Atthiswriting the Cassini spacecraft has ?redits engine and successfully inserted itself andits precious cargoof scienti?c instruments into orbit, the ?rst step of its exploration of the Saturnian system. The suspense is not over, however. While excitingimages of therings have been captured,anexotic composition of Phoebe sensedby themapping spectrometer and unexpectedpanoply of magneticwaves andplasma dynamics encountered on the incoming trajectory andinitial orbit, the Huygensprobeisstillonboardandthe?rstclose?ybyofTitanhasnottakenplace. Not until Christmas Day will the probe bereleased.Navigators are still checking theircalculations,worryingaboutknownunknownslikethemassofSaturn'smoons that could cause ever so small a deviation from the planned trajectory of the probe. Theorbiter investigators are also anxious but theyget their taste of Titan earlier, on October 26.Howwell will theydetect the surface? How thickisthe atmosphere? Does Titan haveamagnetic?eld?Isthere lightninginthe atmosphere of Titan? While terrestrial and HubbleSpace Telescope pictures have improvedgreatly over the years, they cannot match the resolution obtainable from orbitabout theplanet, and much of the data issimply unobtainablewithout direct insitu sensing. Volume 1 of this three volume set described the Cassini/Huygens mission, its scienti?c objectives and the Huygens probethat will soon enter theTitan at- sphere. Volume 2 described the insitu investigations on theorbiter. In this, the third and ?nal volume of the compendium, we describethe remote sensing inv- tigations: radioscience, radar, visibleandinfrared spectroscopy, thermalinfrared studies, ultraviolet spectroscopy and visible imagery.
The joint NASA-ESA Cassini-Huygens mission is a splendid example of how international cooperation can produce a wealth of scientific return that could not be afforded by the programs of any partner alone. ESA contributed the Titan atmosphere entry probe and NASA the orbiter spacecraft, the launch, and operations. Various national agencies contributed to the payloads of both the orbiter and the entry probe. Cassini will return much more information than the Galileo mission. While Saturn is further from the Sun than Jupiter, with less illumination and a colder environment, Saturn's weaker radiation belt permits longer periods of observation close to Saturn than were possible with Galileo at Jupiter. Cassini provides shorter period orbits, closer images of the rings and the atmosphere, and many more satellite encounters, in fact 44 encounters with Saturn's largest moon, Titan, in the first four years in orbit. This greater number of observations provides a rich scientific bonanza for the remote sensing instruments on Cassini. This book is the third and last volume of this compendium on the Cassini-Huygens mission.
This volume describes the remote sensing investigations on the Cassini orbiter: radio science, radar, visible and near infrared spectroscopy, far infrared spectroscopy, ultraviolet spectroscopy, and visible imagery. This book is of interest to all potential users of the Cassini-Huygens data, to those who wish to learn about the planned scientific return from the Cassini-Huygens mission, and those curious about the processes occurring on this most fascinating planet.
