Answer:

mission

Answer	Crossword Clue
MISSION	Pilot's assignment
MISSION	Assignment
MISSION	Group of envoys to a foreign country.

MISSION	The Alamo, for example.
MISSION	Organization for religious work.
MISSION	Diplomatic delegation.
MISSION	"Impossible" on TV
MISSION	Task
MISSION	TV's "... Impossible"
MISSION	The Alamo, once
MISSION	Ace's assignment