Mass driver reaction engine characteristics and performance in earth orbital transfer missions

Abstract

The mass driver reaction engine (MDRE) can be used for the transfer of large payloads (hundreds to thousands of tons or more) between low Earth orbit (LEO) and geosynchronous orbit (GEO) or beyond. The mass driver is a device for converting electric energy into kinetic energy of motion of reaction mass. It consists of an accelerator/decelerator and a number of buckets. Each bucket has a cavity to contain a payload (reaction mass), and has one or more superconducting coils, but no moving parts. The reaction mass can be virtually any liquid or solid material, in any physical form. The machine could accelerate, for example, liquid oxygen, powdered metal recovered in orbit from surplus Shuttle external tanks, or raw lunar soil. The reaction mass and exhaust velocity can be chosen so that this effluent will have minimal effects in terms of leaving debris in orbit or disturbing the Earth's ionosphere. Preliminary configurations of a typical MDRE are presented. The LEO to GEO cargo orbit transfer mission events are outlined. Basic rocket equations are developed for LEO to GEO round-trip missions using a single exhaust velocity. Delivered payload, reaction mass, trip time, reaction mass flow rate, and power required are presented for different missions, specific power plant masses and efficiencies. Reaction mass trajectories, debris hazard, and effects on the Earth's ionosphere are discussed in terms of different thrusting strategies.