RD-191

The RD-191 is expected in service in 2009 and will be used on the Angara Launch Vehicle Family which is being built by Khrunichev Space R&D Center.

The RD 191 as a main engine should have a capability of thrust vector control (TVC) as well as a capability to function during a long time in the mode of lowered thrust (down to 30% of nominal level) for its applications in core units of intermediate/heavy launchers.

In addition the engine will be able for a longer period of time as the Angara Core, whereas in the strap-on booster form the RD 191 will work for less time.

An adoption of such an important component as the combustion chamber from the RD-171 and RD-180 engines allowed not only to decrease development cost and duration for the RD-191 but also to enhance a confidence in reliability and operational functionality of the new engine.

The RD-191 is an oxygen/kerosene engine which is designed in the framework of generator gas after-burning concept with a capability of combustion chamber’s deflection in a Cardan suspension. An ignition is provided by a chemical method, by feeding into the combustion chamber special starting fuel, which is self-ignited when in contact with liquid oxygen (oxidizer).

Besides a mode of throttling down to 30% of nominal thrust, the engine allows also a short-time burning in a mode of enhanced thrust (up to 5% of nominal level) in emergency situations.

TVC in channels of pitch and jaw is provided by deflections of combustion chamber in a Cardan suspension. Besides this, the engine can feed a generator gas for running of nozzles providing control on a roll channel. This feature of the engine is crucial for control of the first stages of light-weight launch vehicles and of the core boosters of intermediate/heavy launch vehicles. The engine fulfils two additional functions:

• heating of gas (helium) for a pressurization of propellant tanks and

• bleeding of fuel after a pump for running of hydraulic actuators providing deflections of combustion chamber and aerodynamic rudders.

Engine's design includes pipelines, valves and fittings of automatics and control, that provide functioning of the engine in various modes. The engine RD-191 is also equipped with sensors for telemetry measurements of the burning parameters in flight and with an equipment of monitoring / emergency protection system. The last system is intended for countering emergency situations during the flight.

History

The RD-191 engine was just “fitted” to the universal rocket module. In March 1999 its first mock-up/technological sample was delivered to Khrunichev and was installed on the engineering mock-up.