  
The Cassini-Huygens Mission to Saturn (circa 1995)
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Overview and Objectives | Benefits of the Cassini-Huygens Mission | Saturn Orbiter
Huygens: Robotic Lander | Titan: A Primordial Earth | Cassini/Huygens Gallery
Benefits of the Cassini Mission
Technology Utilization Benefits
Challenging scientific enterprises routinely result in technology advances, which are applicable to other, unrelated fields. Project planning and preliminary research and development activities of the mission already have resulted in several significant technological innovations of direct benefit to government agencies, industry business, and environmental regulation.
Technology developed and qualified for space flight by or for the Cassini project is being adopted by the new "faster, better, cheaper" space science projects, in some cases at a discount directly attributable to Cassini, enabling the development of a new class of low-cost, high-efficiency spacecraft.
The large investment in Cassini's hardware development and qualification is directly benefiting not only space science missions, but commercial and defense space satellites as well.
Solid-State Recorder
One innovation developed for Cassini is a solid-state data recorder with no moving parts. The advanced X-ray Astrophysics Facility (AXAF) will use a solid-state recorder from the production line originally established for Cassini. The recorder has great potential for use in a variety of fields, from aerospace to the entertainment industry, and is expected eventually to find wide applicability in consumer electronics.
Powerful New Computer Chips
The Cassini Orbiter's main computer uses a novel design, which draws upon new families of electronic chips -- very high-speed integrated circuit (VHSIC) chips developed under a U.S. government/industry research and development initiative for dual-use technology. The Cassini application GVSC 1750A computer is the first civilian spacecraft application of this technology.
Powerful new radiation-hardened Application-Specific Integrated Circuit (ASIC) parts have also been developed for Cassini; each component replaces a hundred or more traditional chips. This has allowed the development of a data system for Cassini which is 10 times more powerful than the Galileo/Magellan designs, but less than one-third the mass and volume.
Discovery missions Mars Pathfinder and NEAR are now planning to use these chips directly off the Cassini production line.
Micro-Miniature Radio Receiver
The Cassini Project has developed a low mass, low power, radiation-hardened X-band radio receiver. This radio receiver will enable the NEAR and MESUR missions to meet their performance requirements. Both of these Discovery missions will have their radio receivers built on the Cassini product line.
Solid-State Power Switch
The Cassini project combined the current switching characteristics of the Metal Oxide Semiconductor Field-Effect Transistor (MOS FET) with its (ASOC) design to provide an innovative solid-state power switch which will eliminate rapid fluctuations (called transients) that usually occur with conventional power switches. This should result in significantly improved component lifetime and efficiency, and is widely applicable to both industrial and consumer electric and electronic products.
Gyros
The first space version of a revolutionary new gyro with no moving parts will be used on Cassini. The Hemispherical Resonator Gyroscope was developed and produced by Delco/Hughes and will serve as Cassini's inertial reference units.
This new gyro promises greater reliability and less vulnerability to mechanical failure because it uses no moving parts. This more robust gyro may eventually be used on many new spacecraft. The Discovery mission NEAR has served as the base line for the Cassini gyro with a minimum amount of modification.
Resource Trading System
In response to its commitment to deliver the mission for a fixed price, the Cassini project has embarked on a new way of managing its science resources. A "Cassini Resource Exchange" was developed by Cassini Project planners to help resolve the conflicting electrical power, data rate needs, and cost of the spacecraft's science instruments and other subsystems.
The Cassini Resource Exchange has been utilized by California's South Coast Air Quality Management District (AQMD) in its RECLAIM program to facilitate the buying and selling of emissions allowances by regulated facilities to help achieve reductions in air pollution required by the U.S. government.
Illinois is similarly adapting the Cassini Resource Exchange to manage that state's volatile organic wastes. Vancouver, B.C. is seeking to adapt the system to help that city manage its air pollution. Arizona is looking into using the system to help determine allocations in its Central Arizona Water Project.
National Telecommunications and Information Administration (NTIA) and the Federal Communications Commission (FCC) have contracted with Caltech to use the Cassini system in auctioning wavelengths of the electromagnetic spectrum to personal communications industries; the Cassini system's algorithms and communications protocols served as the backbone for the Caltech demonstrations.
Scientific Benefits of the Cassini Mission
Cassini's mission is a four-year, close-up study of the Saturnian system, including the planet's atmosphere and magnetic field, its rings and several moons. The mission represents a rare opportunity to gain significant insights into major scientific questions about the creation of the solar system and the continuations that led to life on Earth, in addition to a host of questions specific to the Saturn system.
As the best-instrumented probe ever sent to another planet, Cassini will produce the most complete information about a planet system ever obtained.
Chief among the scientific goals is a thorough characterization of the large moon, Titan, a natural satellite thought to resemble a frigid primordial Earth.
