The movement of a satellite around the Earth is fixed in either a circular or an elliptical orbit. The satellite can be positioned in a polar orbit, circling the Earth from pole to pole, or placed in an equatorial orbit around the Equator, or in a low Earth orbit, or it may hang in one place, in geostationary orbit. In the first project you can see for yourself how geostationary orbits work.
The type of orbit is chosen according to the job the satellite is there to do. Most communications and weather satellites are placed in geostationary orbit 22,000 miles above the Equator. A satellite in this orbit keeps pace with the turning Earth, and appears to hang motionless over the same spot on the ground. Once a radio dish on the ground is aimed at the satellite, the dish need not be moved again. Other satellites have to be tracked using movable radio dishes that follow the satellite as it crosses the sky. The second project demonstrates the way in which satellites relay signals from one place to another.
About 15 strips of blue card, about 30 strips of red card, rope, a friend.
MAKE A SATELLITE RELAYYOU WILL NEED
Scissors, blue paper, tin can, tape, 1 yardstick, thin card, flat mirror, nonhardening modeling material, flashlight.