ATO may refer to: Technology. Abort to Orbit, an intact abort procedure for Space Shuttle launches. Arsenic trioxide a potent chemotherapeutic agent for acute promyelocytic leukemia. ATO fuse. Automatic train operation. Assisted take off. Military. Air Tasking Order, (United States Air Force) Air Training Officer, a former position at the United States Air Force Academy. Ammunition Technical Officer, a designation in several armed forces. Anti-Terrorist Operation in Ukraine, the Ukrainian government's operation in the war in Donbas (since 2018 it has been called Joint Forces Operation, JFO).
https://en.wikipedia.org/wiki/ATO