Graphic courtesy of NASAexplores.com.
Graphic courtesy of HowStuffWorks.com.
Getting the satellite in the right orbit is tricky.
Graphic courtesy of the Gulf of Maine Aquarium Research Institute, octopus.gma.org.
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How Satellites Work
| Sound travels in
radio waves, the longest waves in the electromagnetic spectrum. Radio
waves can travel great distances, but only in straight lines, so on a
curved Earth, that's a problem.
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Graphic courtesy of NASAexplores.com. |
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Graphic courtesy of HowStuffWorks.com.
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Satellites act like ping-pong paddles to bounce radio waves back to Earth. Signals from ground stations (green building seen at left) are captured, amplified and sent back down to a dish receiver on Earth. | |
| A satellite's life
expectancy is about 10 years when its fuel thrusters (which keep
it aligned in the proper orbit) run out of gas.
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Getting the satellite in the right orbit is tricky. Graphic courtesy of the Gulf of Maine Aquarium Research Institute, octopus.gma.org.
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| Satellites travel in various
orbits depending on what they're built for. In the animation at
right, the satellite closest to the planet is a low-Earth
satellite (best for mapping weather). The red satellite
is in geosynchronous orbit (meaning it orbits at the same speed as
Earth) and is used for
communication (TV, television, navigation). The outermost satellite is
for deep space study.
Graphic above courtesy of the Gulf of Maine Aquarium Research Institute, octopus.gma.org. |
 Animation courtesy of met.tamu.edu/class/ ATMO151 |
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Satellites don't bump into each other because each one has been assigned its own 2-degree arc in the orbital plane.
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Graphic designed by the Gulf of Maine Aquarium Research Institute, courtesy of octopus.gma.org. |
Image courtesy of the Gulf of Maine Aquarium Research Institute, octopus.gma.org. |
What's Inside a satellite: Satellites are made of a lightweight but solid metal or composite that's lined with a thermal blanket. They are equipped with a power source (solar cells or batteries). They all have an onboard computer to control their systems. A radio and antenna are onboard to receive signals and a repeater amplifies the signal before returning it to Earth. An attitude control system (gas-fueled jets) keep the satellite pointed in the right direction. Some satellites also have cameras or mirrors for taking photographs.
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A satellite in a Space Shuttle cargo bay prepared for launch. Photo courtesy of NASA Glenn Research Center. |
Launching a Satellite Shuttles are launched into orbit by rockets or, until 2002, by the U.S. Space Shuttles, which carried the satellites in their cargo bay. (The Shuttle program is temporarily grounded while the heat shields are being redesigned.)
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