NASA Observatorium Education-Reference Module

Orbit Simulators

Kepler's third law is illustrated for circular orbits, although the law also applies to elliptical orbits. Click on either of the buttons on the right. The satellite's motion will simulate either the orbit of NASA's space shuttle or that of a satellite in a geosynchronous orbit. A geosynchronous orbit is one with an orbital period equal to the period of the rotation of the Earth. This means that for circular orbits above the Earth's equator, the satellite will always remain above the same point on the Earth.

You can also click on the satellite and drag it to other orbits. The satellite's altitude above the Earth's surface and orbital period are given on the right.

Notice how much slower the satellite moves in a large orbit, and how much longer it takes to complete an orbit than when it is closer to the Earth. A mathematical relationship exists between the orbital period and the size of the orbit, i.e., the distance between the center of the Earth and the satellite. The relationship states that the square of the orbital period is proportional to the cube of the size of the orbit.

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Comments to: Observatorium Curator mailto:curator@rspac.ivv.nasa.gov