General Mills Aeronautical Lab research engineers James A. Winker, Fletcher L. Bartholomew, MIT meteorologist/engineer and former AF pilot, & Richard J. Reilly, private pilot with degree in aeronautical engineering and supersonic aerodynamics.
During tracking of Project Grab Bag 79' long tear drop shaped Skyhook balloon at 73,000' to 74,000', about 40 miles away, if at about 20º to 25º elevation, a 40' to 50' object was spotted, appearing to be over Ft. Snelling, 12 to 14 miles SE of observers, at about 130º to 140º azimuth, 23º to 25º elevation, about 5º below balloon, leaving vapor or smoke trail.
Object traveling S in horizontal flight 10º in 9 seconds at about 40,000' to 50,000' altitude, roughly 900 to 1,100 mph, passed below the sun at 31º to 32º elevation, 148º to 149º azimuth.
Object left white vapor trail that immediately dissipated so as to keep constant 5º to 8º length during travel of emitting object. Went into dangerous vertical dive at about 175º-180º, or 160º-170º, azimuth for about 10 or 15 seconds dropping about 10º to about 15º to 20º, or 18ºor 20º elevation, object leveled out in a curve 3ºto 5º azimuth back to the left and vapor trail ceased to be emitted, then object glowed or flashed in the sun 2 or 3 times for 1 second each as if metallic and reflective, seen as a gray mass in the theodolite.
Disappeared suddenly with flash of light. Angular size about same as Grab Bag balloon that was about 40 miles away, thus about 1.3 arcmins.