Vessel

Any controllable craft created by the player can be referred to as a vessel. The term usually refers to a spacecraft, in which the terms "rocket" and "spaceship" may also be used.

Spacecraft
A spacecraft is any vessel that is capable of spaceflight. Any flying vessel usually has the following attached: A pilot seat is the only part that is truly necessary, as liftoff and orbit can be achieved using the jetpack.
 * Fuel tanks
 * Engines
 * Wings
 * A pilot seat