Somthing is missing here
We know it couldn't take off without some form of external fuel tanks so the video might have accidentally omitted a few things. We understand flying bodies well enough to know this can work. Now I'd just like someone to explain how they'll solve the challenges we had with our previous shuttle. The public has become much more educated about this topic so now we want more specifics about how this thing could/would really work, not just cute little videos.