The tether systems I've proposed (someone else did the heavy lifting in dynamics, which is not my strong suit) involve folding extendible "truss" systems, similar to those used to extend instruments in space.
Heavier than simple tension lines, and still has some dynamics problems, but a lot more stable.
The ideal is a long, rigid truss, assembled in space from components. More stable, and even allows for a little "car" or something to move from one end to the other (assuming one end isn't just a counterweight full of propellant or something.) Active balancing systems, weights on tracks along the truss, also become practical.
Basically, a space station that's a dumbbell instead of a wheel.
Space/Science » in reply to Larry J pointed out the major problems
tethers and trusses
