Ejection Timer Circuit

Below is the design for my prototype ejection timer. It uses an NE555 timer for the delay and an N channel MOSFET to do the switching. Powering this circuit is a 9v alkaline battery. The master switch is switched on right before launch. At that point the circuit is powered but the parachute delay is not yet triggered. The break-wire  will serve that purpose. It is this break-wire that will be broken during launch. This can be done by hooking something grounded to the launchpad and the exposed vreak-wire on the fuselage. As soon as the rocket leaves the pad the wire breaks and the countdown begins.

12 seconds deployment timer