Six super satellite facts! What do they actually do?

Video caption, Record-breaking rocket launch

India has created history by launching a record 104 satellites on a single mission.

Check out this video of the record-breaking rocket taking off.

All but three of the satellites are from foreign countries, most of them from the United States.

The launch took place from Sriharikota space centre in south India and overtook the previous record of 37 satellites launched by Russia in 2014.

The Indian government is spending more and more on its space programmes and it also announced plans to send a mission to Venus.

But what are satellites and what are they for?

What is a satellite?

Image source, NASA

Image caption, Nasa's Aqua Satellite looks at Earth's water cycle

A satellite is a moon, planet or machine that orbits a planet or star. For example, Earth is a satellite because it orbits the sun.

But usually, the word "satellite" refers to a machine that is launched into space and moves around Earth.

What are they used for ?

Thousands of artificial, or man-made, satellites orbit Earth - some are used to track weather, some are used to take pictures of space, other planets and galaxies. These pictures help scientists better understand the solar system and universe.

Image source, Getty Images

Image caption, The Sat Nav in your smartphone or family car uses satellites to work out where you are on the road and make sure you're headed in the right direction!

Some satellites are used for communications: beaming TV signals and phone calls around the world.

A group of more than 20 satellites make up the Global Positioning System, or GPS. If you have a GPS receiver, these satellites can help figure out your exact location like on your phone or your satnav.

Which was the first satellite in Space?

Image caption, This is Sputnik 1 the first sateliite in space

Sputnik 1 was the first satellite in space. The Soviet Union launched it in 1957.

How many satellites are up there?

NASA says there are about 1,100 active satellites, both government and private. Plus there are about 2,600 ones that no longer work. The oldest one still in orbit, which is no longer functioning, was launched in 1958.

Image caption, The Funcube satellite sends and receives messages as it orbits the earth. It weighs less than 1kg.

How big are they?

Satellites come in all different sizes. Some communication satellites can be as big as a minibus and weigh up to 6 tons. But others that are used briefly are 4 inch cubes and weigh about one kilogramme.

Image source, ESA

Image caption, Many satellites sit around the earth looking down sending and receiveing messages from below!

Why don't satellites crash into each other?

Actually sometimes they do. Crashes are rare because when a satellite is launched, it is placed into an orbit designed to avoid other satellites but the chances of a crash increase as more and more satellites are launched into space.

Two communications satellites - one American and one Russian - collided in space in February 2009. This, however, is believed to be the first time two man-made satellites have collided accidentally.