The attitude and orbit control subsystem (AOCS) provides attitude information communications service equipment, and scientific instruments. Control is. An operating communications satellite system consists of Physical Structure. Attitude and Orbit Control System. (AOCS). Power System. Thermal Control. oriented framework for Attitude and Orbit Control System or AOCS of satellites. Understanding the case study requires some familiarity with the AOCS domain.

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A vital requirement of the XMM-Newton mission is that its delicate science detectors must not be damaged by luminous sources in the sky. In this method, the body of the satellite rotates around its spin axis. After this, the de-spin system operates in order to make the TTCM subsystem antennas point towards earth station. Communication subsystem is placed on top of the drum. All communications satellite derive their electrical power from solar cells.

If there is a change in altitude of the satellite, then the angles between the respective axes will be changed. On the basis of data supplied by a star-tracker telescope, which recognises the different star formations in its field of view, the AOCS computers calculate the appropriate momentum of the reaction wheels for precision manoeuvring of the spacecraft during observations or to change the target.

For redundancy XMM-Newton carries a second star-tracker telescope.

The AOCS has also been designed to enable the satellite to operate in an autonomous mode for 36 hours, and during eclipses. Satellte systems are partly on the satellite and partly at the controlling earth station. This set of three axis provides the information about orientation of the satellite with respect to reference axes.


Attitude and orbit control system AOCS. During launching phase, the satellite spins when the small radial gas jets are operated.

Two types of transponder in use: The letter use is housekeeping, since these subsystems serve to support the communications system. Following are the two methods to make the satellite that is present in an orbit as stable. Reaction wheel courtesy of MMS. Create your website today.

Based on telemetry data received from the satellite and orbital data obtained from the tracking system, the control system is used to correct the position and attitude of the satellite. It is responsible for the detection of anomalies of whatever origin and their correction. They will provide the rotation in both directions of the three axes.

A satellite which uses multiple frequency bands usually has four or more antennas. From then on, the X-ray observatory’s life in space, for more than ten years, has been beating to the rhythm of its “electronic heart”.

Satellite Communication AOC Subsystem

So, the second gas jet will stop the motion of satellite in that axis direction. Power systems and rockets are present in this drum. The direction of this motor will be opposite to the rotation of satellite body, so that the antennas point towards earth. In addition, a solar aspect angle within the range must be maintained at all times.

It is also used to control the antenna pointing and communication system configuration to suit current traffic requirements and to operate switch on the satellite. By continuing to use the site you are agreeing to our use of cookies.

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Attitude and orbit control system(AOCS) | Satellite Communication

Most satellite antennas are designed to operate in a single frequency band, for example, C band or Ku band. Astellite drum is covered with solar cells. The communication subsystem is the major part of the satellite. Let X, Y and Z are another set of Cartesian axes. If there is any change in satellite orbit, then it sends a signal regarding the correction to Orbit control subsystem.

Satellite Communication – AOC Subsystem

The pointing accuracy of the 10 m long XMM-Newton is 0. Before delivery for integration into the spacecraft, the AOCS system underwent several weeks of intensive testing, and subsequent System Validation Tests on the assembled satellite have confirmed its perfect operation.

Altitude control subsystem takes care of the orientation of satellite in its respective orbit. This subsystem consists of rocket motors that are used to move the satellite back to the correct orbit when external forces cause it to drift off station and gas jets or inertial devices that control the attitude of the satellite. Given XMM-Newton’s very specific orbit highly elliptical, irregular eclipse seasons, Sun avoidancethis required very complex hardwired coommunication within the unit.

This site was designed with the. Likewise it will never point to within These forces change cyclically over a hour period, since the satellite moves around the earth.