The iconic Blue Danube waltz by Johann Strauss II has begun its journey into interstellar space, an act the Vienna Tourist Board and the European Space Agency (ESA) have playfully dubbed the correction of a "cosmic mistake."
On May 31, 2025, a unique live concert in Vienna saw the celebrated waltz transmitted towards NASA's Voyager 1 probe, a piece of music notably absent from the Golden Records sent aboard the Voyager probes in 1977. The initiative, Waltz Into Space, marked a triple anniversary: the 200th birthday of Johann Strauss II, the 50th anniversary of the ESA and 125 years of the Vienna Symphony Orchestra. For decades, Strauss's waltz has served as an unofficial anthem of space, since its evocative use in Stanley Kubrick's film 2001: A Space Odyssey, even being adopted for NASA wake-up calls. Its previous omission from humanity's interstellar musical archive was, for many, an oversight now rectified. Norbert Kettner, Director of the Vienna Tourist Board, articulated the mission's poetic ambition: "Stanley Kubrick’s 2001: A Space Odyssey made the Danube Waltz the anthem of space – its absence from the 1977 Voyager Golden Record was a cosmic mistake that we corrected with Waltz Into Space. At a distance of more than 25 billion kilometres from Earth, Voyager 1 is the most distant man-made object in space. As part of our mission with the European Space Agency, we sent By the Beautiful Blue Danube in the direction of the probe as it travels through interstellar space, making an impact beyond our solar system and inspiring people on Earth to experience culture in Vienna.” The culmination of art and science, the event saw Chief Conductor Petr Popelka lead the Vienna Symphony Orchestra in a performance at the MAK Museum of Applied Arts. The concert's grand finale – Strauss’s waltz – was beamed live to the Deep Space Antenna (DSA) 2 in Cebreros, Spain. From there, the ESA transmitted it as an electromagnetic wave, travelling at the speed of light. The journey to Voyager 1 took just over 23 hours, a symbolic completion of the waltz's cosmic destiny.