Mass drivers need no physical contact between moving parts because they guide their projectiles by dynamic magnetic levitation, allowing extreme reusability in the case of solid-state power switching, and a functional life of – theoretically – up to millions of launches. While marginal costs tend to be accordingly low, initial development and construction costs are highly dependent on performance, especially the intended mass, acceleration, and velocity of projectiles. For instance, while Gerard O'Neill built his first mass driver in 1976–1977 with a $2000 budget, a short test model firing a projectile at 40 m/s and 33 g,Compare: his next model had an order-of-magnitude greater accelerationCompare: after a comparable increase in funding, and, a few years later, researchers at the University of Texas estimated that a mass driver firing a 10 kilogram projectile at 6000 m/s would cost $47 million.IEEE Transactions on Magnetics, Vol Mag-18, No. 1, January 1982. Retrieved May 10, 2011.Electromagnetic Launchers for Space Applications. Retrieved May 10, 2011.
Mass drivers need no physical contact between moving parts because they guide their projectiles by dynamic magnetic levitation, allowing extreme reusability in the case of solid-state power switching, and a functional life of – theoretically – up to millions of launches. While marginal costs tend to be accordingly low, initial development and construction costs are highly dependent on performance especially the intended mass, acceleration, and velocity of projectiles. For instance, while Gerard O'Neill built his first mass driver in 1976–1977 with a $2000 budget, a short test model firing a projectile at 40 m/s and 33 g,Compare his next model had an order-of-magnitude greater accelerationCompare: after a comparable increase in funding, and, a few years later, researchers at the University of Texas estimated that a mass driver firing a 10 kilogram projectile at 6000 m/s would cost $47 million.IEEE Transactions on Magnetics, Vol Mag-18, No. 1, January 1982. Retrieved May 10, 2011.Electromagnetic Launchers for Space Applications Retrieved May 10, 2011.