The Heidelberg Laureate Forum Foundation invites you to visit the exhibition “Mathematics of Planet Earth” at Karlstorbahnhof in Heidelberg, Germany! It runs from July 5 to Aug 2, 2015, for the first time in Heidelberg. It offers a big variety of exciting adventures for children and adults alike.

# Satellites under control

hands-on

## Licence

## Credits

- Design and Implementation

## Website

Telecommunications, navigation, meterorology, etc., but also cell phones, GPS, Internet, provide numerous reasons to install satellites orbiting around the Earth. For this purpose, mathematicians select and optimise trajectories and orbits of spacecrafts with more and sophisticated techniques.

Controlling the trajectory at each instant!

A satellite will remain on its orbit without energy if is is given the right speed: this speed depends on the altitude of the orbit. There is only one possible altitude for a geostationary satellite: the one for which the centrifugal force exerted on the satellite is exactly equal to the gravitational attraction of the Earth.

The same type of techniques can be used when designing interplanetary missions. In that case, the spacecraft is accelerated by passing close to celestial bodies. Moreover, to minimize energy spent in deceleration, its speed of approach should be small close to the celestial bodies it is visiting.

This module is part of the MPE exhibition. You can rent this module for a lumpsum fee. A detailed manual how to rebuild this module will be shared.