Titan's Earth-like Atmosphere -- Like Earth, Titan has a nitrogen-rich atmosphere. Complex organic molecules make up the haze that clouds Titan's surface view. These molecules must eventually fall to the surface in the same way that organic molecules fell from Earth's sky at the time life originated on our planet. For this reason, understanding the chemistry of Titan's atmosphere may be key to understanding the evolution of early life on Earth.
Huygens Probe -- A large portion of Cassini's Titan studies will be accomplished by the European Space Agency's Huygens Probe, which will be released from the Orbiter to descend by parachute through Titan's opaque atmosphere. During this descent, instruments mounted on the probe will directly sample the atmosphere and determine its composition. The surface of Titan may be solid ice or rock, or it may hold shallow seas of liquid ethane or methane. In addition, it is possible that over billions of years, the rain of complex organic molecules has built up a deep, brownish-orange sludge on Titan's surface. The descending probe will gather data on this exotic landscape and could briefly return information, including images, directly from the surface.
Imaging Radar -- Other Titan studies will be carried out by imaging radar, which passes signals through clouds or atmospheric haze and showers the surface of its target with a swath of radar pulses. Imaging radar has been used to great advantage in mapping cloud-covered regions of the Earth where other mapping instruments cannot "see" the surface and was used on NASA's Magellan spacecraft to product a global terrain map of cloud-shrouded Venus.
Seeing the Magnetic Field -- The Applied Physics Laboratory at Johns Hopkins University has designed an instrument for Cassini to allow the first-ever imaging of a planet's magnetic field. The Magnetosphere Imaging Instrument (MIMI) will obtain images of the plasma and radiation surrounding Saturn and enveloping its moons, including Titan. MINI will observe the glow of Titan's exosphere due to the bombardment by high-speed protons trapped in Saturn's magnetic field. This pioneering investigation will open an new observations window in the study of planetary magnetic fields, including Earth's. Despite the spacecraft's long travel time to Saturn, Cassini is likely to produce the first image of any magnetosphere in the solar system.
Ring Particles, Colors and Waves -- Largely composed of ice particles ranging in size from sugar grains to small houses, slight color variations indicate the rings include some rocky material. A wide range of unexplained phenomena are seen in the rings, including various wave patterns, small and large gaps, clumping of material and small, so-called "moonlets" embedded in the rings.
Origin of the Rings -- Long-term close-up observations of the rings by Cassini will help resolve whether the rings are material left over from Saturn's original formation of whether they are the remnants of one or more moons shattered by comet or meteor strikes.
Disk Systems -- Applied to larger scale, disk-shaped systems, Cassini's detailed studies of Saturn's rings will provide important contributions to theories about the origin and evolution of the dust and gas from which the planets first formed. Additional studies of the Saturnian system as a microcosm may be applicable to examinations of even larger disk systems so common in the universe, including our own spiral galaxy the Milky Way.
Ring Viewing -- Cassini's arrival at Saturn is timed for optimum viewing of the rings, during a period when they will be well-illuminated by sunlight. Upon arrival at Saturn in 2004, the tilt of the ring plane will allow Cassini's instruments an unsurpassed view of the ring disk. Cassini will detect small moonlets inside the rings, determine the composition of the particles, determine the effects of magnetic field interaction with the rings and conduct intensive observations of ring dynamics.
Enceladus -- The Saturnian moon is made entirely of water ice with few indications of impact craters on its surface. Cassini will determine if Enceladus has some internal heat source that melts the ice enough to erase impact craters. It will search Enceladus for small, geyser-like volcanoes; some scientists suspect such volcanoes may shoot ice particles into space, where they are captured by Saturn's gravity and made part of the outer E-ring.
Iapetus -- The Saturnian moon is targeted for study because of it s unique surface: one-half is covered with a snow-bright substance while the other half is covered with material as dark as asphalt and thought to be complex organic material. Cassini will help determine the surface composition of Iapetus, discover the nature of the dark material and determine whether it came form within the moon or was deposited from another source.
Benefits of International Cooperation
Cassini is a cooperative venture of NASA, the European Space Agency and Italian Space Agency. Participation in the mission is a high priority for NASA's European partners and represents a foundation upon which future U.S.-European space science cooperation is being based.
The mission represents an opportunity for spacefaring nations to share in both the investment and scientific return of the most ambitious and challenging of exploration. Cassini's NASA-European partnership provides an example of a mission whose scope and cost would not likely be borne by any single nation but which is made possible through shared investment and participation.
A Unique R&D Capability
The Cassini project represents the world's only fully funded science probe to the outer planets. The mission is the next step in a highly productive, three-decade-old program of exploration of the solar system using robotic spacecraft. The project employs more than 3,000 individuals in science, technology, academia, business and industry in the U.S. In Europe, 14 nations are participating in the technological development of the Huygens Probe, and scientists from 12 European nations are members of Cassini's scientific team.
For the latest developments and news on the mission visit:
NASA - National Aeronautics and Space Administration
ESA - European Space Agency
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