Strauss’ “Blue Danube” waltz has finally made it into space, nearly a half-century after missing a ride on NASA’s Voyagers. The European Space Agency’s big radio antenna in Spain beamed the waltz into the cosmos Saturday. Operators aimed the antenna at Voyager 1, the world’s most distant spacecraft more than 15 billion miles away. The Vienna Symphony Orchestra performed the “Blue Danube” during the transmission. Launched in 1977 and now in interstellar space, each of the twin Voyager spacecraft holds a Golden Record full of music but nothing from the waltz king.