The S400 is a family of pressure fed

liquid Liquid is a state of matter with a definite volume but no fixed shape. Liquids adapt to the shape of their container and are nearly incompressible, maintaining their volume even under pressure. The density of a liquid is usually close to th ...

propelled

rocket engines A rocket engine is a reaction engine, producing thrust in accordance with Newton's third law by ejecting reaction mass rearward, usually a high-speed Jet (fluid), jet of high-temperature gas produced by the combustion of rocket propellants stor ...

manufactured by

ArianeGroup ArianeGroup (formerly Airbus Safran Launchers) is an aerospace company based in France. A joint venture between Airbus and Safran, the company was founded in 2015 and is headquartered in Issy-les-Moulineaux near Paris. It consists of three core ...

(former Airbus DS) at the Orbital Propulsion Centre in Lampoldshausen, Germany. They burn MMH and MON as

propellant A propellant (or propellent) is a mass that is expelled or expanded in such a way as to create a thrust or another motive force in accordance with Newton's third law of motion, and "propel" a vehicle, projectile, or fluid payload. In vehicle ...

, have a thrust range between and and can vary the O/F ratio between 1.50 and 1.80. The chamber and throat are made of a

platinum Platinum is a chemical element; it has Symbol (chemistry), symbol Pt and atomic number 78. It is a density, dense, malleable, ductility, ductile, highly unreactive, precious metal, precious, silverish-white transition metal. Its name origina ...

alloy An alloy is a mixture of chemical elements of which in most cases at least one is a metal, metallic element, although it is also sometimes used for mixtures of elements; herein only metallic alloys are described. Metallic alloys often have prop ...

, which uses double cone vortex injectors and uses both

film A film, also known as a movie or motion picture, is a work of visual art that simulates experiences and otherwise communicates ideas, stories, perceptions, emotions, or atmosphere through the use of moving images that are generally, sinc ...

and

radiative cooling In the study of heat transfer, radiative cooling is the process by which a body loses heat by thermal radiation. As Planck's law describes, every physical body spontaneously and continuously emits electromagnetic radiation. Radiative cooling has b ...

. The S400 engines are used as primary apogee engines for telecommunication satellite platforms such as the Spacebus of

Thales Alenia Space Thales Alenia Space () is a joint venture between the French technology corporation Thales Group (67%) and Italian defense conglomerate Leonardo (company), Leonardo (33%). The company is headquartered in Cannes, France. It provides space-based ...

as well as space exploration missions such as Venus Express,

ExoMars Trace Gas Orbiter The ExoMars Trace Gas Orbiter (TGO or ExoMars Orbiter) is a collaborative project between the European Space Agency (ESA) and the Russian Roscosmos agency that sent an atmospheric research orbiter and the ''Schiaparelli'' demonstration lande ...

Jupiter Icy Moons Explorer The Jupiter Icy Moons Explorer (Juice, formerly JUICE) is an interplanetary spacecraft on its way to orbit and study three icy moons of Jupiter (planet), Jupiter: Ganymede (moon), Ganymede, Callisto (moon), Callisto, and Europa (moon), Europa ...

. The S400 family has had an extensive history in the commercial telecommunication market. Its first launch was aboard the Symphonie 1 in 1974. This was the first commercial three-axis stabilized

communications satellite A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via a Transponder (satellite communications), transponder; it creates a communication channel between a source transmitter and a Rad ...

geostationary orbit A geostationary orbit, also referred to as a geosynchronous equatorial orbit''Geostationary orbit'' and ''Geosynchronous (equatorial) orbit'' are used somewhat interchangeably in sources. (GEO), is a circular orbit, circular geosynchronous or ...

with a

bipropellant 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 combusti ...

propulsion system. It also was the first European communications satellite system. This family of engines have displayed a remarkable competitiveness, still winning many designs (for 2015, it is expected to fly on Sicral 2, ARSAT-2, Hispasat AG1 and MSG-4.

References

Rocket engines using hypergolic propellant Rocket engines using the pressure-fed cycle {{Rocket-stub