Sling-on-a-ring: A realizable space elevator to leo?

Abstract

In this paper, we propose a new concept of a rotovator based space elevator system called "sling-on-a-ring�". The system would consist of a high-tensile-strength equatorial circum-terra conductive fiber, associated solar-power and station-keeping units and a rotating sling module. The long sling assembly would rotate through the ring-bound mass-lifter module and would periodically descend into the atmosphere (13 km). The system would be adjusted so that at perigee, when the sling penetrates into the atmosphere, the rotational tip velocity of the sling end would almost cancel out the orbital velocity of the circum-terra ring relative to the earth's surface. With split-second timing, thepayload would be attached from an ordinary aircraft (at as low as-40000 feet) and jerked into space by the momentum of the sling. An improved version of the system (2-stage sling system) and man-rating aspects have also been discussed in the paper. Through the paper, it is intended to establish that with the availability of stronger materials, the improved version of the proposed system would be comparable to the HASTOL (in terms of tether-to-payload mass ratio), eliminating the need for hypersonic airplanes.