How lasers in space help you find your way

Above our heads, three satellites orbit the Earth. The satellites form the Swarm mission. Onboard the satellites are some complex equipment with the cool name “Absolute Scalar Magnetometers”. Their job is to measure changes in the Earth’s magnetic field. The data is used to create the World Magnetic Model – a map of the Earth’s magnetic field.


Since we started measuring the Earth’s magnetic field, almost 200 years ago, we have watched it shift over time. Revising the World Magnetic Model once every five years was usually enough to keep it accurate.

Reliable navigation in the palm of your hand

Global navigation systems – even your smartphone – rely on the World Magnetic Model to keep us on track, so its accuracy is very important.

Recently, scientists have discovered that the magnetic north is moving faster than usual. To keep our navigation systems reliable, we will need to update the World Magnetic Model with the position of the new magnetic north.

However, you need not worry, this job has been assigned to the Swarm satellites. They will be working hard around the clock – and around the Earth – to make sure that you will still be able to find your way.

What about the lasers?

Right, the lasers actually play an important part. Onboard the satellites, inside the Absolute Scalar Magnetometers, you find our Koheras single frequency lasers. The sensitivity of a magnetometer depends directly on the characteristics of the laser, so we are very proud that our lasers are precise and reliable enough to go into space.

Get more fascinating information about the Earth’s magnetic field at ESA’s web site or read a bit more about our lasers’ role in the Swarm.