Multispectral images of the lunar western limb and far side obtained from Galileo reveal the compositional nature of several prominent lunar features and provide new information on lunar evolution. The data reveal that the ejecta from the Orientale impact basin (900 kilometers in diameter) lying outside the Cordillera Mountains was excavated from the crust, not the mantle, and covers pre-Orientale terrain that consisted of both highland materials and relatively large expanses of ancient mare basalts. The inside of the far side South Pole-Aitken basin (>2000 kilometers in diameter) has low albedo, red color, and a relatively high abundance of iron- and magnesium-rich materials. These features suggest that the impact may have penetrated into the deep crust or lunar mantle or that the basin contains ancient mare basalts that were later covered by highlands ejecta.

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The Cassini-Huygens Program is an international science mission to the Saturnian system. Three space agencies and seventeen nations contributed to building the Cassini spacecraft and Huygens probe. The Cassini orbiter is managed and operated by NASA's Jet Propulsion Laboratory. The Huygens probe was built and operated by the European Space Agency. The mission design for Cassini-Huygens calls for a four-year orbital survey of Saturn, its rings, magnetosphere, and satellites, and the descent into Titan's atmosphere of the Huygens probe. The Cassini orbiter tour consists of 76 orbits around Saturn with 45 close Titan flybys and 8 targeted icy satellite flybys. The Cassini orbiter spacecraft carries twelve scientific instruments that are performing a wide range of observations on a multitude of designated targets. The Huygens probe carried six additional instruments that provided in-situ sampling of the atmosphere and surface of Titan. The multinational nature of this mission poses significant challenges in the area of flight operations. This paper will provide an overview of the mission, spacecraft, organization and flight operations environment used for the Cassini-Huygens Mission. It will address the operational complexities of the spacecraft and the science instruments and the approach used by Cassini-Huygens to address these issues. I. The Mission Saturn has fascinated observers for over 300 years. The only planet whose rings were visible from Earth with primitive telescopes, it was not until the age of robotic spacecraft that questions about the Saturnian system's composition could be answered. Previous robotic spacecraft encounters with Saturn were the flybys of Pioneer 11 in 1979, Voyager 1 in 1980, and Voyager 2 in 1981. Plans for a dedicated Saturn orbiter were begun in 1982 and became the Cassini-Huygens mission. Launched from Cape Canveral on October 15, 1997, the Cassini-Huygens spacecraft reached the Saturnian region in July 2004. After a seven-year, 2-billion mile voyage that included four gravity-assist planetary flybys, the Cassini orbiter entered Saturn's domain and began a four-year mission featuring 76 orbits around the ringed planet and its moons and deployment of the Huygens probe into Titan's atmosphere. The main scientific goals include measuring Saturn's huge magnetosphere, analyzing, from up close, the stunning ring system, studying Saturn's composition and atmosphere, as well as detailed, targeted observation campaigns of Titan and the other large satellites. The design of the Cassini primary mission involved trades between competing objectives. Science objectives at Saturn include investigations into atmospheric properties and composition, internal structure and rotation, and the ionosphere. The rings of Saturn are being observed for structure and composition, dynamical processes, interrelation between the rings and satellites, and the dust/micrometeoroid environment. The magnetosphere of Saturn is to be investigated for its dynamical configuration, particle composition, sources, and inter...

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