The number of countries owning spacecraft is increasing. Ownership is becoming more complex as multinational consortiums form to launch satellites in international waters. Country of ownership changes as spacecraft are bought, sold, or leased. An entire series of spacecraft may have the same name, while a single spacecraft may have several names during its lifetime. Duplicate names are beginning to appear, creating confusion.
Missions range from a very simple single, mission to complex multiple missions.
Many of today's launch vehicles started life as ICBM's in the late 50's, while other launch vehicles are just entering service. To add to the complexity, some launch vehicles have the same name as a spacecraft, while other launch vehicles may have several names or designations. Several families of launch vehicles have special designations conforming to their own naming conventions. The orbits a spacecraft uses are as varied as their names. Orbits can be as simple as a low Earth orbit or as complex as a multi-planet rendezvous lasting decades.