THE VOYAGER PROGRAM
The Voyager program is an ongoing American scientific program that employs two robotic Interstellar probes, Voyager 1 and Voyager 2. They were launched in 1977 to take advantage of a favorable alignment of Jupiter, Saturn, to fly near them while collecting data for transmission back to Earth. After launch the decision was taken to additionally send Voyager 2 near Uranus and Neptune to collect data for transmission back to Earth.
As of 2021, the two Voyagers are still in operation past the outer boundary of the heliosphere in interstellar space. They both continue to collect and transmit to Earth useful data.
"Voyager did things no one predicted, found scenes no one expected, and promises to outlive its inventors. Like a great painting or an abiding institution, it has acquired an existence of its own, a destiny beyond the grasp of its handlers." — Stephen J. Pyne