@Lonewolf I got an update for you about SCE-200, this update is from Strategic Frontier Forum
The SCE-200 engine began life with ISRO acquiring the Ukrainian RD-810 semi-cryogenic engine blueprints from the Yuzhnoye Design Bureau in 2005. The design of the engine was the only thing that was acquired. Other vital stuff like the mathematical models, materials used etc. were not brought.
This means ISRO had know how without the know why. So they had to reverse engineer the know why. Along the way ISRO made modifications to the engine design, materials, production methods, fuel etc. thus making the SCE-200 engine a derivative of the RD-810 not an exact replica. Besides the Ukrainians themselves have never built the RD-810, so you can't really say its a proven design.
The engine was originally designed to use RP-1 as the fuel. ISRO wanted to use their own Kerosene derivative called the Isrosene. The original design assumed most of the components of the rocket will be made conventionally by using processes like investment casting, ISRO began 3D printing the components. Reverse engineering the know how and making changes to the original design took around a decade.
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Low Pressure Oxidiser Turbo(LPOT) pump.
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Some breakthroughs made in metallurgy
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Single element thrust chamber hot test
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Injector design experiments
Component level testing began in around 2015. Small scale tests were conducted to fix the propellant to oxidiser ratio for Isrosene. Igniters were also designed and tested. New materials were being experimented with. Components level testing continued for another 2 years, in 2017 ISRO signed an agreement with the Yuzhmash production facility for hot testing full sized engine components. The entire engine was planned to be tested in India.
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Aerial view of the propulsion testing facility at the Yuzhmash plant in Dnipro, Ukraine.
ISRO Propulsion Complex (IPRC) in Mahendragiri had set up a Semi-cryogenic Cold Flow Test facility (SCFT) for the development, qualification and acceptance testing of semi-cryogenic engine subsystems. this is where most sub-systems were tested till date. IPRC were also sanctioned by ISRO to build a new test stand for hot fire testing of the full sized engine. A new test stand is needed as the current test stand was simply inadequate for handling the ~2MN thrust output of the SCE-200. But that project got delayed due to unknown reasons. As of 2021 the new test stand is yet to be completed.
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Satellite image of the under construction new test stand from 2018.
ISRO had sent Indian made engine components to Ukraine in 2018-2019 period. The component tests were supposed to end by 2019. After the tests end the components would be shipped back to India where they would be assembled to build a full sized engine. No news was heard of the SCE-200 component tests in the Indian, Ukrainian or any other media. At least nothing on the English language media. If something was published in the Ukrainian/Russian language media then I have missed it.
And now comes the hypothetical part:
In November 2020, a video was put out on Youtube about the Yuzhmash engine plant :
An Ukrainian member posted this on NASASpaceflight forum suggesting that a new engine shown in that video was the SCE-200 engine. The narrator in the video remarks the engine was a unique design & produces tremendous thrust. Then the narrator adds that the engine belongs to a foreign nation adding they will not disclose which nation it is.
Here are some screenshots of the engine :
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This Engine is supposedly SCE-200
I initially dismissed this as some other engine of some other country. But now I think it may be the SCE-200 after all. In a recent presentation Dr. S. Somanath showed slides that put the estimated timeline of the development of a SC400 rocket stage based on the SCE-200 engines to be a just 2 years away. That would naturally mean the engine is very close to being ready.
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After seeing the above slide, I wonder whether ISRO is planning Manned Gaganyaan flight using the HLV, because the timelines mentioned for Human-rated HLV (2023) match with that of 1st Manned Gaganyaan flight.
Last year there was a tender for making trailers for the SC120 stage to be used in the GSLV Mk-3 augmentation project. If they are calling tenders for trailers for the SC120, surely design of the stage has been finalised. There is no way of finalising a rocket stage design without testing the engine prototypes. Looking at it from that POV it does seem likely that the engine shown above is indeed the SCE-200. Maybe the agreement between ISRO and Yuzhmash stretches beyond hot testing engine components. Maybe they would assemble the engine and conduct hot tests on it too.
When ISRO acquired the RD-810 blueprints from the Yuzhnoye Design Bureau they offered to help design an entire launch rocket based on that engine. Of course from the RD-810 to the SCE-200 the engine design has changed quite a bit. Wonder if that offer still stands.
