The heavily referenced paper assumes no new science, but is based on projections of scientifically-understood technological progress. Advanced Technologies discussions at the SSI 1995 annual meeting included presentation of four papers, including Vetter's topic discussed above. The better material you have, the more efficient tether you can have. Basically, we can probably bootstrap up a space manufacturing facility, with just a few hundred kilograms of equipment, plus a few tons of tether and ballast and some ability to do some processing at some other point, like at a low Earth orbit space station. The need for nanoscale computing devices is also clear.
Scenarios are fictional representations of alternative futures, focused on particular issues.
Private ownership of extraterrestrial real estate becomes a significant issue, and a market develops to allocate rights to carbonaceous solar system bodies that have been distributed to all adult citizens of the world. The scenario's key features are relatively slow development of molecular nanotechnology capability, and a high level of planning. Before large institutions understand what's happened, every developable asteroid in the solar system is claimed, developed, and colonized. It's a disorganized, almost anarchic path to space development, but it occurs faster and more completely than the highly-planned path. The scenario's key features are relatively fast development of molecular nanotechnology capability, and a low level of planning.