Watching what has been going on, I think I can tell this. Back in the late 1960's one of my buddies "discovered" how to make hydrogen gas, can't remember how he did it. One of the other guy's dad owned the local dry-cleaning establishment and had a roll of the plastic bags at his house. We figured to use them to make several ballons for the gas. One guy came up with the bright idea of tying several together to increase lift and then attaching one end of a long roll of aluminum foil. Being late evening when we "launched" from his back yard the sun reflected on the foil in several colors. Pretty soon it was several hundred feet up, still ascending and moving faster due to the wind.
Now comes something we hadn't figured on and I can only hope the time limit is up on what we did. Oh well, I am the only one left of my gang to tell the tale. Little did we know that people started calling the local constabulary of various colored lights traveling up in an erratic pattern and also being picked up on radar from the local airport! Jets were scrambled to track this "mysterious" craft that appeared and then disappeared later to be seen some distance as several radar's tracked the "UFO' and then it really took off into the stratosphere and went off radar.
Next morning we met at my buddy's house quite scared of what we had done inadvertently. A harmless teenage prank had snowballed into the U.S.A.F. coming to town with project Blue Book investigator to talk to the local cops and anyone else. Needless to say we kept a low profile and our parents were pleased that we just cut grass and stayed out of trouble.
Sam