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http://www.zwire.com/site/news.cfm?newsid=12244702&BRD=1395&PAG=461&dept_id=216620&rfi=6 Seven years later, Cornell probe reaches ringed planet
Cornell's Space Sciences Building (SSB) held its latest open house on the evening of Wednesday, June 30, inviting the public to witness a historic space event: The first orbiting of Saturn by a space probe from Earth.
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: Wed Jul 07 2004 - 09:17:44 PDT
By: Larry Klaes July 07, 2004
First it was the two rovers planted on the surface of Mars just weeks apart last January. Now Cornell can claim another world being explored by their scientists and instruments: The Ringed Planet, Saturn.
The vehicle, named Cassini after the Seventeenth Century Italian-French astronomer Jean Dominique Cassini, has spent the last seven years traveling through interplanetary space to reach the second largest planet in the Solar System. Only three other probes have visited Saturn, all of them flyby missions, the last in 1981.
Most of the university's scientists involved with Cassini were at the Jet Propulsion Laboratory (JPL) in Pasadena, California. A number of graduate students working on the mission watched the space robot's orbital insertion live displayed on large screens in several rooms at the SSB, courtesy of NASA Television.
As Cassini barreled towards Saturn at speeds of up to 70,000 miles per hour, the probe fired its braking engine for 96 minutes to slow itself enough to be captured by the planet's massive gravity to go into a wide orbit about the planet.
Mission controllers back on Earth had Cassini use its large communications antenna to serve as a shield as the probe conducted its braking maneuvers. This protected the vehicle from being hit and possibly damaged by any stray ring particles. It also kept Cassini from relaying data directly back to our planet.
However, the probe did record a good deal of valuable data as it went by Saturn closer than it ever will again during its four year main mission. The priceless information was eventually sent to Earth in the wee hours of the morning. Among many things, the data and images revealed new complexities in the rings never seen before.
Finally, at 12:10 a.m. EDT, a JPL mission controller announced that Cassini had stopped its engine burn as scheduled and had become the "first captured object around Saturn tonight."
Matija Cuk, a member of Cornell astronomer Joseph Burns's Cassini imaging system team, expressed a strong interest in the enigmatic ring "spokes" first seen by the two Voyager probes during their missions to Saturn in the early 1980s.
Strangely so far, the electronic eyes of Cassini have not witnessed these spokes, which may be dust particles floating above the main rings. Cuk thinks this perceived absence is due to the "flight angle of Cassini, or the way the light scatters off the ring particles." Cassini is certain to solve this mystery during its mission.
In addition to the rings, Cassini will explore many of the 31 known moons of Saturn, particularly the planet's largest, Titan. Covered in a thick orange haze, Titan has only given hints of what lies beneath those alien clouds. However, scientists hope to finally have this veil lifted by next January, when the Huygens probe Cassini has been carrying on its side becomes the first vessel to land on that moon.
As Huygens descends for nearly three hours in Titan's dense atmosphere, it will return data on its composition and panoramic images of its surface. One big mystery of this mission is what kind of surface Huygens will encounter. It has been long speculated that Titan is covered in seas and lakes of liquid hydrocarbons. Huygens may end up floating in one of those alien seas.
For more on Cassini and Saturn, see saturn.jpl.nasa.gov/ <http://www.zwire.com/site/saturn.jpl.nasa.gov/>
