RD-253 explained

RD-253
Country Of Origin:
First Date:RD-253: 1965
RD-275: 1995
RD-275М: 2007
Designer:NPO Energomash, Valentin Glushko
Manufacturer:Proton-PM
Purpose:First stage booster
Associated:Proton
Successor:RD-254, RD-256, RD-275, RD-275М
Status:Operational
Type:liquid
Fuel:UDMH
Mixture Ratio:2.67
Cycle:Staged combustion
Combustion Chamber:1
Nozzle Ratio:26.2
Thrust(Vac):RD-253:
RD-275:
RD-275М:
Thrust(Sl):RD-253:
RD-275:
RD-275М:
Thrust To Weight:156.2
Chamber Pressure:RD-253:
RD-275:
RD-275M:
Specific Impulse Vacuum:RD-253: 316s
RD-275: 316s
RD-275M: 315.8s
Specific Impulse Sea Level:RD-253: 285s
RD-275: 287s
RD-275M: 288s
Gimbal:7.5°, single plane
Dry Weight:RD-253:
RD-275:
RD-275M:

The RD-253 and its later variants, the RD-275 and RD-275M, are liquid-propellant rocket engines developed in the Soviet Union by Energomash. The engines are used on the first stage of the Proton launch vehicle and use an oxidizer-rich staged combustion cycle to power the turbopumps. The engine burns UDMH/N2O4, which are highly toxic but hypergolic and storable at room temperature, simplifying the engine's design.

History

Development of the RD-253 started in 1961. Preliminary investigations and development of the engine and its further production was performed under the guidance of Valentin Glushko and finished in 1963. The RD-253 uses an oxidiser-rich staged combustion cycle. It was used for the first time in July 1965, when six engines powered the first stage of the Proton rocket. Development and production of RD-253 was a qualitative leap forward for rocketry of that time by achieving high levels of thrust, specific impulse and pressure in the combustion chamber. This engine is one of the most reliable engines in the USSR and modern Russia.

As the first stage of the Proton-K rocket used six RD-253 engines, the system played a pivotal role in Russian space missions when this rocket was chosen as a carrier, including the following programs: "Luna", "Venera", "Mars probe", crewed orbital stations "Salyut", "Mir", and it launched several principal modules for ISS. It was widely used for the launches of heavy satellites. The last RD-253 rocket engine was used on a Proton-K rocket and launched on March 30, 2012.

Since the original development of the engine, several modifications were designed that were not flown. One of them was the RD-256 engine, for which development stopped on experimental models. It was not used in flights and was designed for a cancelled vehicle. The RD-254 variant was supplied with an extended nozzle for use in vacuum.

Current state and development

All rights to sell and employ the RD-253 for Proton rocket are held by Energomash which produces it in Perm, Russia.

The modification RD-275 (14D14) appeared as the result of development in 1987–1993, with the purpose to achieve a more powerful version of the engine. Its 7.7% higher thrust was reached by raising pressure in the combustion chamber and enabled an increase of payload mass to geostationary orbit (GEO) up to more than 6000kg (13,000lb). The successful maiden flight of a Proton rocket with the new engine was completed in 1995.

Energomash started the development of next more powerful version of engine in 2001. It has 5.2% higher thrust and has the designation 14D14M (RD-275M). It was designed to allow the rocket to deliver 150kg (330lb) more payload to GEO.

In the period from 2002 to 2003 years some experimental work was completed with this version of the engine. It included four test firings of three experimental RD-275M with a total time of 735s. In the middle of 2005, this engine went into production by government commission. The first launch of a Proton-M with 14D14M engines was launched on July 7, 2007.

The final version RD-275M is sometimes designated as RD-276, but through 2009 the name RD-275M (14D14M) was more common. Some sources points out the cost of production per engine as much as 1.5 million USD and sometimes calls some lower figures around 1 million USD per unit.

Versions

During the years there have been many versions of this engine:

RD-253 Family of Engines
EngineRD-220RD-221RD-222
RD-223
RD-253
RD-253F
RD-254
RD-275
RD-275M
Development1960 1960-1961 1962-1966 1966-1967 1961-1963 1987-1993 2001-2005
Combustion Chamber Pressure14.7MPa16.9MPa 14.7MPa 15.7MPa 16.5MPa
Thrust (Vacuum)1074kN 1120kN 1634kN 1700kN 1635kN 1870kN 1720kN 1750kN 1832kN
Thrust (Sea Level)947kN N/A 1471kN N/A 1474kN 1720kN N/A 1590kN 1671kN
Specific Impulse (Vacuum)306isp 318isp 302isp 314isp 316isp 317isp 328isp 316isp 315.8isp
Specific Impulse (Sea Level)270isp N/A 272isp N/A 285isp 290isp N/A 287isp 288isp
Height2600mm 4200mm 3470mm 5050mm 3000mm 2700mm 4000mm 3050mm 3050mm
Diameter1300mm 2400mm 1460mm 2530mm 1500mm 1490mm 2600mm 1500mm 1500mm
Intended UseN-1 first stage N-1 second stage N-1 first stage N-1 second stage Proton (8K62) first stage R-36M (15А14) first stage UR-700 third stage, Proton and N-1 second stages Proton-M first stage Proton-M first stage
StatusProject (Abandoned) Retired Project (Abandoned) Retired In Production

See also