Controlling Satellites

Maureen P. / Physics Sec. #337 / 19 May 1997
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In order for satellites to work properly, controlling them is very important and necessary. People on the ground have complete control over their satellite and need to be able to know where the satellite is at all times. They also should be in contact with the satellite at all times. Controlling a satellite can be accomplished by rocket engines, specific types of tracking, guidance systems and Telemetry links.

Rocket Engines:

Rocket engines are one of many ways to control satellites. They help to keep satellites from drifting off course. In order to do this, some systems use small bursts from the rocket engines which are placed around the satellite. One specific rocket engine is the Agena rocket. This rocket is on a satellite called the Seasat. It keeps pointing toward the Earth and gives the satellite an elongated shape which helps provide stabilization.


Satellites are tracked from tracking stations. "Tracking stations are usually ground based but have been placed aboard ships, aircrafts and satellites" (Dooling). There are also specific types of tracking. One type is optical tracking. "Optical tracking is used mainly for orbit determination of inactive spacecraft or of satellites equipped with optical ranging" (Dooling). Another type of tracking is radio tracking. "Radio tracking is used extensively to acquire data from spacecrafts and to transmit commands" (Dooling).

Guidance Systems:

Guidance systems are also a very important part of controlling satellites. They help the satellite to function and to stay on target. There are different types of guidance systems as well. Radio-command is one example. "In the radio-command guidance system, changes in velocity and direction are broadcasted by the spacecraft to a station on the ground. The data is fed into computers that make the calculations required to keep the craft on course. The necessary adjustments are then broadcasted back to the craft and control motors on the craft to carry out the instructions. This procedure may be directed by the ground station or it may be automatic" (Waters 305). One other type of guidance system is the inertial-guidance system. "In an inertial-guidance system, the velocity and direction are measured by an to board sensor system. This information if then fed onboard computers and flight controls" (Waters 305).

Telemetry links:

Telemetry links aid in the way information is transmitted to and from the satellites. "Commands from the ground and details of how the satellite is functioning are transmitted to and from the satellite by Telemetry links. Many scientific satellites collect data continuously but are only in view of the ground stations for a short time. In this case, the data will be recorded on a tape recorder and played back at a higher speed when in contact with the ground station" ("Satellite" 2040).


As you can see, there are many factors involved in controlling a satellite. Some ways that satellites are controlled are by the use of rocket engines, tracking stations, guidance systems and Telemetry links. These are just some examples of how to control a satellite. There are many other ways because the world of satellites is a big field of physics and is being expanded everyday.


Couper, Heather and Nigel Henbest. Space Probes and Satellites. New York: Franklin Watts, 1987.

Dooling, David. "Tracking Station." Grolier Encyclopedia . CD-ROM. Grolier Electronic Publishing, 1993.

"Satellite." How it Works the Illustrated Encyclopedia of Science and Technology. New York: Kingfisher Books, 1991.

Waters, Tom. "Space Satellites." The New Book of Popular Science. Connecticut: Grolier Incorporated, 1996.