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Why Cassini? A Closer Look
Saturn system Image left: A montage of images from Voyager 1 shows some of the 31 moons of the Saturn system
Image credit: NASA/JPL

When considering such a complex, collaborative effort as the Cassini-Huygens mission, one might ask the question, "Why build it in the first place?"

The answer comes even before the mission's conception. At the beginning, a basic set of science goals are illustrated in a detailed, comprehensive mission plan that scientists hope to achieve and bring to the public at large.

In this case, through Cassini we hope to gain a better understanding of the planet Saturn, its famous rings, its magnetosphere, its principal moon Titan and its other moons or "icy satellites."

Along with extensive preparation, planning and tracking throughout the mission, science objectives are divided into two parts: The goals that occur on the way to the ringed planet, and then those that will occur after the mission's arrival at the Saturnian system.

Watch the Science Objectives Movie:
1.7 Mb QuickTime | 5.3 Mb QuickTime

En Route to Saturn:

To ensure all instruments onboard the spacecraft are working properly, checks were performed via remote control at launch time as well as after 14 months in space. This includes routine instrument maintenance, Gravitational Wave Experiments, instrument calibrations, and conjunction experiments for a time period of at least 30 days. These objectives are to prepare Cassini for its upcoming tour of Saturn.

There are 12 instruments onboard the Cassini orbiter, and 6 instruments onboard the Huygens Probe. These instruments are all designed to perform in-situ (on-site) studies of elements of Saturn, its atmosphere, moons, rings and magnetosphere. The instruments will study temperatures, plasma levels, neutral and charged particles, compositions of surfaces, atmospheres and rings, solar wind, and even dust grains in the Saturn system. Other instruments will also perform spectral mapping for high-quality images of the ringed planet, its moons, and rings.

The sophistication of the design and implementation of the instruments onboard the spacecraft create many other benefits, including the potential for technology spin-offs into the commercial world, international cooperation and education and discovery for people of all ages.

After Arrival at Saturn:

Cassini-Huygens Image right: Spacecraft on the launch pad.
Image credit: NASA/JPL

The spacecraft has a series of science objectives in five areas: Saturn, the rings, Titan, other icy satellites and the planet's magnetosphere.

For the planet itself, Cassini will examine the atmosphere and cloud features and try to learn what Saturn was like during its formation and evolution. The spacecraft will also look at the composition and structure of the planet's famous rings, and investigate their interaction with moons. (+ View All Saturn Objectives, + View All Rings Objectives)

The largest moon, Titan, will get much attention, with a visit from the Huygens probe in January 2005. Science objectives include determining the components of its atmosphere, and figuring out how the moon and its atmosphere may have formed. The mission also aims to solve the mystery of Titan's surface, determining if it's liquid or solid, and if there is a bright continent, as indicated in Hubble Space Telescope images taken in 1994. (+ View All Titan Objectives)

The spacecraft will also investigate several of the system's icy moons, determining how they were formed, what they're made of and how they interact with the rest of the system. Finally, Cassini will determine the configuration of Saturn's magnetic field and its interactions with the solar wind, Saturn's moons and rings.(+ View All Icy Satellites Objectives, + View All Magnetosphere Objectives)

Cassini Mission
NASA's Jet Propulsion Laboratory