Incident #90 Sighting Report — Las Cruces, New Mexico, 29 June 1947

This document comprises a series of reports and correspondence regarding Incident #90, a sighting of an unidentified aerial object that occurred on June 29, 1947. The incident involved several witnesses, including employees of the Naval Research Laboratory (NRL) who were traveling on Highway 17 between Las Cruces, New Mexico, and the White Sands V-2 firing grounds. The witnesses, who were familiar with aircraft and meteorological balloons, reported observing a single object moving at a rapid velocity in a northerly direction. The object was described as having a uniform shape with no visible protuberances, such as wings, and was estimated to be at an altitude between 8,000 and 10,000 feet. The observation lasted approximately 30 seconds. The witnesses noted a solar specular reflection that seemed to change in intensity as the object receded from view. One witness initially thought they saw vapor trails. Major William P. Mellen of the Air Materiel Command conducted an interview with the primary witness on July 18, 1947, in the presence of the Acting Rocket Sonde Section Head. The report emphasizes that the witnesses were not intoxicated and possessed technical knowledge relevant to the observation. Despite this, the official evaluation concluded that the information provided was insufficient for a definitive identification, though it suggested the possibility that the object could have been meteoric. The document also includes broader administrative context regarding Project Grudge and Project Sign, including an appendix regarding the analysis of balloon launches, which were frequently investigated as potential explanations for such sightings. The file contains multiple iterations of the incident report, including a check-list and formal letters from the Naval Research Laboratory to the Army Air Forces.