So Long, Saturn

Cassini’s Marvelous Mission Is Coming to an End.

- Rachel Zimmerman Brachman

If you’re under 20, NASA’s Cassini spacecraft has been in space your whole life. If you’re under 13, Cassini has been orbiting Saturn your whole life. Thi robotic spacecraft is about a billion miles (1.6 billion km) from Earth, learning about Saturn’s rings and moons, watching its storms, and measuring its moons.

Scientists have lots of questions about Saturn. Why does Saturn have massive storms that last for months or years? How old are its rings, and how were they formed? Could any of its moons support life? NASA’s Cassini spacecraft is helping scientists answer these questions, and many more.

A SPACECRAFT WITH A SPECIAL BLANKET

As big as a school bus, Cassini is the largest interplanetary spacecraft that NASA has ever built.

Cassini ’s shiny gold-colored foil blanket protects the spacecraft from tiny bits of rock that could damage its sensitive scientific instruments. The blanket also keep the spacecraft warm in the cold vacuum of space. Some of the layers of insulation are made from materials similar to those in bulletproof vests.

The large, white, dish-shaped communications antenna at the top of the spacecraft points toward Earth. Cassini uses the antenna to transmit its pictures and data as radio signals. The signals travel all the way to the Earth-based Deep Space Network—a group of enormous radio antennas located in Spain, Australia, and California. This network also sends commands to Cassini. Traveling at the speed of light, the signals sent to and from Cassini can take an hour and a half to traverse the vast distance between the planets.

Cassini has 12 different science instruments on board, including cameras, radar, a magnetic field detector, and instruments to figure out which chemical elements are present in Saturn and its moons.