Moon & Mars Orbiting Spinning Tether Transport - Tethers Unlimited

Tethers Unlimited, Inc.MMOSTT Final ReportFigure 6. The Tether Boost Facility Design concept.1. 5,000 kg Payload Tether Boost FacilityThe general trend for GEO communications satellites has been for the satellites to becomelarger and larger with time. Our market projections indicate that a potential “sweet spot” forsystem payload to GTO would be around 5,000 kg. A tether system capable of delivering thissized payload to GTO could serve approximately 80% of the market projected in 2010.Consequently, the initial design effort focused on designing a tether system capable of boosting5,000 kg payloads from 300 km circular LEO to GTO. Because the tether system is a highlyreusable infrastructure, one key to achieving minimum transportation costs will be to maximizeits throughput capacity. By estimating the potential market in 2010, we concluded that areasonable throughput for which to aim would be one payload per month. Thus the systemwas designed to reboost its orbit within 30 days after each payload boost operation. The initialsystem design for this LEO⇒GTO Tether Boost Facility is described in Appendix E: “TetherBoost Facility Design Study Interim Report”.The potential launch cost savings that a Tether Boost Facility could provide to a customercan be illustrated by considering a mission to place a 5,000 kg payload in GTO. To do so usingconventional rocket systems would require a launch vehicle comparable to a Delta IVM+ (4,2),costing upwards of $90M. With a Tether Boost Facility capable of picking the payload up fromLEO and tossing it to GTO, the customer could instead use a much smaller launch vehicle suchas a Dnepr 1, with a launch cost of approximately $13M. Even when the operational costs of the9