January 10, 2021

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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This set of communicatjon axis provides the information about orientation of the satellite with respect to reference axes. 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.

However, should any serious anomaly occur, such as a prolonged loss of contact, XMM-Newton will automatically enter a survival mode and wait for direct control to be re-established from Earth. This method is called as three-axis method.

Attitude and orbit control system(AOCS) | Satellite Communication

An electric motor drives this communication system. Altitude and Orbit Control AOC subsystem consists of rocket motors, which are capable of placing the satellite into the right orbit, whenever it is deviated from the respective orbit. In this method, each axis contains two gas jets.

These systems are partly on the satellite and partly at the controlling earth station. The second gas jet will be operated for same period of time, when the satellite reaches to the desired position. Reaction wheel courtesy of MMS. ESA’s X-ray space on targets distant X-ray sources for long periods often exceeding ten hours and one of the key requirements of the satellite is its very high pointing accuracy and stability.

Then, it will resolve that issue by bringing the satellite into the correct orbit. The pointing accuracy of the 10 m long XMM-Newton is 0. By continuing to use the site you are agreeing to our use of cookies. Likewise it will never point to within The orientation of a sxtellite in space is crucial, whether it be for telecommunications or Earth observation craft, or for astronomy missions like XMM-Newton. In this method, the body of the satellite rotates around its spin axis.



Satellite Communication – AOC Subsystem

The receiver-transmitter units are known as transponders. A satellite which uses multiple frequency bands usually has four or more antennas.

If there is a change in altitude of the satellite, then the angles between the respective axes will be changed. All communications satellite derive their electrical power from solar cells. Satellites are of this type are called as spinners. The fully redundant AOCS represents some kg communicatoin electronics: Let X, Y and Z are another set of Cartesian axes. The power is used by the communications system, mainly in its transmitters, and also by all other communiction systems on the satellite.

Given XMM-Newton’s very specific orbit highly elliptical, irregular eclipse seasons, Sun avoidancethis required very complex hardwired logic within the unit.

The telemetry system sends data derived from many sensors on the satellite, which monitor the satellites health, via telemetry link to the controlling earth station. These three axes define the altitude of satellite. ESA uses cookies to track xommunication to our website only, no personal information is collected.

Orbit control subsystem is useful in order to bring the satellite into its correct orbit, whenever the satellite gets deviated from its orbit. 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

Altitude control subsystem takes care of the orientation of satellite in its respective orbit. If there is any change in satellite orbit, then it sends a signal regarding the correction to Orbit control subsystem. We know that satellite may deviates from its orbit due to the gravitational forces from sun, moon and other satellife. They will provide the rotation in both directions of the three axes.


The tracking system is located at this earth station and provides information on the range and the elevation and azimuth angles of the satellite. For redundancy XMM-Newton carries a second star-tracker telescope.

Note that this is not a bright source avoidance cone, but driven by requirements on the spacecraft’s alignment with respect to the Sun satelliite ensure sufficient energy supply and thermal stability. It is responsible for the detection of anomalies of whatever origin and their correction. In this way, the AOC subsystem takes care of the satellite position in the right sateplite and at right altitude during entire life span of the satellite in space.

The letter use is housekeeping, since these subsystems serve to support the communications system.

So, the second gas jet will stop the motion of satellite in that axis direction. During launching phase, the satellite spins when the small radial gas jets are operated.

Two types of transponder in use: Im subsystem consists of rocket motors sateolite 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. In addition, a solar aspect angle within the range must be maintained at all times. The communication subsystem is the major part of the satellite. Following are the two methods to make the satellite that is present in an orbit as stable.

Most satellite antennas are designed to operate in a single frequency satlelite, for example, C band or Ku band.

Due to this, the spin axis gets stabilized and the satellite will point in the same direction. Attitude and orbit control system AOCS.