Update: The failed launch has been confirmed as a Russian Bulava missile test.
First, there was a navigation warning issued for the area indicating that no one (let me repeat NO ONE) was trying to hide the fact that there was a launch test being performed. Second, another picture has emerged of the event:
The inset clearly shows a perfectly normal launch trail leading up to the more bizarre imagery that we have seen. This white trail has begun to dissipate, with differing winds at different altitudes pushing the trail around until it looks irregularly jagged. Anyone who has seen a successful launch on a clear day will recognize that trail.
At the top of the trail, there is a brighter spot and the trail itself ends abruptly. I suspect this is where the anomaly likely occurred. Having seen this picture, I will revise my earlier statements and say that the upward thrust probably ceased at this point. The remainder of the upward motion was simply from the rocket’s momentum. The blue trail is likely fuel venting from the first stage.
At the end of the blue trail, something changes. It could be that a second stage on the rocket ignited autonomously (most launches are run by an onboard script…you don’t want to have to try to command something that complex by hand), or simply that the torque got too large and created venting as I suggested before. Either way, the rotation had already been imparted to the system. Once there was some sort of thrust (engine firing, massive venting) the spiral started to form.
Anyone who says the system should have fallen to earth at that point needs to play with those spiral fireworks for a little bit. The push given by the tangential thrust may very well have kept the system rotating in what is a nearly stationary position. From some of the images the cloud is obviously three-dimensional. However it is clear that by the time the spiral started, very little of the rocket’s original forward momentum remained.