Triethylborane (TEB) ((C₂H₅)₃B) is a chemical igniter propellant used as a igniter fluid. Storable in sealed containers; pyrophoric in air. Typical ISP: N/A (used only for ignition) seconds.
Triethylborane (TEB) is a pyrophoric organometallic compound used as a chemical igniter in rocket engines. When injected into the combustion chamber, TEB spontaneously ignites on contact with air/oxygen, providing reliable ignition of the main propellants. SpaceX’s Merlin and Raptor engines use TEB for ignition, with a limited supply allowing a set number of restarts.
Used by the SR-71 Blackbird’s J58 engines for ignition. Adopted by SpaceX for Merlin and later Raptor engine ignition systems.
Reliable ignition, simple injection system, proven in flight
Limited supply per mission constrains restarts, pyrophoric handling, produces boric acid residue
