RD-120, this very influential engine has been the foundations of many engines spanning derivatives in four countries. The Ukrainian RD-801 and RD-810, the Chinese YF-100 and YF-115, as well as the Indian SCE-200 can be traced directly back to the RD-120. The Soviet/Russian RD-170 family of engines base developed on the lessons learned from the RD-120 project. RD-170 family As stated in the History section, the RD-120 was used as the first practical application of the oxidizer rich staged combustion with kerosene propellant at NPO Energomash, before tackling the RD-170. So, while this later family of engines have more aggressive performance parameters and the original project (the RD-123) predates the RD-120, it was indeed the first actual design of the series development. RD-801 and RD-810 While Yuzhnoye propulsion experience had been mostly on hypergolic propellants engines, like the RD-855 or RD-861, they were considered too toxic for modern ecological standards. While they still offer to develop hypergolic propulsion, like in the case of the RD-843 for the Vega's AVUM stage or the Tsyklon-4 project, for the Mayak launch vehicle family a more environmentally friendly LOX and kerosene propellant was decided. Not only had Yuzhnoye mastered the most complex cycle for the propellant (oxidizer rich staged combustion cycle) with the RD-8, but they had worked closely with NPO Energomash during the RD-120 program. The manufacturing is done at its sister company of Yuzhmash in Ukraine, and the RD-120 thrust augmentation project of 2001 to 2003 had been a mixed project between the three companies. On the base of this experience, a family of derivatives engines were proposed. The RD-805 and RD-809 are mostly modifications of the RD-8, but the RD-801 and the RD-810 members of the family can be considered true descendants of the RD-120. One characteristic of this family is the limitation of keeping the preburner output temperature below . SCE-200 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. As per unconfirmed information obtained by WikiLeaks this contract involved the transfer of blueprints only for a rocket engine by the Yuzhnoye Design Office. According to official press release on March 26, 2013 by Ukrainian Ministry of Economic Development and Trade, development of a rocket engine for