A spacecraft specifically adapted for launch from a reusable launch vehicle such as the space shuttle by means of a cradle having locking and ejection mechanisms mounted therein. The cradle fastens into the payload bay of the space shuttle and returns therewith for reuse in subsequent launches. The spacecraft mounts at three points to the cradle, and the cradle mounts at three points to the shuttle such that a plane through the attachment points passes through the roll axis of the spacecraft at approximately the center of mass thereof. The cradle utilizes the truss structure of the spacecraft to produce the required stiffness by providing a structural tie between the two ends and the bottom of the cradle. At launch, the spacecraft is ejected with both linear and angular momentum, the spin providing gyroscopic stability. The locking mechanisms in the cradle can be remotely controlled to relock the spacecraft to the cradle in the event of an unsuccessful deployment attempt. The spacecraft includes a safety circuit employing acceleration sensing switches which sense spin-up of the spacecraft and prevent premature ignition of the perigee boost motor. The spacecraft has imbedded within its envelope a solid-propellant perigee boost motor surrounded by a liquid-propellant apogee motor. By employing apogee and perigee propulsion stages internal to the spacecraft, the storage length in the space shuttle is minimized, and the geometry and mass characteristics of the spacecraft make for a stable spinning vehicle during both the perigee and apogee boost phases.