After 27 years of exploits and 111 successful launches, Ariane 5 lifted off for the final time on July 4 last. Let’s take another look its some of its most significant missions. The series continues here with Galileo.

Galileo, an ultra-high performance satellite-based global positioning system, is one of Europe’s flagship programs. It is based on a constellation of satellites, a worldwide network of 16 stations, two control centers in Italy and Germany, and two security monitoring centers in France and Spain.

Taking over from the Soyuz launcher, which had already launched 14 Galileo satellites from the European spaceport in Kourou, French Guiana, between October 2011 and May 2016, Ariane 5 gave the program a boost by launching four satellites in one go on November 17 of the same year.

Ariane 5 was specifically adapted for this launch, because the mission was a special one. Unlike telecommunications satellites, which are equipped with propulsion systems providing some of the energy they need to reach orbit, the Galileo global positioning satellites had to be carried virtually up to their final orbit, at an altitude of 22,922 km.

The Ariane 5 ES version was therefore chosen, as it had already been used to send five European ATV freighters to the International Space Station between March 2008 and July 2014. It was equipped with the Aestus reignitable engine and a specially developed dispenser, and placed the four satellites in the planned medium Earth orbit (MEO) during a marathon flight lasting almost four hours!

After several weeks of planned drift, followed by carefully executed maneuvers, the four satellites launched by Ariane 5 reached their operational positions in January and February 2017. In December 2017 and July 2018, an Ariane 5 ES was to repeat the same mission.

The Galileo fleet today comprises 28 satellites, 12 of which were launched by Ariane 5. The constellation is under the control of civilian authorities (unlike the American GPS) and is fully operational, already offering ultra-precise positioning, navigation and synchronization services to more than 2 billion users worldwide.