I missed part of the thread, but the whips are an idea of the late brilliant
Robert F. Forward. I think Tether's Inc. is still going.

The idea is that a mass orbits at a reasonable height. Two or three long whips
rotate at such a speed that if they where a wheel, it would be rolling on an
imaginary sphere that matched the globe that would fit the intended intercept
altitude. Just like the wheel of a car, at the lowest point it is not moving
with respect to the Earth. If the end is flyable, the slack or flexibility
allows it to station keep or more on some course and speed to perform the
intercept. The timing has to be good, like 20 or 30 seconds, but lining it all
up is pretty predictable.

The whip is kept powered up by delivering material from space back to Earth.

Forward worked out a series of transfer whips that would allow travel to Mars
without carrying any more than maneuvering fuel. The ship or attachment has to
be able to travel on the whip in order to change angular speed (by moving the
mass closer to or further from the release points. Or delivering the load to
the central mass.)

I can pull out his papers and elucidate if anyone wants more. We exchanged
copies of everything we had published once. I sent some letters to the editors
of journals and tech magazines. He sent a big box of Hughes Research internal
papers, patents, Omni articles, Physical Review papers, etc. (Included is the
famous "Rotating Cylinders and the Possibility of Global Causality Violation.")

Forward thought up a lot of great stuff. NASA uses his space-time flatteners
for micro-gravity research on the Shuttle. He invented the third of the four
basic instruments for testing or measuring gravity, the Rotating Gravity
Gradiometer. (I invented the fourth, which required his as a detector). We used
to talk occasionally. His death from a brain tumor in his 60's was a major
loss.

-- Charlie Springer