solar spacecraft

satellites and rockets

what do satellites do?

GEO satellites

LEO satellites

polar orbits

GPS satellites

polar orbits

Polar orbits are special Low Earth Orbits in which the satellite travels north-south over the Earth's poles, rather than in the more usual east-west direction. The big advantage of this is that in a single day they can observe the entire Earth as it rotates underneath them. This is useful for projects that require the complete Earth to be mapped once a day.

Image of a satellite on a polar orbit, scanning the surface of the Earth

Satellites that study the weather make use of polar orbits. You'll have seen the pictures they produce on the weather reports. They can also give early warnings of severe weather and make measurements of the Earth's atmosphere. Here is an image of a typhoon taken from space.

One such weather satellite is called NOAA-17. This has many scientific instruments for studying the Earth. It also has two instruments which can act as radio relay stations for anyone signalling they are in trouble on land, sea or in the air.

Image of an artists impression of NOAA-17 in polar orbit

Image of one of the first pictures taken by NOAA-17 of the great lakes of the US