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.

Author: Kagal Mami
Country: Myanmar
Language: English (Spanish)
Genre: Photos
Published (Last): 6 July 2013
Pages: 415
PDF File Size: 3.13 Mb
ePub File Size: 16.6 Mb
ISBN: 462-2-19739-350-1
Downloads: 60726
Price: Free* [*Free Regsitration Required]
Uploader: Mauzahn

In this method, the body of the satellite rotates around its spin axis. The orientation of a satellite in space is crucial, whether it be for telecommunications or Earth observation craft, or for astronomy missions like XMM-Newton. A vital requirement of the XMM-Newton mission is that its delicate science detectors must not be damaged by luminous sources in the sky.

The second gas jet will be operated for same period of time, when the satellite reaches to the desired position. All eventual failures must be detected. ESA’s X-ray space observatory 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.

Due to this, the spin axis gets stabilized and the satellite will point in the same direction. Note that this is not a bright source avoidance cone, but driven by requirements on the spacecraft’s alignment with respect to the Sun to ensure sufficient energy supply and thermal stability.

They will provide the rotation in both directions of the three axes. If there is any change in satellite orbit, then it sends a signal regarding the correction to Orbit control subsystem.

  JAZZY 1143 PDF

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. The fully redundant AOCS represents some kg of electronics: 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.

Let X, Y and Z are another set of Cartesian axes. So, the second gas jet will stop the motion of satellite in that axis direction. Reaction wheel courtesy of MMS. Communicwtion three axes define the altitude of satellite.

ESA Science & Technology: Engineering

In satelltie, it can be rotated at 30 to rpm in order to produce a force, which is of gyroscopic type. This method is called as three-axis method. These systems are partly on the satellite and partly at the controlling earth station. The pointing accuracy of the 10 m long XMM-Newton is 0.

Satellite Communication – AOC Subsystem

This set of three axis provides the information about orientation of the satellite with respect to reference axes. Power systems and rockets are present in this drum.

This drum is covered with solar cells. You can also try this books 1. 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.

Aocw maximum satfllite speed of the reaction wheels is rpm. Orbit control subsystem is useful in order to bring the satellite into its correct orbit, whenever the satellite gets deviated from its orbit. If there is a change in altitude of the satellite, then the angles between the respective axes will be changed.


This site was designed with the. It is responsible for the detection of anomalies of whatever origin and their correction. After this, the de-spin system operates in order to make the TTCM subsystem antennas point towards earth station.

These forces change cyclically over a hour period, since the satellite moves around the earth. 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.

Spinner contains a drum, which is of cylindrical shape. Two types of transponder in use: Most satellite antennas are designed to operate in a single frequency band, for example, C band or Ku band.

Satellite Communication AOC Subsystem

AOC subsystem is helpful in order to make the antennas, which are of narrow beam type points towards earth. The power is used by the satellitf system, mainly in its transmitters, and also by all other electrical systems on the satellite. We know that satellite may communicarion from its orbit due to the gravitational forces from sun, moon and other planets.

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

In this method, communicatiom axis contains two gas jets. In addition, a solar aspect angle within the range must be maintained at all times.

Likewise it will never point to within