A lunar mass driver is a proposed electromagnetic launch system optimized for the Moon’s low gravity (1/6th Earth’s) and hard vacuum, consisting of a long, straight acceleration track (typically several to tens of kilometers) lined with sequentially fired superconducting coils or linear synchronous motors that propel a payload-carrying sled or bucket to lunar escape velocity (~2.38 km/s). The track is usually elevated on supports or aligned along a natural slope (e.g., crater rim) to achieve the desired trajectory. Payloads experience continuous acceleration (potentially 20-100 g for brief periods) without atmospheric drag or chemical propellant expenditure, enabling theoretically high throughput at far lower recurring cost than rockets. Practical challenges include the immense construction effort, precise alignment for orbital insertion, recoil management into the lunar surface, and the energy storage needed for rapid repetitive launches.
NASA 
