Cassini

Spacecraft· NASA / ESA / ASIinactive

Cassini — orbited Saturn 2004–2017, studying its rings and moons; ended with a planned plunge into the planet (the Grand Finale).

Open in 3D viewSee Cassini in the live, interactive 3D map

Key facts

Current speed

6.06 km/s

Distance from Sun

9.45 AU

Status

Completed

Launched

1997

Mission & specifications

Mission

Operator: NASA / ESA / ASI
Launched: October 15, 1997
Status: Completed

Trajectory

Current speed: 6.06 km/s
Distance from the Sun: 9.45 AU
Distance from Earth: 8.73 AU
Distance from Saturn: 4,878,965 km

Cost & funding

Program cost: $3.90 × 10⁹ USD

Mission

Cassini was one of the most ambitious planetary missions ever flown, and it gave us Saturn in extraordinary depth. A joint effort of NASA, ESA and the Italian space agency, it launched on 15 October 1997 and used gravity assists from Venus, Earth and Jupiter to reach the ringed planet. On 1 July 2004 Cassini fired its engine to slip into orbit, becoming the first spacecraft ever to orbit Saturn. Bolted to its side was the European-built Huygens probe, which it released to parachute down to the giant moon Titan; on 14 January 2005 Huygens touched down on a frozen plain, the first landing in the outer Solar System and the most distant landing humans have ever achieved. Cassini went on to spend thirteen years circling Saturn, and its discoveries reshaped the field. It found towering geysers of water ice and vapour erupting from the south pole of tiny Enceladus, betraying a global ocean beneath its shell, laced with organic chemistry. It mapped seas of liquid methane and ethane on Titan — the only other place known to have standing surface liquid — and studied the rings, Saturn's vast hexagonal polar storm, and a flock of moons. As its fuel ran low, the mission ended in spectacular fashion: a 'Grand Finale' of 22 daring dives between the planet and its rings, followed on 15 September 2017 by a deliberate plunge into Saturn's atmosphere, so the spacecraft could never contaminate the ocean worlds it had found.

1997Launch toward SaturnLaunch
Cassini and the Huygens probe depart on a seven-year, gravity-assisted cruise.
2004Saturn orbit insertionArrival
Fires its engine to become the first spacecraft ever to orbit Saturn.
2005Huygens lands on TitanLanding
The probe parachutes to Titan's surface — the most distant landing ever achieved.
2005Geysers on EnceladusMilestone
Finds icy plumes venting from the south pole, revealing a global ocean beneath the crust.
2006Seas on TitanMilestone
Radar maps lakes and seas of liquid methane — the only other world with standing surface liquid.
2017The Grand Finale beginsMilestone
Starts 22 daring dives through the gap between Saturn and its rings.
2017Plunge into SaturnMission end
Ends with a deliberate descent into the atmosphere, protecting the moons it discovered.

Images

The Cassini orbiter at Saturn (artist's concept) — NASA/JPL-Caltech (public domain) · Wikimedia Commons

Saturn imaged by the Cassini orbiter — NASA/JPL/Space Science Institute (public domain) · Wikimedia Commons

Spotlight on Penelope — NASA/JPL/Space Science Institute · NASA Image Library

The Adventure Ahead — NASA/JPL/Space Science Institute · NASA Image Library

Roughed-up Rhea — NASA/JPL/Space Science Institute · NASA Image Library

Saturn Polar Jet — NASA/JPL-Caltech/Space Science Institute · NASA Image Library

Swirling Clouds — NASA/JPL/Space Science Institute · NASA Image Library

Saturn Silhouette — NASA/JPL/Space Science Institute · NASA Image Library

Images from open archives · credit shown per image