A Cassini Spacecraft Image of Saturn
Credit: NASA/JPL/Space Science Institute

On 30 June 2008, NASA’s Saturn-bound Cassini spacecraft completes its four-year prime mission and begins its extended mission, which was approved in April 2008. Cassini’s new two-year mission will address new questions and focus on two of Saturn’s most intriguing moons, Titan and Enceladus.

Cassini’s outstanding achievements include revealing the Earth-like nature of Saturn's largest moon, Titan (5,150 km across), and demonstrating the possible habitability of Enceladus (504 km across), a geologically-active moon.

The new mission is dubbed the Cassini Equinox Mission, as Saturn will pass the equinox in August 2009. It is a unique opportunity for Cassini to study Saturn’s rings when sunlight passes directly through their plane. This event also will allow for monitoring seasonal effects on Saturn and Titan.

"We've had a wonderful mission and a very eventful one in terms of the scientific discoveries we've made, and yet an uneventful one when it comes to the spacecraft behaving so well," said Bob Mitchell, Cassini program manager at NASA's Jet Propulsion Laboratory (JPL). "We are incredibly proud to have completed all of the objectives we set out to accomplish when we launched. We answered old questions and raised quite a few new ones and so our journey continues."

Cassini was launched toward Saturn on 15 October 1997, from Cape Canaveral. The interplanetary cruise to the ringed-giant was 3.5 billion km long, and lasted seven year. Cassini entered orbit around Saturn on 1 July 2004, and almost immediately began sending stunning data of Saturn's rings.

The spacecraft is operating very well. It carries 12 instruments powered by three radioisotope thermoelectric generators. Data from Cassini's nominal and extended missions could lead to possible future missions to Saturn, Titan or Enceladus.

Further Reading

The Cassini-Huygens Mission to Saturn
http://saturn.jpl.nasa.gov/home/index.cfm

Aymen Mohamed Ibrahem
Senior Astronomy Specialist