Earlier quoted context omitted.
> The object, which the U.S. learned about on Thursday evening, was described as "roughly the size of a small car," Kirby said.
A high school project could definitely launch a car sized balloon.
Working hypothese 2: The Chinese shaped the balloon as a d*ck so it appears blurred in all videos and nobody can figure out what is that, or describe its shape. Invisible ninja genius move.