Abstract: A toroidal circumferentially wound superconducting coil is provided for generating a constant magnetic field with a significant radial field component. A room-temperature resistive coil wound circumferentially and connected to launch activating means is coaxial with the superconductive coil. Interaction of the current in the resistive coil with the radial field component of the superconductive coil produces an axial force on the resistive coil and in turn on the launch activating means. The axial force is controllable in magnitude and direction by controlling the magnitude and direction of the current supplied to the resistive coil.