# SCE-200

The SCE-200 (also referred as Semi-Cryogenic Engine-200) is a 2 MN thrust class liquid rocket engine, being developed to power Indian Space Research Organisation's (ISRO) existing LVM3 and upcoming heavy and super heavy-lift launch vehicles. It is being developed by the Liquid Propulsion Systems Centre (LPSC) of ISRO, and is expected to have first flight in 2020s.
Burning liquid oxygen (LOX) and RP-1 kerosene in an oxidizer-rich staged combustion cycle, the engine will boost payload capacity of LVM3 replacing current L110 stage powered by 2 Vikas engines. It is also expected to power ISRO's upcoming Next Generation Launch Vehicle (NGLV) rockets (previously planned as ULV) as well as ISRO's future reusable rockets based on RLV technology demonstrations.
The engine in September 2019 reportedly had become ready to begin testing in Ukraine and enter service no earlier than 2022. The use of engine of India's first human spaceflight, hence was ruled out by ISRO. By November 2022, SCE-200 had neared completion of its qualification tests. The Semi-Cryogenic Engine and Stage Test Facility at the ISRO Propulsion Complex Mahendergiri was preparing for ground tests now that the SCE-200 had reached the final stages of development.

## Background

On June 2, 2005, India and Ukraine signed the Framework Agreement between the Government of Ukraine and the Government of the Republic of India on Cooperation in the Peaceful Uses of Outer Space, which would enter in force on February 15, 2006. Agreement also involved the transfer of blueprints for a rocket engine by the Yuzhnoye Design Office. The engine blueprints supposedly transferred by Ukraine to India, have been identified as the RD-810 which in turn is a variant of Russian RD-120.
According to official press release on March 26, 2013, by Ukrainian Ministry of Economic Development and Trade, development of a rocket engine for Indian launch vehicles initiated in 2006 under a joint Indian-Ukrainian project named "Jasmine".

## History

In 2009, SCE-200 program was approved for ₹1,798 crore (US$210 million) and program to develop a 2 MN class main engine began.
During May and June 2015, ISRO and Roscosmos signed a wide-ranging Memorandum of Understanding for cooperation in space. A. S. Kiran Kumar, Chairman of the ISRO, stated that one of the first benefits would be the availability of Russian test stand for initial testing of the SCE-200, while the Mahendragiri semi-cryogenic test stand being built. The engine is a part of the ₹1,800 crore (US$210 million) semi-cryogenic launch vehicle program, which would be capable of placing 6,000–10,000 kilograms (13,000–22,000 lb) in GTO. The engine however will not be the part of first flight of Gaganyaan, India's first crewed mission to space, given timelines and schedules.
In 2017, Ukrainian firm Yuzhmash was contracted by ISRO to conduct tests on critical components of SCE-200. First stage of contract was reportedly complete and tests were expected to be completed by 2019. In April 2022, ISRO chairman S. Somanath stated that tests within the country were to begin in next 3 months. By November 2022, the test facility and stand had been nearly ready for engine as well as SC120 stage test which would upgrade India's existing LVM3 rocket.

## Development and testing

* On 10 May 2023, the first integrated test of 2000 kN semi-cryogenic engine on an intermediate configuration was conducted at Semi cryogenic Integrated Engine & Stage Test (SIET) facility in ISRO Propulsion Complex (IPRC). During the test, complex chill-down operations were performed to meet necessary conditions for engine start.
* On 1 July 2023, the first hot test with intermediate configuration of the semi-cryogenic engine, known as Power Head Test Article (PHTA) was conducted at SIET facility. The test proceeded nominally till 1.9 seconds validating the ignition and subsequent performance of PHTA. At 2.0 seconds, an unexpected spike in the turbine pressure and subsequent loss of turbine-speed was observed. The test was terminated mid-way as a precaution. The intended duration of test was 4.5 seconds to validate the performance of the gas generator, turbo pumps, pre-burner and control components with focus on the ignition and hot-gas generation within the pre-burner chamber.
* On 2 May 2024, first ignition trial of Pre-burner Ignition Test Article (PITA) was conducted nominally at SIET facility. PITA is a full complement of the engine power head system but without turbo pumps. It was proved that the pre-burner could ignite smoothly and continuously. A start fuel ampule that combines triethylaluminium and triethyleboron created by Vikram Sarabhai Space Centre (VSSC) is used to ignite semi-cryogenic engine and utilized for the first time in ISRO's 2000 kN semi-cryogenic engine. For characterization, injector elemental level ignition tests were carried out at the VSSC Propulsion Research Laboratory Division (PRLD). Additionally, work is being done on the creation of a semi-cryogenic stage that can load 120 tons of propellant.Preburner ignition test article and Hot test