>you don't necessarily need the payload itself to supply this horizontal acceleration. The space elevator is attached to the ground at one end, and the other is

>you don't necessarily need the payload itself to supply this horizontal acceleration. The space elevator is attached to the ground at one end, and the other is way up in orbit. On a conventional space elevator this is true. You just go up to 35,786 km altitude (AKA geostationary orbit) and let go. However the structure described in this paper only goes up to 200 km altitude, so it still needs a horizontal acceleration system.