CASSINI-HUYGENS MISSION OBJECTIVES    ================================== The Cassini-Huygens mission will accomplish a variety of scientificobjectives en route to and at Saturn [JPL D-5564]. While en route to Saturn, Cassini performed three sets of GravitationalWave Experiments (GWEs), each scheduled near opposition and each lastingapproximately 40 days.  During these observations, Cassini acted as a pointmass which would be perturbed by propagating gravitational waves resultingfrom sudden destruction (or creation) of large masses in the generaldirection of the spacecraft-to-Earth line. While en route to Saturn, Cassini was also used in two Solar ConjunctionExperiments (SCEs), each lasting approximately 30 days.  The objectives ofthese observations was to test general relativity and to improve ourunderstanding of the solar corona. The general scientific objectives of the Cassini mission at Saturn were toinvestigate the physical, chemical, and temporal characteristics of Titanand of Saturn, its atmosphere, rings, icy satellites, and magnetosphere.These are listed more specifically below: Saturn (Planet) Objectives.-------------------------- a) Determine temperature field, cloud properties, and composition of theatmosphere of Saturn. b) Measure the global wind field, including wave and eddy components;observe synoptic cloud features and processes. c) Infer the internal structure and rotation of the deep atmosphere. d) Study the diurnal variations and magnetic control of the ionosphere ofSaturn. e) Provide observational constraints (gas composition, isotope ratios, andheat flux, etc.) on scenarios for the formation and the evolution of Saturn. f) Investigate the sources and the morphology of Saturn lightning, SaturnElectrostatic Discharges (SED), and whistlers.  Titan Objectives.---------------- a) Determine abundance of atmospheric constituents (including any noblegases), establish isotope ratios for abundant elements, constrain scenariosof formation and evolution of Titan and its atmosphere. b) Observe vertical and horizontal distributions of trace gases, search formore complex organic molecules, investigate energy sources for atmosphericchemistry, and model the photochemistry of the stratosphere, studyformation and composition of aerosols. c) Measure winds and global temperatures; investigate cloud physics,general circulation, and seasonal effects in Titan's atmosphere; search forlightning discharges. d) Determine the physical state, topography, and composition of thesurface; infer the internal structure of the satellite. e) Investigate the upper atmosphere, its ionization, and its role as asource of neutral and ionized material for magnetosphere of Saturn.  Ring Objectives.--------------- a) Study configuration of the rings and dynamical processes (gravitational,viscous, erosional, and electromagnetic) responsible for ring structure. b) Map composition and size distribution of ring material. c) Investigate interrelation of rings and satellites, including embeddedsatellites. d) Determine dust and meteoroid distribution in the vicinity of the rings. e) Study interactions between the rings and Saturn's magnetosphere,ionosphere, and atmosphere.  Icy Satellite Objectives.------------------------ a) Determine the general characteristics and geological histories of thesatellites. b) Define the mechanisms of crustal and surface modifications, bothexternal and internal. c) Investigate the compositions and distributions of surface materials,particularly dark, organic rich materials and low melting point condensedvolatiles. d) Constrain models of the satellites' bulk compositions and internalstructures. e) Investigate interactions with the magnetosphere and ring systems andpossible gas injections into the magnetosphere.  Magnetosphere Objectives------------------------ a) Determine the configuration of the nearly axially symmetric magneticfield and its relation to the modulation of Saturn Kilometric Radiation(SKR). b) Determine current systems, composition, sources, and sinks ofmagnetosphere charged particles. c) Investigate wave-particle interactions and dynamics of the daysidemagnetosphere and the magnetotail of Saturn and their interactions with thesolar wind, the satellites, and the rings. d) Study the effect of Titan's interaction with the solar wind andmagnetospheric plasma. e) Investigate interactions of Titan's atmosphere and exosphere with thesurrounding plasma.