Triple 4 is a 4 kN autogenous, ablatively cooled liquid rocket engine utilizing nitrous oxide (N₂O) and isopropyl alcohol (IPA) propellants. Designed with a strong emphasis on additive manufacturing and rapid design iteration, it is the first liquid rocket engine I have personally developed.

I was solely responsible for the design and development of the engine's fluid and combustion systems. From project inception to releasing parts for manufacturing, the complete design cycle took four weeks. A significant portion of that effort was dedicated to benchmarking against published engine designs and optimizing components for Direct Metal Laser Sintering (DMLS) manufacturing processes.

The name Triple 4 originates from the project's initial design requirements: a 4:1 oxidizer-to-fuel ratio, a quadlet injector configuration, and a 4-inch engine form factor.

Beyond serving as a standalone development program, Triple 4 establishes the design methodology, performance expectations, and system architecture that will be carried forward into the team's next liquid propulsion project, the 20 kN Triple 8 engine.