The response of the underwater robot depends on the nature of the emergency or failure. Awareness of emergencies and failures external to the individual robot will be communicated acoustically through the USBL, and the updated desired behavior of the robot will react accordingly. For example, suppose the surface vessel becomes unavailable due to incoming weather conditions or an onboard emergency such as a fire. In that case, the communication signal will be sent to the robot to change its course or hold in place until the weather has passed or operations can be resumed in extreme cases with the second ship in the operations.
For small internal failures to the robot, such as loss of connection to certain computers or components, an isolated power reset will occur to re-establish the connection. If the error persists, the mission will abort. Other small failures, for example, could be a break to an arm, and in these cases, the robot is expected to complete the mission and have the damage repaired at the surface.
Each vehicle has a high degree of redundancy, and there are limited single points of failure. An example of a failure that will result in an aborted mission and an emergency ascent is if a leak detection sensor is triggered.
A final active emergency response if the robot is not rising to the surface due to loss of power to achieve this or for any other reason, it will release the load in the hopper; actively attempted if control electronics and power are available or triggered passively using a time delay corrosion fuse that will release the load after approximately 1.5 weeks have passed.
In all cases, a locating beacon on a separate power supply will ping to inform the surface ship of its position if the beacon loses communication with the rest of the vehicle
