Arc-commutated launcher

Arc-commutated launchers are a new type of linear electric motor being investigated by the electromagnetic acceleration group at M.I.T. The most promising is a coaxial discrete coil accelerator that uses the motion of the projectile itself to break down a linear array of gap switches via vapor arcing. The switches connect individual coils to a distributed energy source producing a traveling magnetic wave that is literally mechanically synchronized to the projectile position. This manner of switching is potentially much faster and certainly lighter and cheaper than conventional SCR switching. Since an arc is the only required electrical connection to the projectile, no sliding contacts are necessary. The projectile being guided by the magnetic field can ultimately achieve very high velocities (greater than 10 km/s).