Hobby rocketry has grown over the past few decades to include some very large and powerful rockets that weigh over 100 pounds and are over 12 feet long. These larger rockets require 1000 feet or more of distance between the launch pad and people, cars and buildings for proper safety. This requires some form of launch system capable of working over this distance. Most launch control systems use some combination of batteries, wires, switches, and relays.
Many hobby rocket club launch systems include a launch console with a bank of switches to allow the Launch Control Officer (LCO) to select which rocket(s) are to be launched, a master safety key switch, and a “big red button” to launch the rocket. At the launch pads, there are batteries and relays. The coils of the relays are driven through wires that are connected to the launch console. The relays connect to the rocket motor igniter through a pair of wires and alligator clips.
These wires are problematic for a number of reasons but there are two primary ones. First, people often trip over them and knock over some part of the launch system, sometimes damaging it. Obviously, people can fall and get hurt too. Second, even when treated with respect and care, the wires fatigue and break resulting in a frustrating day at the launch field debugging a broken launch system.
Author: Daniel Miner