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.

SpaceX manufactures launch vehicles to operate its launch provider services and to execute its various exploration goals. SpaceX currently manufactures and operates the Falcon 9 Block 5 family of medium-lift launch vehicles and the Falcon Heavy family of heavy-lift launch vehicles – both of which are powered by SpaceX Merlin engines and employ VTVL technologies to reuse the first stage. As of 2024, the company is also developing the fully reusable Starship launch system, which will replace the Falcon 9 and Falcon Heavy.