MARS-EARTH RAPID INTERPLANETARY TETHER TRANSPORT (MERITT) SYSTEM: I. Initial Feasibility Analysis
Dr. Robert L. Forward
And
Gerald D. Nordley
Routine travel to and from Mars demands an efficient, rapid, low cost means of two-way transportation. To answer this need, we have invented a system of two rotating tethers in highly elliptical orbits about each planet. At Earth, a payload is picked up near periapsis and tossed a half-rotation later, still near periapsis, at a velocity sufficient to send the payload on a high-speed trajectory to Mars. At Mars, it is caught near periapsis and is released a short time later on a suborbital reentry trajectory. The system works in both directions and is reusable. Kinetic energy lost by the throwing tethers can be restored either by catching incoming payloads or by propellantless tether propulsion methods. Tethers with tip velocities of 2.5 km per second can send payloads to Mars in as little as 90 days if aerobraking is used at Mars. Tether-to-tether transfers without aerobraking may be accomplished in about 130 to 160 days. Tether systems using commercially available tether materials at reasonable safety factors can be as little as 15 times the mass of the payload being handled. This is a relatively new concept and tasks needing further study are listed in the final section of the paper.