It was the perception of some of the witnesses that the fiery streak ascended. Not all. Fred Meyer, for example, perceived it to be nearly horizontal but "gradually descending", as dramatized in his own press graphic.
It was the perception of some of the witnesses that the fiery streak ascended. Not all. Fred Meyer, for example, perceived it to be nearly horizontal but "gradually descending", as dramatized in his own press graphic.
About a hundred people saw the streak rise from the surface. Cargo doors don't do that.
The diagram you provided is a picture. In two dimensions. It is impossible to rule out a given 3-D trajectory based on a single 2-D rendition. For example a plane flying directly overhead, passing through the exact zenith, can only "decend" towards the horizon after passing the zenith, no matter which direction it flies, since you can't get any higher than straight up. This is even true if the plane is gaining altitude as it flies - it will still be flying towards the horizon, "down," after passing the zenith.
It's an elementary consequence of perspective.
If you really wanted to know what the full 3D trajectory of the streak was, you would combine multiple witness accounts, complete with bearing lines and so forth, and plot out what the entire 3D trajectory had to be, in order that each individual witness saw what they saw, from where they were.
But for some reason, neither the NTSB nor the FBI seemed interested in doing this. Why do you suppose that is?
In fact, only Goddard and Donaldson seemed to have taken any interest in this; they made such plots but the FBI and NTSB didn't. Why do you suppose that is?