ESA Swarm constellation heads north

The Swarm mission will study the complexities of Earth's protective magnetic field. The magnetic field acts as a shield, protecting the planet from charged particles that stream towards Earth in solar winds. Without this shield, life on Earth would be impossible. 

The field is mainly generated deep inside Earth by an ocean of swirling iron that makes up the liquid outer core. How the magnetic field is generated and how it changes over time is complex and not fully understood. But with a new generation of magnetometers, Swarm will provide greater insight into these natural processes and the 'weather' in space. Credits: ESA/AOES Medialab.

The three satellites that make up ESA's Swarm magnetic field mission were unvieled last week to the media. Following a demanding testing programme, the satellites were displayed in the cleanroom before they are shipped to Russia for their July launch.

Swarm is ESA's first constellation of Earth observation satellites designed to measure the magnetic signals from Earth's core, mantle, crust, oceans, ionosphere and magnetosphere, providing data that will allow scientists to study the complexities of our protective magnetic field.

The magnetic shield protects the planet from charged particles that stream in as the solar wind. Without this shield, life on Earth would be impossible.

This shield is generated mainly deep inside Earth by an ocean of swirling iron in the liquid outer core. How the magnetic field is created and how it changes over time is complex and not fully understood.

This force is constantly changing - at the moment, it shows signs of significant weakening.

But with a new generation of sensors, the Swarm constellation will provide greater insight into these natural processes and the 'weather' in space.

Swarm will be ESA's fourth Earth Explorer mission in orbit, following GOCE, SMOS and CryoSat.

In five months, the trio of satellites will be launched together on a Rockot launcher from the Plesetsk Cosmodrome in northern Russia.

Two will orbit very close together at the same altitude - initially at about 460 km - while the third satellite will be in a higher orbit of 530 km.

The different near-polar orbits, along with the various Swarm instruments, improve the sampling in space and time. This helps to distinguish between the effects of different sources of magnetism.