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.
About two litres of RP-1
Apollo 8, Saturn V with 810,700 litres of RP-1 and 1,311,100 liters of LOX in the S-IC first stage
Kerosene, or paraffin, is a combustible hydrocarbon liquid which is derived from petroleum. It is widely used as a fuel in aviation as well as households. Its name derives from Greek: κηρός (kērós) meaning "wax", and was registered as a trademark by Nova Scotia geologist and inventor Abraham Gesner in 1854 before evolving into a generic trademark. It is sometimes spelled kerosine in scientific and industrial usage.
A kerosene bottle, containing blue-dyed kerosene
Persian scholar Rāzi (or Rhazes) was the first to distill kerosene in the ninth century. He is depicted here in a manuscript by Gerard of Cremona.
A queue for kerosene. Moscow, Russia, 1920s
A truck delivering kerosene in Japan
