Problems of control flexibility and reliability in theory of on-board terminal systems

The paper is concerned with the specifics of terminal control problems which arise in the process of space technology evolution. The basic features of the new generation of terminal systems are identified which are their multi-purpose and multimode nature and long active life. The problem of control flexibility in theory of such systems is noted and some ways of its solution are indicated whereby motion paths, generated a posteriori, are used; the requirement is made that the system should be easily readjustible to new goals, and control algorithms of multimode systems change during the mission.
Control reliability is considered which is understood as the ability of control algorithms to preserve an acceptable performance with single failures in hardware elements. Certain ways are described to design terminal systems which improve control reliability.