Project web site: http://www.circlemud.org/~jelson/rocket
Our rocket will have "thrusters" and an "engine" -- actually air nozzles and an air-driven paint shaker that are powered by an air compressor. We bought solenoid air valves so that the rocket panel would be able to actuate the "thrusters" and "engine". Unfortunately, the solenoids require a lot more power (6 watts) than the latches on the board can source, so I hand-built a small board that takes its own separate 12v in and switches 4 channels using 4 power MOSFETs. Inputs are low enough current that they can be driven by the latches. I threw in some LEDs for good measure.