Abstract
Mass driver Wikipedia overview. Historical milestones: 1937 Edwin Northrup ("Zero to Eighty," prototype coilguns); 1976-77 O'Neill Mass Driver 1 ($2000 budget, 40 m/s, 33 g); 1982 Mass Driver 2 (5000 m/s² nominal, 112 m/s final); 2021 SpinLaunch initial accelerator testing. Theoretical performance: "A 1 km superconducting mass driver could accelerate a 20 kg vehicle to 10.5 km/s at 80% conversion efficiency" with average 5,600 g. Earth-based to LEO: human-rated requires "almost 1000 kilometres" of track at acceptable g-forces; lightweight unmanned can reach 20+ km/s. Cost estimate: University of Texas projected "firing a 10 kilogram projectile at 6000 m/s would cost $47 million."
Key claims
- md1-1976: "1976-1977: Gerard O'Neill constructed his first mass driver on a $2,000 budget, achieving 40 m/s velocity and 33 g-force acceleration."
- md2-1982: "1982: Mass Driver Two demonstrated nominal design acceleration of 5000 m/s² with a final velocity of 112 m/s."
- superconducting-spec: "A 1 km superconducting mass driver could accelerate a 20 kg vehicle to 10.5 km/s at 80% conversion efficiency" with average 5,600 g.
- earth-track-length-human: "Earth-based systems targeting low Earth orbit would require almost 1000 kilometres of track length for human-rated payloads at acceptable g-forces."
- ut-cost-estimate: "University of Texas researchers estimated a mass driver firing a 10 kilogram projectile at 6000 m/s would cost $47 million."
- earth-to-leo-marginal-cost: "Human-crewed launches from Earth could reduce costs to under $1 of electrical energy cost per kilogram shipped to LEO."
Reviewer notes
Tier E (Wikipedia). Useful as historical anchor: Mass Driver 1 and Mass Driver 2 demonstrated actual prototype performance (40 m/s, 112 m/s) is roughly 10⁻⁴ to 10⁻² of operational lunar mass driver velocities (1.7-2.4 km/s) — a substantial extrapolation. The "1 km superconducting mass driver at 80% efficiency" claim is consistent with the 1979 NASA SP-428 96.4% efficiency claim (both reflect theoretical-ceiling drive-coil efficiency, not system-level efficiency including pulsed-power and power-supply losses). The University of Texas $47M / 10 kg / 6 km/s estimate is the most relevant academic cost projection for an Earth-based academic-scale system; scaled to a lunar 200-kg-per-shot operational system this implies very different capital. Useful for orientation; not citable as primary evidence.