Space operation service

A radiocommunication service concerned exclusively with the operation of spacecraft, in particular space tracking, space telemetry and space telecommand.

Space research service

A radiocommunication service in which spacecraft or other objects in space are used for scientific or technological research purposes.

Earth exploration-satellite service

A radiocommunication service between earth stations and one or more space stations, which may include links between space stations, in which:

• information relating to the characteristics of the Earth and its natural phenomena, including data relating to the state of the environment, is obtained from active sensors or passive sensors on Earth satellites;
• similar information is collected from airborne or Earth-based platforms;
• such information may be distributed to earth stations within the system concerned;
• platform interrogation may be included.

This service may also include feeder links necessary for its operation.

Space research service

 A radiocommunication service in which spacecraft or other objects in space are used for scientific or technological research purposes.

Amateur service 

A radiocommunication service for the purpose of self-training, intercommunication and technical investigations carried out by amateurs, that is, by duly authorized persons interested in radio technique solely with a personal aim and without pecuniary interest.

Amateur-satellite service

 A radiocommunication service using space stations on earth satellites for the same purposes as those of the amateur service.

More information on page 17: ITU-Radio regulations (book 1)