Juno is a liquid bipropellant rocket engine that is the successor to Aquila, ERPL's first liquid bipropellant engine (and first engine in general). Juno will serve as a modular, experimental testbed to inform the design of future liquid rocket engines. Its propellants are liquid oxygen and ethanol. It is ablatively cooled. Its chamber pressure is 350 psi, thrust is 300 pounds, and its specific impulse is 256 seconds. It has completed manufacturing and is scheduled to be first test fired on Draco in the spring of 2024.