A Diver Operated Plug DOP is lowered into the water during a test of the unmanned robotic submersible recovery system known as Max Rover.

As scuba divers stand by, a Diver Operated Plug (DOP) is lowered into the water at the Trident Pier at Port Canaveral during a test of the unmanned robotic submersible recovery system, known as Max Rover. Kennedy Space Center's solid rocket booster (SRB) retrieval team and Advanced Systems Development laboratory staff hope that the new robotic technology will make the process of inserting the plug into spent SRBs safer and less strenuous. Currently, scuba divers manually insert the DOP into the aft nozzle of a jettisoned SRB 60 to 70 feet below the surface of the Atlantic Ocean. After the plug is installed, water is pumped out of the booster allowing it to float horizontally. It is then towed back to Hangar AF at Cape Canaveral Air Station for refurbishment. Deep Sea Systems of Falmouth, Mass., built the submersible for NASA