Project 10073 Record Card and Related Correspondence — San Juan, Puerto Rico, 26 February 1960

This document collection details a series of reports regarding an aerial sighting over San Juan, Puerto Rico, on 26 February 1960. The primary report, filed under Project 10073, describes a sighting by Reginald P. Briggs, a geologist with the U.S. Department of Interior. At approximately 2302Z, Briggs observed a ball-shaped, bright red object with a yellowish-orange tinge. He described the object as being the size of a large pea held at arm's length, which left a persistent contrail for ten minutes before disappearing. The observation lasted less than one second. The report notes that four additional reports of similar activity were received from ground and air observers, who described the phenomena as pyrotechnic activities or possible missile reentry. The official evaluation by the Air Technical Intelligence Center and associated military communications concluded that the sightings were the result of a U.S. Navy surface unit conducting a night illumination training exercise. Several teletype messages included in the file corroborate the confusion surrounding the event, with various reports from the USS Tringa, FAA San Juan, and commercial pilots describing brilliant flashes, smoke trails, and fireballs. While the initial military assessment by Captain Donald K. Mangels of the 72nd Bombardment Wing considered the possibility of a satellite or missile reentry, the final consensus across the communications was that the activity was consistent with Navy illumination exercises conducted in the area between 270001Z and 270300Z. The documentation provides a comprehensive view of the reporting process for unidentified aerial phenomena during this period, highlighting the coordination between civilian observers, the FAA, and military intelligence units.