Photo: JP Moore 1956

NIKE AJAX MISSILE LAUNCH

When the Missile Tracking Radar sends the launch command, the solid propellant booster on the missile ignites and the missile is almost supersonic before it leaves the rail where it had rested. Going nearly straight up, the booster rams the missile to an altitude of 60,000 to 70,000 feet. Then the booster burns out, its job finished. Aerodynamic drag causes it to slow and fall away, and as it does it pulls an arming lanyard that is attached to the missile, igniting its sustainer engine.

The missile’s hypergolic propellants, inhibited red fuming nitric acid (IRFNA) and aniline (later changed to Unsymmetrical Dimethyl Hydrazine or, thankfully, UDMH, combine explosively, igniting the sustainer motor’s fire. Then JP-4 jet fuel replaces the aniline as fuel, hurling the missile downrange at over 1,600 MPH. Guided by commands from the radar, the missile dives toward a point in space where it will detonate slightly above the target, spraying it with lethal shrapnel. It is not unusual for the missile to actually impact the target. This entire sequence lasts only about one minute. If there are more targets, the process is repeated.