Cassini-Huygens timeline

Cassini image of Saturn, February 2004

This page is a chronology of events which have occurred or are expected to occur during the Cassini-Huygens Mission to Saturn and Titan.

1997

October 15 - Cassini launched at 08:43 UTC.

1998

April 27 - Gravity-assisted flyby of Venus

1999

June 24 - Gravity-assisted flyby of Venus.

Picture of Moon during flyby

August 18 03:28 UTC - Gravity-assisted flyby of Earth. An hour 20 minutes before closest approach, Cassini made the closest approach to the Moon at 377,000 km, and took a series of calibration images.

2000

January 23 - flyby of Asteroid 2685 Masursky around 10:00 UTC. Cassini took images (See Press Release) 5 to 7 hours before at 1.6 million km distance and estimated a diameter of 15-20 km.

Jupiter flyby picture

December 30 - Gravity-assisted flyby of Jupiter. Cassini was at its closest point to Jupiter at this date, and performed many scientific measurements. It also produced the most detailed global color portrait of Jupiter ever produced (seen on the right); the smallest visible features are approximately 60 km (37 miles) across.

2001

May 30 - During the coast phase between Jupiter and Saturn, it was noticed that "haze" became visible in the pictures taken by the narrow-angle camera of Cassini. This was first seen when a picture of the star Maia in the Pleiades was taken after a routine heating period.

2002

July 23 - In late January, a test was performed to remove the "haze" from the narrow-angle camera lens by heating it. Warming the camera to 4 degrees Celsius (39 degrees Fahrenheit) for eight days produced the hoped results. Later, the heating was extended to 60 days, and a picture of the star Spica showed an improvement of more than 90 percent compared to before the heating period. On July 9, a picture showed that the removal procedure was completed successfully, which was announced on July 23 (Press release).

2003

October 10 - The Cassini science team announced the results of a test of Einstein's theory of gravity, using radio signals from the Cassini probe. The researchers observed a frequency shift in the radio waves to and from the space craft, as those signals traveled close to the Sun. Past tests were in agreement with the theoretical predictions with an accuracy of one part in one thousand. The Cassini experiment improved this to about 20 parts in a million, with the data still supporting Einstein's theory.

2004

February 27 - A new, high-resolution picture of Saturn taken by Cassini on February 9 was released, and it was noted that mission scientists were puzzled by the fact that no "spokes" in Saturn's ring are visible. These dark structures in the "B" section of the ring had been discovered in pictures taken by the Voyager probe in 1981. (See Press Release Image) Another picture, in infrared light, taken on February 16 shows cloud height differences and the same disturbance visible throughout the 1990s in Hubble Space Telescope images.

March 12 - Pictures taken February 23 do show a feature discovered by Voyager: Clumps in the outer "F"-ring. What could not be ascertained at the time, was the exact lifetime of these clumps, and it is hoped that Cassini will provide conclusive data about this question. The first set of pictures show a set of "clumps" moving along the "F" ring.

March 26 - The Cassini science team published a first sequence of pictures of Saturn showing clouds moving at high speed around the planet. Using a filter to better see water haze on top of the dense cloud cover, motions in the equatorial and southern regions are clearly visible. (Large GIF sequence file from JPL). The pictures were taken during the days from February 15 to February 19.

April 8 - The first "long-term" observation of cloud dynamics in Saturn's atmosphere were published by mission scientists. A set of pictures shows two storms in the southern latitudes merge during a period from March 19 to March 20. Both storms had a diameter of about 1,000 km (620 mi) before they merged.

April 12 - 40,000,000 kilometers from Saturn at 19:35:12 UT.

April 15 - NASA announced today, that two moons discovered by Voyager 1 were sighted again by Cassini in pictures taken on March 10: Prometheus and Pandora.

'F' Ring and shepherd moons

These are no ordinary moons, but their gravitational effects on the "F" ring led scienties to call them "shepherd moons." They fascinate all researchers interested in the dynamic of the ring system, because their orbits are close enough that they interact with each other in a "chaotic" manner. They have a history of defying predictions of their orbits. One of Cassini's missions will be to monitor the movements of these bodies closely.

May 4 - Cassini will be 30,000,000 km from Saturn at 02:57:31 UT in SCET. It will be 1,340,742,615 km from the Sun. The speed related to Saturn will be 5466 m/s. The speed related to the Sun will be 5570 m/s.

May 19 - Cassini will enter the Saturn system at 10:54:58 UT in SCET. At that time, the gravitational pull of Saturn begins to overtake the influence of the Sun. The spacecraft will be 22,716,387 km from Saturn and 1,343,723,216 km from the Sun. The speed related to Saturn will be 5541 m/s. The speed related to the Sun will be 5478 m/s.

May 25 - Cassini will be 20,000,000 km from Saturn at 02:38:02 UT in SCET. It will be 1,344,809,089 km from the Sun. The speed related to Saturn will be 5581 m/s. The speed related to the Sun will be 5435 m/s.

May 27 - The Phoebe approach TCM (Trajectory Correction Maneuver) takes place at ~22:30 UTC.

June 11 - Cassini's flyby of Phoebe at 19:32 UT in SCET at 1997 km distance.

July 1 - Saturn Orbit Insertion, which begins at 01:12 UT in SCET and ends at 02:48 UT.

2005

January 14 - Huygens enters Titan's atomsphere at 03:04 UT and lands on its surface in two or more hours.