Follow the path of this object. It makes a greater than 90 degree turn, appearing to almost fall as it reaches its peak. If this were debris, it would need an external force to do this. Gravity's affect should not be this extreme and visible because in order for debris to be visible for such periods of time, they would have to be close and their velocity would be nearly equal to that of the shuttle's. The shuttle's thrust is not a very good explanation because there is no flash and the tether itself does not appear to accelerate. Electromagnetic forces may be the only possibility except that all of the objects, if they appear to accelerate, only will do so in the downward direction, yet electromagnetic forces would most likely not be so consistent.