Our next opportunity finally arrived two weeks later. Having been through two “dress rehearsals,” we knew what to expect. 

The procedure was to lay out the balloon on a protective tarp on the runway.  The topmost section of the balloon, a small portion that would become the “bubble”, was fed through a retaining “spool” and folded back on itself.  The top section had two tubes, made of balloon material, through which helium would be fed, inflating the bubble, which would gradually ease up from the tarp, eventually becoming large enough to lift itself off the ground entirely, with only the spool and the tension from the uninflated remainder keeping it in place.