[D-fendr]

Best possibility was given via Tommyjo on a related thread. Explains the most unknowns about this event.

The above photo is a jet contrail NOT a missile. Look familiar?

Source: Jet contrails look like missile

[NonValueAdded]

Sorry but the flame signature at the flight end says rocket. Looks like everything I’ve seen take off from KSC or the Eastern test range.

[Michael Barnes]

Still does not explain the heat source that is clearly visible to the naked eye in the video. Whatever it is, it’s kicking out some thrust!!