25.88N 89.56W (Gulf of Mexico), June 1963June 1963

On June 11, 1963, the British cargo ship M.V. Box Hill spotted something unusual in the Gulf of Mexico about 450 miles south-southeast of the Louisiana coast. The ship's crew saw what they believed was a satellite of magnitude 2.0 (a measure of brightness) rising over the horizon in the early morning darkness. Between 0700 and 0710 local time, the object moved across the sky from east-northeast to east, finally disappearing behind clouds. The observation lasted roughly 10 minutes and was made under clear skies with moonlight.

A U.S. Naval Oceanographic Office report filed June 11, 1963, forwarded the ship's sighting to NASA and the Air Force. The Smithsonian Astrophysical Observatory quickly provided predictions for the orbits of satellites in view that date, including ECHO I, a large communications satellite then in orbit. The sky conditions, timing, brightness, and trajectory all matched predictions for ECHO I passing over that location. The satellite had crossed the equator at 175.30 degrees west just a day earlier, on its regular orbital path.

Air Force investigators classified the case under Project Blue Book but found nothing unusual. The file notes make clear that the ship's crew had reported a satellite sighting, not a UFO. No investigation appears to have been needed beyond confirming that ECHO I was visible from the location at that time. The full case file as held by the National Archives spans 26 scanned pages.