Sortie is a term for deployment or dispatch of one military unit, be it an aircraft

Aircraft

An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...

, ship

Ship

Since the end of the age of sail a ship has been any large buoyant marine vessel. Ships are generally distinguished from boats based on size and cargo or passenger capacity. Ships are used on lakes, seas, and rivers for a variety of activities, such as the transport of people or goods, fishing,...

, or troops from a strongpoint. The sortie, whether by one or more aircraft or vessels, usually has a specific mission

Military operation

Military operation is the coordinated military actions of a state in response to a developing situation. These actions are designed as a military plan to resolve the situation in the state's favor. Operations may be of combat or non-combat types, and are referred to by a code name for the purpose...

.

The term has been adopted from the French past participle 3rd group verb, verbs ending in -ir, with the gerund ending in -ant, "sortir", "to leave" or "to go out" with a specific purpose.

Siege warfare

In siege warfare, a sortie, or sudden issuing of troops against the enemy from a defensive position, can be launched against the besiegers by the defenders. If the sortie is through a sally port

Sally port

The primary modern meaning for sally port is a secure, controlled entryway, as at a fortification or a prison. The entrance is usually protected in some way, such as with a fixed wall blocking the door which must be circumvented before entering, but which prevents direct enemy fire from a distance...

, either to sortie or to sally can be used.

Military aviation

In military aviation

Military aviation

Military aviation is the use of aircraft and other flying machines for the purposes of conducting or enabling warfare, including national airlift capacity to provide logistical supply to forces stationed in a theater or along a front. Air power includes the national means of conducting such...

, it is used to indicate the total usages of individual machines, so that (for example) one mission involving six aircraft would tally six sorties.

The use of the term for military aircraft originated in naval

Navy

A navy is the branch of a nation's armed forces principally designated for naval and amphibious warfare; namely, lake- or ocean-borne combat operations and related functions...

 usage. In French

French language

French is a Romance language spoken as a first language in France, the Romandy region in Switzerland, Wallonia and Brussels in Belgium, Monaco, the regions of Quebec and Acadia in Canada, and by various communities elsewhere. Second-language speakers of French are distributed throughout many parts...

, sortie literally means "exit". It has come to mean a combat mission, starting when the aircraft takes off and ending on its return.

Naval evacuations

In naval terms it can also be used to describe a full-scale evacuation

Emergency evacuation

Emergency evacuation is the immediate and rapid movement of people away from the threat or actual occurrence of a hazard. Examples range from the small scale evacuation of a building due to a bomb threat or fire to the large scale evacuation of a district because of a flood, bombardment or...

 of a fleet of ships, their accompanying aircraft and submarines from a posting in advance to avoid a natural disaster

Natural disaster

A natural disaster is the effect of a natural hazard . It leads to financial, environmental or human losses...

 such as a hurricane.

Spaceflight

In spaceflight, especially for NASA

NASA

The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...

's Constellation Program

Project Constellation

Constellation Program is a human spaceflight program within NASA, the space agency of the United States. The stated goals of the program were to gain significant experience in operating away from Earth's environment, develop technologies needed for opening the space frontier, and conduct...

, the term sortie has been used for a flight of the Orion spacecraft beyond the confluence of low-Earth orbit, such as a flight to the Moon

Moon

The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...

 or to the Sun-Earth L₂ Lagrange Point. This term was not used by NASA for the nine Apollo

Project Apollo

The Apollo program was the spaceflight effort carried out by the United States' National Aeronautics and Space Administration , that landed the first humans on Earth's Moon. Conceived during the Presidency of Dwight D. Eisenhower, Apollo began in earnest after President John F...

flights that flew by, orbited, or landed on the Moon between 1968 and 1972.