The Aegis Ballistic Missile Defense System (BMD) program is intended to enable the Aegis system to act in a sea-based ballistic missile defense function, to counter short- and medium-range ballistic missiles of the variety typically employed by a number of potential opponent states.
Nel 1994 la Martin Marietta (che aveva acquisito il programma Aegis) ricevette l'incarico di adattare il sistema per conferirgli capacità TBDM (Theatre Ballistic Missile Defence) ossia la capacità di ingaggiare missili balistici.