Ariane 5 ES Galileo

On 17 November 2016, the Ariane 5 ES Galileo was used to accelerate the deployment of Europe’s new satellite navigation system, Galileo. 

In development since 2012, this new Ariane variant has evolved from the version used to place ESA’s 20 t ATV supply vehicle into low orbit. 

The new launcher has to carry a lighter payload (about three tonnes) but needs to take it up to the much higher altitude of 23 522 km.

The dispenser built for Galileo missions has a double role. Firstly it must hold the quartet of satellites securely in place during the loads induced by the liftoff, and then the nearly four-hour long flight to medium-Earth orbit.

Then, once the Ariane 5 EPS upper stage reaches its target altitude, the dispenser has to release the four Galileo satellites smoothly in pairs with a 20-minutes interval using a pyrotechnic release system triggered by separate igniters, each one firing half a second after the other.

While the four Galileos manoeuvre themselves down to their final set height, Ariane’s upper stage is left in a stable ‘graveyard orbit’ which is not interfering with the Galileo operational orbit.