The Cassini spacecraft that has orbited Saturn for the last 13 years would weigh 4,685 pounds on Earth and, at 22 feet high, is somewhat longer and wider than a small moving van tipped on its rear. Bristling with cameras, antennas and other sensors, it is one of the most complex and sophisticated spy robots ever set loose in interplanetary space.

On Friday morning, the whole world will hear it die.

At the Jet Propulsion Laboratory in California, the scientists of the Cassini mission will figuratively ride their creation down into oblivion in the clouds of Saturn. They will be collecting data on the makeup of the planet’s butterscotch clouds until the last bitter moment, when the spacecraft succumbs to the heat and pressure of atmospheric entry and becomes a meteor.

So will end a decades-long journey of discovery and wonder.

The Cassini-Huygens mission, as it is officially known, was hatched in the 1980s partly to strengthen ties between NASA and the European Space Agency and partly because, well, where else in the solar system would you want to go? With mysterious, mesmerizing rings and a panoply of strange moons (62 and counting), Saturn was the last outpost of the known planets before the discoveries of Uranus, Neptune and Pluto.