Cassini to Saturn

Explore Cassini's Interplanetary Bus Trip through our solar system!

Launched in 1997, the Cassini mission is taking the long road to its goal: the planet Saturn. Like a bus trip across the country, Cassini isn't taking the fastest route to Saturn, its taking the least expensive. By cruising the inner solar system, making two flyby's of Venus (4/21/98 and 6/20/99) and one of Earth (8/17/99), Cassini gets the equivalent boost of 68,040 kilograms (75 tons) of rocket fuel!

As mentioned above Cassini passed near Earth on August 17^th. Because Cassini uses atomic power some people have reacted in a negative way to the mission and the Earth flyby.

First off, atomic power is necessary for any spacecraft that will explore the distant solar system. Saturn is 10 times farther from the Sun than Earth. This means that sunlight is 100 times fainter at Saturn than it is at Earth! Therefore using solar cells is impossible because the sunlight is just too weak at Saturn.

Atomic power really is the only option for a spacecraft that will operate this far from our Sun. With that in mind, the designers of the power system, spacecraft and launch vehicle have worked to prevent any public danger at critical times like Cassini's launch and the upcoming Earth gravity assist.

Cassini made its closest approach to Earth on Tuesday, August 17 at 6:28 p.m. Central Daylight Time (August 18 at 03:28 Universal Time). The spacecraft passed Earth at an altitude of about 1,171 kilometers (727 miles) over the eastern South Pacific. The flyby gave Cassini a 5.5-kilometer-per-second (about 12,000-mile-per-hour) boost in speed.

Cassini's next gravity assist comes as it makes a distant pass of Jupiter on December 30^th of the year 2000 giving it the additional speed it needs to reach the ringed planet on July 1^st, 2004. As it passes Jupiter, it will study it along with the Galileo probe that currently is in Jupiter orbit.

Cassini's first image of Jupiter - taken October 1, 2000 from a distance of 84.1 million km from Jupiter!

Why Explore Saturn?

Mission Objectives:

• Study its atmospheric properties including its composition, winds, temperature, internal structure and ultimately the origin and evolution of Saturn itself.

• Determine their structure, composition and the interrelations between the rings and satellites of Saturn

• Deploy the Huygens lander to Saturn's moon Titan to study its atmosphere including its winds, temperature, compostion.
• Use Huygens, along with Cassini's radar, map Titan's surface and to determine its composition.

• Map the worlds with the goal of determining their characteristics, geological histories and internal structure

• Understand the composition of the magnetosphere and its interactions with the solar wind, satellites and rings.

Images of Cassini's Path: