Flight Control

Flight Control 

of spacecraft, the set of processes and operations that ensure the fulfillment of the objectives, missions, and programs of spacecraft flights. Flight control is directed both operationally and technically by flight control centers. Ground-based equipment and services for flight control are usually concentrated at ground control and instrumentation complexes. The operation of various flight control centers and ground control and instrumentation complexes is coordinated by coordination computer centers and by the planning and coordination services of ground control and instrumentation complexes.

Spacecraft flight control has several major tasks. These include the formulation of routine programs (for example, orbital, sessional, and daily programs) and control commands, the transmission of such programs and commands to a spacecraft, the monitoring of the transmission and execution of the programs and commands, and the updating of mission objectives and programs during a flight. Flight control also entails the periodic measurement of the spacecraft’s motion, the determination and—if, necessary—the adjustment of orbital parameters, and the remote monitoring and diagnosis of the condition of the spacecraft. Remote monitoring and diagnosis encompasses the routine telemetering of the condition and operation of onboard units, instruments, and systems, as well as the disconnection of defective or burned-out devices and the changing over to redundant systems. An important task of flight control is the maintenance of a spacecraft’s efficiency, a task that includes ensuring the maximum service life of the spacecraft and optimum operating conditions of onboard devices, the efficient consumption of power supplies, and the replenishment of power supplies. Flight control also provides for routine telephone, telegraph, and television communications, together with efficient information storage, the timely and complete transmission of information from the spacecraft to earth, and the execution of the set of operations for the return of reentry vehicles. Such operations include the tracking of a reentry vehicle, the landing of the vehicle in a given area, and the determination of the landing site. Finally, flight control permits interaction with special ground-based complexes, such as search and rescue complexes and satellite communication complexes.

Flight control is implemented, for example, when many spacecraft of various types and intended for different purposes are in space and are constantly changing their relative positions, when ground control equipment and communication channels are overloaded, when codes and frequencies are limited, or when unforeseen situations arise. The efficiency of flight control depends to a great extent on the optimum distribution of functions between onboard and ground-based equipment or, for manned spacecraft, between the cosmonaut crews and ground-based services. Optimum flight control makes it possible to achieve or even exceed the guaranteed service life of a spacecraft and to determine the amount, quality, and value of the information acquired, that is, to determine the effectiveness of the equipment used in space flight.

A. A. BOL’SHOI