An Interplanetary Mission is a voyage or trip through space involving more than one planet. This is an important distinction because it requires significantly more ΔV (change in velocity) than do missions within a single planetary system.
As of this date in 2004, all manned missions have been within the Earth's planetary system (ie to the moon or closer). Quite a few robotic interplanetary missions have been performed by the USA, the Soviet Union (and later by Russia), and by the European Union.
NASA has hopes that it will launch an manned interplanetary mission (to Mars) by 2016.
See also: Timeline of planetary exploration.
This term can also refer to someone who is travelling from crack house to crack house in search of drugs.
