watch?v=Y7HIvfhoFHM#t=3024 |archive-url=https://ghostarchive.org/varchive/youtube/20211221/Y7HIvfhoFHM |archive-date=2021-12-21 |url-status=live| title=GSLV-D5 launch video – CE-7.5 thrust was uprated by 9.5% to 82 kN and then brought back to nominal thrust of 73.55 kN | publisher=Doordarshan National TV}}{{cbignore}}
• Engine Specific Impulse - {{convert|454|±|3|isp}}
• Engine Burn Duration (Nom) – 720 seconds
• Propellant Mass – 12,800 kg
• Two independent regulators: thrust control and mixture ratio control
• Steering during thrust: provided by two gimballed steering engines

The Indian Space Research Organisation (ISRO) formally started the Cryogenic Upper Stage Project in 1994.{{cite web|url=http://articles.economictimes.indiatimes.com/2014-01-09/news/46030395_1_cryogenic-engine-mahendragiri-isro|archive-url=https://web.archive.org/web/20140110225529/http://articles.economictimes.indiatimes.com/2014-01-09/news/46030395_1_cryogenic-engine-mahendragiri-isro|url-status=dead|archive-date=10 January 2014|title=How ISRO developed the indigenous cryogenic engine|work=The Economic Times}} The engine successfully completed the Flight Acceptance Hot Test in 2008,{{cite web|url=http://www.isro.gov.in/hi/node/591|title=Flight Acceptance Hot Test Of Indigenous Cryogenic Engine Successful|publisher=ISRO|access-date=8 January 2014|archive-date=30 June 2016|archive-url=https://web.archive.org/web/20160630124416/http://www.isro.gov.in/hi/node/591|url-status=dead}} and was integrated with propellant tanks, third-stage structures and associated feed lines for the first launch. The first flight attempt took place in April 2010 during the GSLV Mk.II D3/GSAT-3 mission. The engine ignited, but the ignition did not sustain as the Fuel Booster Turbo Pump (FBTP) shut down after reaching a speed of about 34,500 rpm 480 milliseconds after ignition, due to the FBTP being starved of Liquid Hydrogen (LH2). On 27 March 2013 the engine was successfully tested under vacuum conditions. The engine performed as expected and was qualified to power the third stage of the GSLV Mk-2 rocket. On 5 January 2014 the cryogenic engine performed successfully and launched the GSAT-14 satellite in the GSLV-D5/GSAT-14 mission.{{cite web |url=http://www.isro.gov.in/gslv-d5/mission.aspx |title=Welcome to Indian Space Research Organisation - GSLV-D5/GSAT-14 Mission |access-date=2014-01-05 |url-status=dead |archive-url=https://web.archive.org/web/20140104230506/http://www.isro.gov.in/gslv-d5/mission.aspx |archive-date=2014-01-04 }}{{cite web|title=Indigenous Cryogenic Upper Stage Successfully Flight Tested On-board GSLV-D5|url=http://www.isro.org/pressrelease/scripts/pressreleasein.aspx?Jan06_2014|publisher=ISRO|access-date=6 January 2014|archive-url=https://web.archive.org/web/20140108174921/http://www.isro.org/pressrelease/scripts/pressreleasein.aspx?Jan06_2014|archive-date=8 January 2014|url-status=dead}}

To aid in the development of NGLV, technologies for multiple restart and development of a spark torch igniter was conducted on the Vernier engine of the GSLV CUS in March 2025.{{Cite web |title=Multiple restarts of Launch Vehicle Stages - ISRO successfully carried out ignition trial using Spark Torch Igniter |url=https://www.isro.gov.in/ISROsuccessfullycarriedoutSparkTorchIgniter.html |access-date=2025-03-08 |website=www.isro.gov.in}}

CE-7.5 is being used in the third stage of ISRO's GSLV Mk.II rocket.{{Cite web|url=http://www.isro.gov.in/launchers/gslv|title=GSLV - Isro|access-date=31 May 2016|archive-date=4 September 2015|archive-url=https://web.archive.org/web/20150904075443/http://www.isro.gov.in/launchers/gslv|url-status=dead}}

{{Portal|India|Rocketry|Spaceflight}}

• CE-20
• SCE-200
• LVM3
• GSLV

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{{Indian space programme}}

{{Rocket engines}}

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Category:Rocket engines of India

Category:Rocket engines using hydrogen propellant

Category:Rocket engines using the staged combustion cycle