Cassini/Huygens Science Mission Set to Begin with Orbital Insertion at Saturn this Week

By Bob Moody (AOAS) and Gerrit Penning (ASSABFN)
UPDATE: July 1, 2004 Saturn Orbital Insertion a Success!
For the latest images, go to: http://saturn.jpl.nasa.gov/multimedia/images/latest/index.cfm

After a journey of seven years through the solar system, the Cassini spacecraft with its on-board Huygens probe, is set to arrive at Saturn this Wednesday/Thursday with a firing of the main engine for just over 100 minutes to slow it’s 50,000 mph speed by 1,300 mph to attain orbital insertion around the Ringed Planet. A slowing of it’s inertial speed will occur in stages to bring it into position for its scientific mission to study Saturn and its attendant moons, along with the release of the Huygens probe set for December 25, 2004. The Huygens probe will enter the thick atmosphere of Saturn’s largest moon Titan behind a sophisticated heat shield at a speed of nearly 44,000 mph in mid-January, 2005. After enduring temperatures of over 21,000 degrees Fahrenheit, the probe will release its main parachute at 900 mph at an altitude of about 110 miles above Titan’s surface, and then eject the protective heat shield. A separate drogue parachute will deploy at 85 miles altitude and carry the sophisticated probe down to the surface. The probe will take up to 1,100 pictures as it descends through the otherworldly atmosphere.

This mission to Saturn and Titan will bring untold wonders and mystery as it unfolds for the next three years of it’s planned mission. Barring accidents, the mission may then be extended and several more risky maneuvers may be added to further and/or enhance our findings to that point sometime in 2008-2009. Cassini may take a much closer look at the ring material by making another, even closer pass above the ring plane. Another risky option may be to leave the Saturnian system to visit an asteroid for close inspection, or maybe to some comet nucleus. Or, it might be allowed to make brief passes into the outer atmosphere of Titan, or even a mission ending plunge into the clouds of Saturn itself. The most certain thing about this mission is that it will reveal a world and it’s moons as no spacecraft ever has before, and the findings are sure to be dramatic and wonderful.

Here are a few quick facts regarding the mission:

• Launched: 15 October 1997
• Built by JPL (Cassini) and ESA (Huygens).
• 19 countries contributed specialties.
• The spacecraft weighs almost six tons and is two stories high.
• Cassini has 12 on-board science instruments and Huygens has 6. It is the most sophisticated interplanetary spacecraft ever built.
• On 1 July 2004, 3:12 in the morning (SAST), the orbital insertion maneuver will commence. The craft will move between the outer F and G ring of Saturn. Of all 4 years that it will orbit the Saturn system, Cassini will be closest the planet at this stage as it will ever get: 18 000 km away. It is a very important part of the mission and risky.
-The Huygens probe will jettison from Cassini on 25 December 2004 and arrive at Titan three weeks thereafter. It will travel by parachute for two hours through Titan's atmosphere and do scientific experiments. On the surface, the probe will last for only 3 to 30 minutes. Whether it will land on soil or in an ocean of methane is unsure, but the focus is not on the surface in any case.

Cassini's latest image

Other Links:

http://saturn.jpl.nasa.gov
www.esa.int/SPECIALS/Cassini-Huygens
http://ciclops.lpl.arizona.edu/ (photos)
http://www.nasa.gov/mission_pages/cassini/main/index.html

You may also want to subscribe to www.spaceflightnow.com for the latest news. As amateur astronomers around the world await these exciting days ahead, members of the Astronomical Society of South Africa Bloemfontein Centre and the Arkansas Oklahoma Astronomical Society will all have our fingers crossed and with prayers on our lips as we wait for a successful orbital insertion later this week. Once there orbiting Saturn, Cassini/Huygens will become the world’s mission, mankind’s mission to Saturn and Titan, and we'll be there to stay!