A satellite is a celestial body that orbits another. An artificial satellite is a man-made object that orbits Earth. Artificial satellites are raised to a desired height above Earth and launched by rockets parallel to Earth's surface. This forward velocity (speed of an object in a specific direction) and the force of gravity keep the satellite in orbit around Earth.
In this project, you will learn about launching speed and its effect on a man-made satellite's orbit. You will discover the best times to see satellites and how to measure their angular velocity. You will also find out why satellites are launched in different directions.
Purpose: To model how an artificial satellite is launched into orbit.
- 2 equal-size books, each about 10 inches (25 cm) long
- index card
- transparent tape
- 3 rulers—2 must be identical and have a groove down the center
- walnut-size piece of modeling clay
- bath towel
- Lay the books end to end on a table.
- Lay the index card on the end of the books farther from the edge of the table.
- Tape the grooved rulers together end to end. Tape only on the ungrooved side. This is your launcher.
- Lay the launcher on the books so that one end is on the index card. Raise that end 2 inches (5 cm) above the book. Put the clay under the end for support. Let the other end of the launcher extend over the end of the books.
- Adjust the books so that the extended end of the launcher is 4 inches (10 cm) from the edge of the table.
- Lay the towel on the floor near the edge of the table. The towel will help stop the marble when it hits the floor.
- Position the marble on the raised end of the launcher, then release it (see Figure 6.1) The marble should land on the towel.
- Observe the path of the marble after it leaves the launcher.
The marble's path curves after it leaves the launcher.
An artificial satellite (man-made satellite) is any object purposely placed into orbit around a celestial body, including Earth. Since the launching of the first artificial satellite in 1957, thousands of artificial satellites have been placed in orbit around Earth. These satellites have many uses for private companies, governments, and educational facilities. This experiment models the launching of an artificial satellite, called the marble satellite.
In this model, the table represents Earth. The top of the books is a position above Earth's surface where the "marble satellite" is launched horizontally, parallel to Earth's surface. After it separates from its launcher, the satellite moves in a curved path. The curve results from the satellite's forward horizontal velocity and the downward pull of gravity. A real satellite would continue revolving around Earth in a curved path called an orbit that would pass through the launching point.
Try New Approaches
If the horizontal velocity of the marble satellite is great enough, gravity pulls it into a curved path past the edge of the table. Demonstrate the effect of different horizontal velocities on the path of the satellite by repeating the experiment, raising the end of the launcher to different heights.