Prometheus

The Prometheus engine is Tartarus’ current subscale bipropellant liquid rocket engine. This engine is the result of an extensive project-wide rescope; it has not been designed for flight, but rather as a conservative demonstrator engine to validate simulations and test stand operations. Prometheus will employ a pressure-fed blowdown cycle, meaning the fuel and oxidizer will be pressurized via inert nitrogen gas. The engine will be machined out of copper and will utilize ethanol as its fuel and cryogenic liquid oxygen as its oxidizer. It is projected to produce an estimated 250 lbf of thrust and have a specific impulse of about 140 seconds. Seeing as chamber temperatures are predicted to reach upwards of 1200 degrees Celsius, it’s crucial to implement efficient cooling techniques into the engine’s design to ensure stable performance. The Prometheus engine will utilize both Boundary Layer Cooling (BLC) and bulk cooling for this purpose. BLC involves injecting a ring of fuel streams near the chamber walls, which effectively creates an insulating layer between the walls and the hot combustion gases. While BLC will serve as the primary cooling method, excess heat can also be removed via bulk cooling. This method essentially involves the chamber walls acting as a heat sink, where extra material surrounding the nozzle can absorb and disperse heat from combustion. Hot fire of the Prometheus demonstrator engine is slated for Spring 2025.