The engine chamber is intended for conversion of propellant's chemical energy into kinetic energy of ejected combustion products with following thrust generation.
The chamber is designed for RD-8, the steering four-chamber engine capable to control flight of Zenit LV second stage in pitch/yaw/roll channels.

• The chamber has high power characteristics and long burn time.
• It is provided with turnable joints that allow gimballing in one plane with delivery of generator gas and kerosene through them.
• The propellant is ignited chemically by starting fuel.
• Status of development - serial production.

The chamber operates under a scheme of oxidizer-rich generator gas afterburning.

	Vacuum thrust, kN (kgf)	19,620 (2000)
	Vacuum specific impulse, m/s (s)	3360,9 (342,6)
	Absolute chamber pressure, MPa (kgf/cm2)	7,84 (80)
	Absolute nozzle exit pressure, MPa (kgf/cm2)	0,0049 (0,05)
	Propellants: - oxidizer - fuel	oxygen kerosen RG-1
	Mixture ratio	2,4
	Absolute inlet propellant pressure, MPa (kgf/cm2): - oxidizer - fuel	10,06 (103) 15,19 (155)
	Working gimbal angle, deg	<±33
	Disbalance, kgf x m, max	3
	Friction moment, kgf x m, max	0,6
	Burn time, s: - specified - confirmed	1100 5000
	Mass with turnable joints, kg, max	36,5

RD-855, RD-856 and RD-863 engine chambers

The engine chambers are intended for conversion of propellant's chemical energy into kinetic energy of ejected combustion products with following thrust generation.
The chamber of RD-855 engine is designed for the steering four-chamber engine capable to control flight of Cyclone LV fist stage in pitch/yaw/roll channels.through gimballing each chamber in one plane.
The chamber of RD-856 engine is designd for the steering four-chamber engine capable to control flight of Cyclone LV second stage in pitch/yaw/roll channels.through gimballing each chamber in one plane.
The chamber of RD-863 engine is designd for the steering four-chamber engine capable to control flight of the first stage in pitch/yaw/roll channels.through gimballing each chamber in one plane.

• The said chambers have high power characteristics.
• They are provided with turnable joints that allow gimballing in one plane with delivery of propellants through them.
• Development of chambers is completed, and they are serially produced.

The chambers are intended for operation on hypergolic propellants under the generator scheme.

RD-855 chamber	RD-856 chamber	RD-863 chamber

Parameter	RD-855 chamber	RD-856 chamber	RD-863 chamber
Sea level thrust, kN (kgf)	70,632 (7200)	13,488 (1375) in vacuum	79,147 (8068)
Vacuum specific impulse, m/s (s)	2864,5 (292)	2751,7 (280,5)	2952,8 (301)
Absolute chamber pressure, MPa (kgf/cm2)	6,57 (67)	7,16 (73)	8,88 (90,5)
Absolute nozzle exit pressure, MPa (kgf/cm2)	0,0589 (0,6)	0,0245 (0,25)	0,0486 (0,495)
Propellants: - oxidizer - fuel	NTO UDMH
Mixture ratio	2,3	2,14	2,38
Absolute inlet propellant pressure, MPa (kgf/cm2): - oxidizer - fuel	8,29 (84,5) 10,06 (105,5)	8,34 (85) 8,82 (90)	11,82 (120,5) 13,29 (135,5)
Working gimbal angle, deg	±41	±30	±38
Disbalance, kgf x m, max	0,8	0,3	0,8
Friction moment, kgf x m, max	0,5	0,3	0,8
Burn time, s: - specified - confirmed	157 350	193 290	130 850
Mass, kg, max	35,5	10,59	34,75

RD-858 engine chamber

The engine chamber is intended for conversion of propellant's chemical energy into kinetic energy of ejected combustion products with following thrust generation.
The chamber is designed for the main engine of propulsion cluster in composition of the Lunar Vehicle intended for a soft landing onto the Moon surface with following lift-off and placing of the Vehicle into elliptic orbit of the Moon.

The development was closed in the flight test phase because of of the Project termination.

• The chamber has high power characteristics.
• It is able to operate at deep thrust throttling.

	Parameter	main mode	throttled mode
	Vacuum thrust, kN (kgf)	19,473 (1985)	8,034 (819)
	Vacuum specific impulse, m/s (s)	3178,4 (324)	2884,1 (294)
	Absolute chamber pressure, MPa (kgf/cm2)	7,85 (80)	3,32 (33,8)
	Absolute nozzle exit pressure, MPa (kgf/cm2)	0,0049 (0,5)	0,002 (0,02)
	Propellants: - oxidizer - fuel	NTO UDMH
	Mixture ratio	2,36	1,87
	Absolute inlet propellant pressure, MPa (kgf/cm2): - oxidizer - fuel	11,14 (113,5) 12,75 (130)	3,96 (40,5) 7,05 (71,8)
	Burn time, s: - specified - confirmed	470 3600
	Mass without attachment structure, kg	17

RD-859 engine chamber

The engine chamber is intended for conversion of propellant's chemical energy into kinetic energy of ejected combustion products with following thrust generation.
The chamber is designed for the stand-by two-chamber engine of propulsion cluster in composition of the Lunar Vehicle intended for a soft landing onto the Moon surface with following lift-off and placing of the Vehicle into elliptic orbit of the Moon.
The development was closed in the flight test phase because of of the Project termination.

The chamber has high power characteristics.

The chamber is intended for operation on hypergolic propellants under the generator scheme.

