The LR105 is a liquid-fuel rocket engine that served as the sustainer engine for the Atlas rocket family. [1] [2] [3] Developed by Rocketdyne in 1957 as the S-4, [4] [5] [6] it is called a sustainer engine because it continues firing after the LR89 booster engines have been jettisoned, providing thrust during the ascent phase. [7]
The LR105 is a liquid-propellant engine using RP-1/LOX. The engine operates on a gas-generator cycle, where a small portion of the propellant is burned in a gas generator to drive the turbopumps, 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, 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.
The LR105 engine underwent several upgrades over its operational life, leading to multiple variants: [1] [8] [9] [10] [3]
Version | Year | Thrust (kN) | Specific impulse (s) | Burn Time (s) | Details |
---|---|---|---|---|---|
LR105-3 | 1957 | 375.00 | 308 | Atlas A, Atlas B | |
XLR105-5 | 1958 | 363.20 | 309 | 335 | Atlas-Able, Atlas B, Atlas-Centaur, Atlas D, Atlas-Agena, Atlas LV-3B |
LR105-5 | 1958 | 386.40 | 316 | 430 | Atlas-Centaur, Atlas E, Atlas-Agena, Atlas F, Atlas SLV-3 |
LR105-7 | 1963 | 386.40 | 316 | 266 | Atlas Agena, Atlas F, Atlas H, Atlas G, Atlas I |
A tripropellant rocket is a rocket that uses three propellants, as opposed to the more common bipropellant rocket or monopropellant rocket designs, which use two or one propellants, respectively. Tripropellant systems can be designed to have high specific impulse and have been investigated for single-stage-to-orbit designs. While tripropellant engines have been tested by Rocketdyne and NPO Energomash, no tripropellant rocket has been flown.
A rocket engine uses stored rocket propellants as the reaction mass for forming a high-speed propulsive jet of fluid, usually high-temperature gas. Rocket engines are reaction engines, producing thrust by ejecting mass rearward, in accordance with Newton's third law. Most rocket engines use the combustion of reactive chemicals to supply the necessary energy, but non-combusting forms such as cold gas thrusters and nuclear thermal rockets also exist. Vehicles propelled by rocket engines are commonly used by ballistic missiles and rockets. Rocket vehicles carry their own oxidiser, unlike most combustion engines, so rocket engines can be used in a vacuum to propel spacecraft and ballistic missiles.
The expander cycle is a power cycle of a bipropellant rocket engine. In this cycle, the fuel is used to cool the engine's combustion chamber, picking up heat and changing phase. The now heated and gaseous fuel then powers the turbine that drives the engine's fuel and oxidizer pumps before being injected into the combustion chamber and burned.
Rocketdyne is an American rocket engine design and production company headquartered in Canoga Park, in the western San Fernando Valley of suburban Los Angeles, in southern California.
RP-1 (alternatively, Rocket Propellant-1 or Refined Petroleum-1) is a highly refined form of kerosene outwardly similar to jet fuel, used as rocket fuel. RP-1 provides a lower specific impulse than liquid hydrogen (H2), but is cheaper, is stable at room temperature, and presents a lower explosion hazard. RP-1 is far denser than H2, giving it a higher energy density (though its specific energy is lower). RP-1 also has a fraction of the toxicity and carcinogenic hazards of hydrazine, another room-temperature liquid fuel.
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 combustion products have high specific impulse (Isp). This allows the volume of the propellant tanks to be relatively low.
The F-1 is a rocket engine developed by Rocketdyne. The engine uses a gas-generator cycle developed in the United States in the late 1950s and was used in the Saturn V rocket in the 1960s and early 1970s. Five F-1 engines were used in the S-IC first stage of each Saturn V, which served as the main launch vehicle of the Apollo program. The F-1 remains the most powerful single combustion chamber liquid-propellant rocket engine ever developed.
The J-2, commonly known as Rocketdyne J-2, was a liquid-fuel cryogenic rocket engine used on NASA's Saturn IB and Saturn V launch vehicles. Built in the United States by Rocketdyne, the J-2 burned cryogenic liquid hydrogen (LH2) and liquid oxygen (LOX) propellants, with each engine producing 1,033.1 kN (232,250 lbf) of thrust in vacuum. The engine's preliminary design dates back to recommendations of the 1959 Silverstein Committee. Rocketdyne won approval to develop the J-2 in June 1960 and the first flight, AS-201, occurred on 26 February 1966. The J-2 underwent several minor upgrades over its operational history to improve the engine's performance, with two major upgrade programs, the de Laval nozzle-type J-2S and aerospike-type J-2T, which were cancelled after the conclusion of the Apollo program.
