Launching Satellites

Kelly D. / Physics # 337 / 19 May 1997
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[ Where Are They Launched From? ] [ Putting Satellites Into Orbit ] [ Types of Launching Vehicles ]
[ Problems Involved With Launching ] [ Life Span ] [ The Death of a Satellite ]
[ International Killings and Repair Rescues ]
Everyday, satellites are either being launched , repaired, or retrieved in space. Satellites help transmit communications at the speed of light, serve for navigation for the military and help in exploring the universe. They are very important to the world of communication, but it takes a great deal of work to get them in and out of orbit. Launching is essential to satellites , but many problems might be encountered during the launching or retrieving of a satellite, which might cause for repairs to be made in space.

Where Are They Launched From?

The government uses a number of launching areas around the country depending upon the type and orbit of satellite that is to be launched. Most launches occur from Cape Canaveral, Florida for regular satellites. NASA's (National Aeronautics and Space Administration) Wallops Flight Center, located in Virginia is used to launch regular satellites. To launch polar orbits, or satellites which orbit over the North and South Poles, these take place from the Vandenberg Air Force Base in California.

Putting Satellites Into Orbit

Satellites are carried into orbit by shuttles, where they go through a process of being launched. Shuttles flying into an orbit are inclined at 28.5 degrees to the Equator (Broad, A22). Even though a good number of satellites are carried into orbit by space shuttles, most satellites are carried by rockets. The rockets fall back into the ocean after they have launched the satellite and their fuel has run out. Sometimes they are retrieved and are used for other launches. Rockets have the capability to put satellites into orbit which are 120 miles above the Earth. Satellites which need to be put into higher orbits are first put into one orbit around the Earth and then with their motors, are pushed into higher orbits. Once the satellite gets away from the rockets own protective shroud, they are then controlled by signals from ground controllers in the launching center. Space shuttles can carry a maximum of 3 or 4 satellites. These satellites are either pushed into orbit by a space arm or can be gently pushed out into orbit while spinning.

Types of Launching Vehicles

Different types of launching vehicles are used to put satellites into orbit. Two types of launching vehicles used are either solid or liquid fuel propellants, or motors. The solid propellants can be compared to a rocket used in fireworks displays and the liquid propellants, which are forms of kerosene and liquid oxygen are used to provide movement for launching. Another type of launch vehicle includes the use of volatile hydrogen and oxygen combination as fuel. At liftoff, the three large liquid motors are assisted by the solid rocket boosters. The two solid boosters burn out after some time and fall back into the ocean. The other liquid motors are used during the rest of the flight to put the satellite into the proper orbit, to control the satellites orbit and to return the rockets to Earth.

Problems Involved With Launching

Problems such as vibrations and the emission of gasses cause problems during a launch. During launching, vibrations which are transmitted from the launch vehicles and shock loading take over the launching process as they enter the upper stages of launching. To add to the problems, some of the materials, in the launch vehicles, can emit gas or give off particles of their substance such as kerosene or liquid oxygen under a vacuum (How It Works, 2038). This transmission of particles has to be avoided because the particles could be confused as stars or they might contaminate the solar system atmosphere. Satellites which require minor adjustments due to launching difficulties must be adjusted otherwise they will not function. Thrusters or built in rockets have been placed in satellites to assist in making these minor adjustments.

Another problem at launch time is the weather at the launching pad and tracking stations around the world. Unless weather is ideal, where there is very little wind and no rain to affect the rocket, a launch will not take place. Further the tracking stations must be able to follow the rocket into orbit.

During the countdown prior to actual launch, a major problem can occur while the computers are checking all the systems. If the computer encounters an error, the countdown is stopped to fix the problem so the launch can either go on, be scrubbed, or canceled to take place at a later date. To launch with the problem could mean the loss of a satellite and millions of dollars invested in the launch, and the lives of the astronauts who are flying the mission.

Life Span

Once in orbit, satellites may last for a few years to a few hundred years depending on its' size and its' orbital distance from Earth. Since outer space has become crowded with satellites, meteors, and space junk from failed launches and non-working satellites, many of the working satellites might have to be raised to higher orbits by the ground controllers with the use of the thrusters to escape the crowding in various orbits to extend their lives.

The Death of a Satellite

Many factors can contribute to the slowing down or even the death of a satellite. Even before some satellites reach space, 1 in 20 are rendered useless by either being jolted on lift-off, perish in fires of defective rocket blasts or are put into improper orbits (Canby, 282). The atmosphere in space is less dense than on Earth and approximately 124 miles above the Earth. There is no part of the space's atmosphere which is an absolute vacuum. In time, a satellite will lose velocity or speed and won't be able to go high enough and will eventually fall out of orbit and disintegrate falling towards Earth because of the tremendous speed and friction. Some satellites will begin to lose the balance in the pull of the Earth's gravity and will fall toward the Earth. Friction will be a major cause for the death of most satellites. The friction of air particles in the high atmosphere and the gentle pressure of the sun's energy will cause a satellite to fall back in the Earth's atmosphere. Falling into the atmosphere means that the satellite will be exposed to intense heat as it collides with large numbers of molecules and ions and this causing the satellite to burn up in flames even before it reaches Earth. Satellites that escape the Earth's gravitational field have a good chance to crash with the moon or planets and they might even begin to orbit the sun.

International Killings and Repair Rescues

Satellites in orbit might be killed on purpose while others need to be rescued to get repaired. Since satellites can cause interference with other orbits or are just not needed anymore, countries such as the United States and the Soviet Union have taken actions to kill these satellites. The United States uses a F-15 fighter which fires a two stage missile at it's target, the satellite. Using telescopes as it's eyes, the 50 pound warhead adjusts it's flight path so that it might intercept the path of the satellite. The Soviet Union uses a heavy satellite, the hunter-killer, which is boosted to the same orbital path as the target satellite. The hunter-killer, when in the same orbit as the target satellite , closes in and explodes destroying the target satellite (Canby, 333). Satellites in need of repair and rescue are assisted by shuttles while the satellites are in low orbits. Many satellites get repaired while other satellites in the wrong orbit get returned to Earth to be launched into the correct orbit or to be repaired.


Satellites are a very important part of our communication system and without them, the lives of many people would be totally different. The life and death of satellites are a very crucial factor to the world today. Everyday, new discoveries are being made on how to make the launching and retrieving process a little more easier, while at the same time, technicians are learning new ways on how to extend the life span of a satellite.


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