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 has a lower
specific impulse than
liquid hydrogen (LH2), but is cheaper, stable at room temperature, far less of an explosion hazard, and far denser. RP-1 is significantly more powerful than LH2 by volume. RP-1 also has a fraction of the
toxicity and
carcinogenic hazards of
hydrazine, another room-temperature liquid fuel.
