Electric ignition for conductive fuels

The design and operational environment of the engines in today's jets, rockets, and missiles have raised new problems in the field of ignition. In the jet engine, the ignition must function at both high and low altitudes. At greater altitudes higher energies are required to offset decrease in oxygen: Higher energies naturally mean larger and heavier units, but size and weight are critical design factors which are strictly limited by engine specifications. In rocket and missile engines the problem is rendered more acute by the use of nitric acid or other agents which make the fuel electrically conductive. Conventional high-voltage ignition systems with jump-gap plugs are not adaptable to these fuels.