Luminescent disk traveling at fantastic speed over ocean near Schofield barracks, Hawaii

This sighting occurred in 1967.  
While participating in jungle training in preparation for shipment to Vietnam, a fellow soldier and myself were on a hillside overlooking the ocean.  We were relaxing after a strenuous day of training.  It was about 2100 hrs and was dark.  
A silver disk streaked from the South to the North horizon in just a few seconds.  It glowed with a brillant white light.  It was about the size of nickel held at arms length.  There was no sound; also there was no tail such as a meteor might make. 
Being an amateur astronomer as well as a science teacher I was and am familiar with sightings of satellites, comets, meteors, etc.  My experience in the military also familiarized me with missles, and aircraft.
Witness indicates that the date of the incident is approximate.  PD