Which essential task involves overseeing the movement and safety of aircraft?

The essential task associated with overseeing the movement and safety of aircraft is air traffic control. This function is critical in managing airspace to ensure that aircraft can take off, navigate, and land safely, without conflicts or accidents. Air traffic controllers coordinate the timing and sequencing of aircraft movements on the ground and in the air, providing instructions and guidance to pilots. Their responsibilities include ensuring safe distances between aircraft, monitoring aircraft positions, and facilitating communications between pilots and ground operations.

Air defense primarily focuses on the protection of airspace from hostile threats rather than the direct oversight of aircraft movement. Fire support coordination deals with the integration of fires from various support assets in conjunction with ground forces, rather than the management of aircraft traffic. Session management is often associated with network operations or the management of interactions in digital applications and does not pertain to aircraft movements or safety. Thus, air traffic control is the only option that encompasses the crucial responsibilities related to the safe movement and management of aircraft in aviation operations.