Space debris in numbers

About 130 million of fragments of space debris floating in low Earth orbit (LEO) and the total mass of all this space debris is more than 9500 tonnes according to data from the ESA. This space debris are moving at speeds of up to 27,000 kilometres per hour, which is fast enough to ensure that even a small fragment can damage seriously a satellite or spacecraft.

These figures are extremely worrying and this situation is considered as a problem because of the danger they pose to spacecraft and satellites, but also because of  the way they contradict the idea of sustainability in space.

What is space debris?

Space debris refers to man-made objects that are floating in space, mostly in the Earth’s orbit, and which serve no useful purpose. It includes such large pieces of debris as whole spacecraft that are no longer in use, or the discarded stages of launch vehicles or depleted rockets, but also smaller pieces like the fragments of broken equipment, solidified liquids leaked from derelict spacecraft and even splashes of paint, etc.

Space debris in figures

According to NASA, there are around 23,000 pieces of debris larger than a baseball orbiting the Earth, half a million scraps of material about the size of a marble or slightly larger (up to 1 centimetre or more), and approximately 100 million fragments measuring around one millimetre or more.

For its part, the European Space Agency (ESA) has also estimated the size of this problem that worries all agencies in this sector across the world. There have been 6,100 successful rocket launches since the start of the space age in 1957, and they have put some 12,020 satellites in orbit.

This enormous amount of activity in space means that the amount of debris that the space surveillance networks regularly tracks and lists in its logs is close to 29,110, and the total mass of all this space debris in the Earth’s orbit is more than 9500 tonnes, according to ESA figures.

There are also estimates of the number and size of objects orbiting the planet which can cause damage to satellites and space missions. The largest of these, measuring more than 10 centimetres, number around 34,000, while the next group, between 1 and 10 centimetres, are estimated at 900,000. Finally, there are around 128 million objects measuring between a millimetre and a centimetre.


The problem of space debris

This enormous amount of space debris that we are talking about is moving at speeds of up to 27,000 kilometres per hour, which is fast enough to ensure that even a relatively small fragment of debris can damage a satellite or spacecraft. Even a splash of paint travelling at this speed can cause problems and affect the structure of a spacecraft.

In fact, this has happened on several occasions. For example, several of the windows of the space shuttle had to be replaced because of damage caused by the impact of material which turned out under analysis to be paint.

At Solar MEMS we have talked about responsible satellite missions as a way of helping to reduce this problem, a challenge that faces all of us who work in the aerospace industry. In this article you will find some of the most important measures that are being taken to counter the effects of space debris in low Earth orbit (LEO). Most of them are linked to the idea of manufacturing responsible components, the fast and safe removal of spacecraft once they have outlived their purpose, and ensuring that resources like batteries and fuel are fully used up to prevent explosions, and so on.

(Image used under creative commons license from the European Space Agency, an artists illustration of the huge numbers of satellites and space debris in orbit today).