Interesting photo's

Thanks for posting.
The first three images are cropped from your shots. I wanted to compare them to known images of night launches. The last two are known images of
launches from NASA.
As some one mentioned earlier the digital zoom creates issues. The first (upper) of the two known images I used a method of resizing probably similar
to what your camera does and enlarged by an equal amount to your shot. The bottom image I used a much better method of resizing to show how superior
it is to what is done inside the camera. It is generally better to enlarge in software and leave the digital zoom off.
What I did to these is use a channel mixer to remove some of the blue channel (the hottest portion of a flame) and increase the reds (the cooler
portions of a flame) to give me something to compare with the known photo's to see if we are looking at a flame or a flare. From the results you see
below I'd say what you shot is indeed from combustion.
This still does not identify what you shot other than to say it could have been a rocket of some sort or something burning up from friction. Because
the shape does not seem to match that of a rocket engine, I suspect the later.
Known launch images below-
Whatever you took these photo's of there would appear to be a great deal of heat involved.