Free Space Skyhooks A non-planetary Kevlar skyhook with tip
velocity wrt its center of 1/4 earth escape velocity, which is
just enough to catch a Venus-Earth Hohmann and accelerate it to
Earth-Mars Hohmann is able to support 1/425 of its mass at each
end, building in a safety factor of two. If the skyhook masses
21x10^6 Kg., it can support 50,000 Kg (about the mass of
Skylab), at each end. Considering different lengths (mass ratio
is unaffected by geometry): Skyhook Rotational Acceleration Area
of cable Area of cable radius period ends middle 100 Km 3.74 min
8 g 28 cm^2 1700 cm^2 1000 Km 37 min 0.8 g 2.8 cm^2 170 cm^2
2000 Km 1.25 hrs 0.4 g 1.4 cm^2 84 cm^2 5000 Km 3 hrs 0.16 g
0.56 cm^2 34 cm^2 10,000 Km 6.25 hrs 0.08 g 0.28 cm^2 17 cm^2
20,000 Km 12.5 hrs 0.04 g 0.14 cm^2 8.4 cm^2 The cable cross
section as a function of radius is a perfect EXP(-r^2) normal
curve. Macsyma was able to integrate it symbolically, to get an
expression for the mass ratio. The integral naturally contains
the error function. The t