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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 ...
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 ...
Several propellants were tried in various programs: One of the later (1991) successful gun fuels was a saturated solution of ammonium perchlorate in ammonia.This has a vapor pressure of one atmosphere at 20 °C (68 °F), and generally forms a convenient liquid that is stable and possible to handle.
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.
On the other hand, if the propellants are cooled sufficiently, they exist in the liquid phase at higher density and lower pressure, simplifying tankage. 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).
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 .
The aerosol spray canister invented by USDA researchers, Lyle Goodhue and William Sullivan.. The concepts of aerosol probably go as far back as 1790. [1] The first aerosol spray can patent was granted in Oslo in 1927 to Erik Rotheim, a Norwegian chemical engineer, [1] [2] and a United States patent was granted for the invention in 1931. [3]
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