The Rocketdyne H-1 was a 205,000 lbf (910 kN) thrust liquid-propellant rocket engine burning LOX and RP-1. The H-1 was developed for use in the S-I and S-IB first stages of the Saturn I and Saturn IB rockets, respectively, where it was used in clusters of eight engines. After the Apollo program, surplus H-1 engines were rebranded and reworked as the Rocketdyne RS-27 engine with first usage on the Delta 2000 series in 1974. RS-27 engines continued to be used up until 1992 when the first version of the Delta II, Delta 6000, was retired. The RS-27A variant, boasting slightly upgraded performance, was also used on the later Delta II and Delta III rockets, with the former flying until 2018.
The RL10 is a liquid-fuel cryogenic rocket engine built in the United States by Aerojet Rocketdyne that burns cryogenic liquid hydrogen and liquid oxygen propellants. Modern versions produce up to 110 kN (24,729 lbf) of thrust per engine in vacuum. Three RL10 versions are in production for the Centaur upper stage of the Atlas V and the DCSS of the Delta IV. Three more versions are in development for the Exploration Upper Stage of the Space Launch System and the Centaur V of the Vulcan rocket.
The staged combustion cycle is a power cycle of a bipropellant rocket engine. In the staged combustion cycle, propellant flows through multiple combustion chambers, and is thus combusted in stages. The main advantage relative to other rocket engine power cycles is high fuel efficiency, measured through specific impulse, while its main disadvantage is engineering complexity.
The gas-generator cycle, also called open cycle, is one of the most commonly used power cycles in bipropellant liquid rocket engines.
The YF-75 is a liquid cryogenic rocket engine burning liquid hydrogen and liquid oxygen in a gas generator cycle. It is China's second generation of cryogenic propellant engine, after the YF-73, which it replaced. It is used in a dual engine mount in the H-18 third stage of the Long March 3A, Long March 3B and Long March 3C launch vehicles. Within the mount, each engine can gimbal individually to enable thrust vectoring control. The engine also heats hydrogen and helium to pressurize the stage tanks and can control the mixture ratio to optimize propellant consumption.
A cryogenic rocket engine is a rocket engine that uses a cryogenic fuel and oxidizer; that is, both its fuel and oxidizer are gases which have been liquefied and are stored at very low temperatures. These highly efficient engines were first flown on the US Atlas-Centaur and were one of the main factors of NASA's success in reaching the Moon by the Saturn V rocket.
Rocketdyne's E-1 was a liquid propellant rocket engine originally built as a backup design for the Titan I missile. While it was being developed, Heinz-Hermann Koelle at the Army Ballistic Missile Agency (ABMA) selected it as the primary engine for the rocket that would emerge as the Saturn I. In the end, the Titan went ahead with its primary engine, and the Saturn team decided to use the lower-thrust H-1 in order to speed development. The E-1 project was cancelled in 1959, but Rocketdyne's success with the design gave NASA confidence in Rocketdyne's ability to deliver the much larger F-1, which powered the first stage of the Saturn V missions to the Moon.
The LR87 was an American liquid-propellant rocket engine used on the first stages of Titan intercontinental ballistic missiles and launch vehicles. Composed of twin motors with separate combustion chambers and turbopump machinery, it is considered a single unit and was never flown as a single combustion chamber engine or designed for this. The LR87 first flew in 1959.
Fastrac was a turbo pump-fed, liquid rocket engine. The engine was designed by NASA as part of the low cost X-34 Reusable Launch Vehicle (RLV) and as part of the Low Cost Booster Technology project. This engine was later known as the MC-1 engine when it was merged into the X-34 project.
The HG-3 was a liquid-fuel cryogenic rocket engine which was designed for use on the upper stages of Saturn rockets in the post-Apollo era. Designed in the United States by Rocketdyne, the HG-3 was to have burned cryogenic liquid hydrogen and liquid oxygen propellants, with each engine producing 1,400.7 kN (315,000 lbf) of thrust during flight. The engine was designed to produce a specific impulse (Isp) of 451 seconds (4.42 km/s) in a vacuum, or 280 seconds (2.7 km/s) at sea level.
The LR91 was an American liquid-propellant rocket engine, which was used on the second stages of Titan intercontinental ballistic missiles and launch vehicles. While the original version - the LR91-3 - ran on RP-1/LOX (as did the companion LR87-3) on the Titan I, the models that propelled the Titan II and later were switched to Aerozine 50/N2O4.
The Rocketdyne LR89 was a liquid-fueled rocket engine developed in the 1950s by Rocketdyne, a division of North American Aviation. It was designed to serve as a booster engine the Atlas rocket family. The LR89 was a liquid oxygen (LOX) and RP-1 (kerosene) engine.