Origins
The word "mission" embodies one of the most consequential concepts in the history of world civilization: the idea that certain people are sent forth with a purpose. It entered English around 1530, initially in the context of Jesuit religious expeditions, from Latin "missiō" (a sending, a dispatching), from "missus," the past participle of "mittere" (to send, to let go, to release).
The Latin verb "mittere" is one of the most prolific root words in English. Its past participle "missus" generated an astonishing family of words: "missile" (something sent flying), "missive" (something sent, a letter), "emit" (to send out), "transmit" (to send across), "permit" (to let through), "submit" (to send under, to yield), "admit" (to send to, to allow in), "commit" (to send together, to entrust), "dismiss" (to send away), "remit" (to send back), "omit" (to let go of), and "promise" (to send forth, originally a declaration sent forward).
The religious sense of "mission" was the first to establish itself in English. The Society of Jesus (Jesuits), founded in 1540, organized systematic missions to convert non-Christians around the world. These Jesuit missions gave the word its English debut. The concept of a "missionary" — one who is sent on a mission — followed naturally and was first recorded in 1625.
Development
The Spanish missions of the Americas are among the most visible legacies of this religious usage. The 21 California missions, founded by Franciscan friars between 1769 and 1833, became so culturally significant that they spawned an entire architectural style (Mission Revival), a type of fig (the Mission fig, grown at the missions), and numerous place names. San Francisco's Mission District is named for Mission Dolores, founded in 1776.
The diplomatic sense of "mission" — a delegation sent to a foreign country — developed in the 17th century. A diplomatic mission could be temporary (a special envoy sent for negotiations) or permanent (an embassy). This usage expanded to include trade missions, scientific missions, and cultural missions.
The military sense — a specific combat operation — became prominent in the 20th century, particularly during World War II. Bomber crews flew "missions" over enemy territory. The phrase "mission accomplished" entered military vocabulary as a formal declaration that objectives had been met, though it gained ironic overtones after its controversial use on a banner during President George W. Bush's 2003 speech aboard the USS Abraham Lincoln.
Scientific Usage
The space age gave "mission" perhaps its most dramatic context. NASA's missions — from Mercury and Gemini through Apollo to the Space Shuttle and Mars rovers — made the word synonymous with organized scientific exploration. "Mission Control" in Houston became a symbol of coordinated human endeavor, and "mission specialist" became an astronaut classification.
In the corporate world, the "mission statement" emerged in the 1980s as a formal declaration of an organization's purpose and values. This usage reflects the word's etymological core: a mission statement defines what the organization has been "sent" to do, its fundamental reason for existing.
The informal sense of "mission" as any important personal task ("I'm on a mission to find the perfect pizza") shows how thoroughly the word has been domesticated from its original religious and diplomatic contexts. Yet even in casual usage, the word retains a sense of purposefulness and determination that distinguishes it from mere "task" or "errand."
Legacy
The phrase "mission creep" — the gradual expansion of a mission beyond its original objectives — entered military and political vocabulary in the 1990s, particularly in relation to peacekeeping operations. It has since been adopted by project managers, educators, and anyone whose originally focused project has spiraled into something larger than intended.