An
air-to-surface missile (
ASM) or
air-to-ground missile (
AGM or
ATGM) is a
missile designed to be launched from
military aircraft at targets on land or sea. There are also unpowered guided
glide bombs not considered missiles. The two most common propulsion systems for air-to-surface missiles are
rocket motors, usually with shorter range, and slower, longer-range
jet engines. Some
Soviet-designed air-to-surface missiles are powered by
ramjets, giving them both long range and high speed.