2025 marks a landmark year for Europe’s ‘bridge between Earth and space’. The European Space Agency’s Estrack satellite tracking network turns 50.

Since its inception in 1975, Estrack – ESA’s global network of ground stations – has formed the vital communication bridge between satellites in orbit and mission control at the European Space Operations Centre (ESOC) in Darmstadt, Germany.

Now comprising six stations spanning six countries, Estrack has grown into a strategic asset for Europe, enabling communication with spacecraft, transmitting commands and receiving scientific data.

The network keeps an eye on satellites no matter their location: tracking them across Earth orbit, voyaging to comets or asteroids, keeping station at the scientifically important Sun-Earth Lagrange points, and deep into our Solar System. It even keeps tabs on European launchers as they soar into orbit, ensuring no rocket is ever out of reach.

Fittingly, this celebration of technological excellence coincides with the 200th birthday of Johann Strauss II and the 50th anniversary of ESA. To honour this convergence of milestones, ESA and the Vienna Tourist Board are orchestrating a unique mission: broadcasting The Blue Danube Waltz to its destined home among the stars.

Don’t miss the live concert of the Wiener Symphoniker (Vienna Symphony Orchestra) on Saturday, 31 May. The event will start at 20:30 CEST and the transmission from ESA’s Cebreros antenna will occur at 21:30 CEST.

The live stream can be followed via space.wien.info and the Vienna Instagram channel.

Waltzing celebration for half a century of European satellite tracking