	Vacuum thrust, kN (kgf)	1,02 (994)
	Vacuum specific impulse, m/s (s)	3136,3 (319,7)
	Absolute chamber pressure, MPa (kgf/cm2)	7,85 (80)
	Absolute nozzle exit pressure, MPa (kgf/cm2)	0,0049 (0,05)
	Propellants: - oxidizer - fuel	NTO UDMH
	Mixture ratio	2,287
	Absolute inlet propellant pressure, MPa (kgf/cm2): - oxidizer - fuel	9,71 (100) 11,68 (119)
	Burn time, s: - specified - confirmed	370 3600
	Mass, kg	10

RD-861 engine chamber

The engine chamber is intended for conversion of propellant's chemical energy into kinetic energy of ejected combustion products with following thrust generation.
The chamber is designed for thrust creation during Cyclone LV third stage.
The chamber status - serial production.

• The chamber has high power characteristics at small weight.
• The nozle's supersonic part is composed of thin-walled profiled high-pressure tubes.

The chamber is intended for operation on hypergolic propellants under the generator scheme.

	Vacuum thrust, kN (kgf)	75,213 (776,7)
	Vacuum specific impulse, m/s (s)	3243,2 (330)
	Absolute chamber pressure, MPa (kgf/cm2)	8,878 (90,5)
	Absolute nozzle exit pressure, MPa (kgf/cm2)	0,0052 (0,053)
	Propellants: - oxidizer - fuel	NTO UDMH
	Mixture ratio	2,64
	Absolute inlet propellant pressure, MPa (kgf/cm2): - oxidizer - fuel	13,68 (139,5) 13,24 (135)
	Burn time, s: - specified - confirmed	130 500
	Mass, kg	44

RD-866 engine chamber

The restartable engine chamber is intended for conversion of propellant's chemical energy into kinetic energy of ejected combustion products with following thrust generation.
The chamber is designed for the upper stage engine and capable to control flight of the stage in pitch and yaw channels by gimballing in two orthogonal planes.
Status of development - serial production.

• The chamber has high mass-power characteristics owing to utilization of uncooled nozzle's skirt and effective system of internal film cooling.
• The chamber is provided with mechanical interfaces that allow its gimballing intwo planes.

The chamber is intended for operation on hypergolic propellants under the generator scheme.

	Vacuum thrust, kN (kgf)	5,037 (513,5)
	Vacuum specific impulse, m/s (s)	3169,6 (323,1)
	Absolute chamber pressure, MPa (kgf/cm2)	4,07 (41,5)
	Absolute nozzle exit pressure, MPa (kgf/cm2)	0,0024 (0,0245)
	Propellants: - oxidizer - fuel	NTO UDMH
	Mixture ratio	2,31
	Absolute inlet propellant pressure, MPa (kgf/cm2): - oxidizer - fuel	6,15 (62,7) 6,84 (69,7)
	Gimbal angle, deg	±20
	Friction moment, kgf x m, max	0,5
	Burn time, s: - specified - confirmed	330 1000
	Number of restarts	14
	Mass, kg, max	9,2

RD-868 engine chamber

The engine chamber is intended for conversion of propellant's chemical energy into kinetic energy of ejected combustion products with following thrust generation.
The chamber is designed for LV apogee stage engine and capable to control flight of the stage in pitch and yaw channels by gimballing in two orthogonal planes.

• The Conceptual Design and design documentation are issued, autonomous development is performed.
• The chamber has high mass-power characteristics owing to utilization of uncooled nozzle's skirt and effective system of internal film cooling.

The chamber is intended for operation on hypergolic propellants under the generator scheme.

	Vacuum thrust, kN (kgf)	22,867 (2331)
	Vacuum specific impulse, m/s (s)	3226,4 (329)
	Absolute chamber pressure, MPa (kgf/cm2)	9,15 (93,3)
	Absolute nozzle exit pressure, MPa (kgf/cm2)	0,0027 (0,028)
	Propellants: - oxidizer - fuel	NTO UDMH
	Mixture ratio	2,4
	Absolute inlet propellant pressure, MPa (kgf/cm2): - oxidizer - fuel	12,09 (123,3) 13,56 (138,3)
	Gimbal angle, deg	±8
	Disbalance, kgf x m, max	1,5
	Burn time, specified and confirmed, s	1600
	Mass, kg	24,8

RD-869 engine chamber

The engine chamber is intended for conversion of propellant's chemical energy into kinetic energy of ejected combustion products with following thrust generation, as well as to control flight of the space tug in pitch/yaw/roll channels by gimballing four chambers in one plane each.
The chamber is designed for four-chamber, two-mode, one-run, pump-fed engine with hypergolic propellants.
Status of development - serial production.

• The chamber has high mass-power characteristics.
• It operates in main mode (MM) and throttled one (TM), with multiple transfer from one mode to another.
• The chamber is provided with turnable joint that allow gimballing in one plane with delivery of propellants through it.
• Specifc feature - utilization of uncooled nozzle's skirt and effective system of internal film cooling.

The chamber is intended for operation on hypergolic propellants under the generator scheme.

	Parameter	main mode	throttled mode
	Vacuum thrust, kN (kgf)	5,052 (515)	2,07 (211)
	Vacuum specific impulse, m/s (s)	3134,3 (320)	3065,6 (312,5)
	Absolute chamber pressure, MPa (kgf/cm2)	4,1 (41,8)	1,7 (17,3)
	Absolute nozzle exit pressure, MPa (kgf/cm2)	0,0026 (0,0222)	0,001 (0,0094)
	Propellants: - oxidizer - fuel	NTO UDMH
	Mixture ratio	1,92	2
	Absolute inlet propellant pressure, MPa (kgf/cm2): - oxidizer - fuel	6,36 (64,8) 7,04 (71,8)	2,11 (21,5) 2,18 (22,2)
	Gimbal angle, deg	±55
	Disbalance, kgf x m, max	0,3
	Friction torque for break-away and motion, kgf x m, max	0,2
	Burn time, specified and confirmed, s	1600
	Mass, kg	24,8