The LR105 is a

liquid-fuel rocket A liquid-propellant rocket or liquid rocket uses a rocket engine burning liquid propellants. (Alternate approaches use gaseous or solid propellants.) Liquids are desirable propellants because they have reasonably high density and their combustio ...

engine that served as the sustainer engine for the

Atlas rocket Atlas is a family of US missiles and space launch vehicles that originated with the SM-65 Atlas. The Atlas intercontinental ballistic missile (ICBM) program was initiated in the late 1950s under the Convair Division of General Dynamics. Atlas wa ...

family. Developed by

Rocketdyne Rocketdyne is an American rocket engine design and production company headquartered in Canoga Park, California, Canoga Park, in the western San Fernando Valley of suburban Los Angeles, California, Los Angeles, in southern California. Rocketdyne ...

in 1957 as the S-4, it is called a sustainer engine because it continues firing after the LR89 booster engines have been jettisoned, providing thrust during the ascent phase.

Description

The LR105 is a liquid-propellant engine using

RP-1 RP-1 (Rocket Propellant-1 or Refined Petroleum-1) and similar fuels like RG-1 and T-1 are highly refined kerosene formulations used as rocket fuel. Liquid-fueled rockets that use RP-1 as fuel are known as kerolox rockets. In their engines, RP- ...

LOX Lox is a fillet of brined salmon, which may be smoked. Lox is frequently served on a bagel with cream cheese, and often garnished with tomato, onion, cucumber, and capers. Etymology The American English word ''lox'' is a borrowing of Yiddi ...

. The engine operates on a

gas-generator cycle The gas-generator cycle, also referred to as the GG cycle or colloquially as an open cycle, is one of the most commonly used power cycles in bipropellant liquid rocket engines. Propellant is burned in a gas generator (analogous to, but distinct ...

, where a small portion of the propellant is burned in a gas generator to drive the

turbopump A turbopump is a fluid pump with two main components: a rotodynamic pump and a driving gas turbine, usually both mounted on the same shaft, or sometimes geared together. They were initially developed in Germany in the early 1940s. The most co ...

s, which supply the engine with fuel and oxidizer. The engine was designed to be throttleable, meaning its thrust could be adjusted during flight to optimize performance. The LR105 also features

regenerative cooling Regenerative cooling is a method of cooling gases in which compressed gas is cooled by allowing it to expand and thereby take heat from the surroundings. The cooled expanded gas then passes through a heat exchanger where it cools the incoming com ...

, where RP-1 fuel is circulated through cooling channels in the engine's nozzle and combustion chamber before being injected into the combustion process, preventing overheating and improving efficiency.

Versions

The LR105 engine underwent several upgrades over its operational life, leading to multiple variants:

References

Rocket engines using kerosene propellant Rocketdyne engines Rocket engines using the pressure-fed cycle Rocket engines of the United States Atlas (rocket family) {{rocketry-stub

Description

Versions

See also

References