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astronautix.com RD-861


Manufacturer Name: RD-861. Government Designation: 11D25. Other Designations: S5.23, D-25. Designer: Yangel. Developed in: 1968-72. Application: Tsyklon 2 and 3 stage 3; Ikar. Used on stages: Tsyklon 2-3, Tsyklon 3-3. Used on launch vehicles: Soyuz 11A510, Tsyklon 2, Tsyklon 3. Propellants: N2O4/UDMH Thrust(vac): 8,026 kgf. Thrust(vac): 78.71 kN. Isp: 317 sec. Burn time: 130 sec. Mass Engine: 123 kg. Diameter: 1.5 m. Length: 1.6 m. Chambers: 1 + 4 + 2. Chamber Pressure: 88.80 bar. Area Ratio: 112.40. Oxidizer to Fuel Ratio: 2.10. Country: Ukraine. Status: In Production. First Flight: 1965. Last Flight: 1998. Flown: 228. References: 42 , 348 . Comments: Based on RD-854. Thrust vector control by 4 nozzles (thrust 98 N each) fed from gas generator. Mass given in ref. IAF-97-S.1.04 is 162 kg instead of 123 kg.
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Last update 12 March 2001.
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