Electromagnetic Launch to Space

Many advances in electromagnetic (EM) propulsion technology have occurred in recent years. Linear motor technology for low-velocity and high-mass applications is being developed for naval catapults and missile launchers. Such technology could serve as the basis for the launch of a first-stage booster launch - for example, as suggested some years ago by the US National Aeronautics and Space Administration (NASA) in the Maglifter concept. For higher velocities, experimental laboratory railguns have demonstrated launch velocities of 2-3 km/s and muzzle energies greater than 10 MJ. The extension of this technology to the muzzle velocities (>= 7500 m/s) and energies (hundreds of megajoules) needed for the direct launch of payloads into orbit is very challenging but may not be impossible. For launch to orbit, long launchers (> 1000 m) would need to operate at accelerations > 1000 G to reach the required velocities, so it would only be possible to launch rugged payloads, such as fuel, water, and material. This paper provides an overview of these concepts and includes a summary of the recent advances made in this area.