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About 170 different propellants made of liquid fuel have been tested, excluding minor changes to a specific propellant such as propellant additives, corrosion inhibitors, or stabilizers. In the U.S. alone at least 25 different propellant combinations have been flown. [2] Many factors go into choosing a propellant for a liquid-propellant 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 combustion products have high specific impulse (I sp). This allows the volume of the propellant tanks to be ...
The rocket is launched using liquid hydrogen and liquid oxygen cryogenic propellants. Rocket propellant is used as reaction mass ejected from a rocket engine to produce thrust . The energy required can either come from the propellants themselves, as with a chemical rocket , or from an external source, as with ion engines .
These cryogenic temperatures vary depending on the propellant, with liquid oxygen existing below −183 °C (−297.4 °F; 90.1 K) and liquid hydrogen below −253 °C (−423.4 °F; 20.1 K). Since one or more of the propellants is in the liquid phase, all cryogenic rocket engines are by definition liquid-propellant rocket engines. [2]
Liquid propellants provide greater propulsive thrust and power, but require more complex technology and extra weight. Solid fuel is dense and burns quite quickly, generating thrust over a short time.
Hybrid-propellant rockets use a combination of solid and liquid propellant, typically involving a liquid oxidizer being pumped through a hollow cylinder of solid fuel. All current spacecraft use conventional chemical rockets (solid-fuel or liquid bipropellant) for launch, though some [note 3] have used air-breathing engines on their first stage ...
A liquid air cycle engine uses liquid hydrogen (LH2) fuel to liquefy the air. In a liquid oxygen /liquid hydrogen rocket , the liquid oxygen (LOX) needed for combustion is the majority of the weight of the spacecraft on lift-off, so if some of this can be collected from the air on the way, it might dramatically lower the take-off weight of the ...
Nitrous oxide fuel blend propellants are a class of liquid rocket propellants that were intended in the early 2010s to be able to replace hydrazine as the standard storable rocket propellent in some applications. In nitrous-oxide fuel blends, the fuel and oxidizer are blended and stored; this is sometimes referred to as a mixed monopropellant.