Under the "BIG SAFARI" program name, RC-135Vs were upgraded from the RC-135C "Big Team" configuration. RC-135Ws were originally delivered as C-135B transports, and most were modified from RC-135Ms. This is the only difference between the V and W variants; both carry the same mission equipment. For many years, the RC-135V/W could be identified by the four large disc-capped MUCELS antennas forward, four somewhat smaller blade antennae aft and myriad of smaller underside antennas. Baseline 8 Rivet Joints (in the 2000s) introduced the first major change to the external RC-135V/W configuration replacing the MUCELS antennas with plain blade antennas. The configuration of smaller underside antennas was also changed significantly.