Cassini-Huygens is one of the most ambitious missions ever launched into space. Loaded with an array of
powerful instruments and cameras, the spacecraft is capable of taking accurate measurements and
detailed images in a variety of atmospheric conditions and light spectra.
Two elements comprise the spacecraft: The Cassini orbiter and the Huygens probe. In 2004, Cassini-Huygens
reached Saturn and its moons. There the spacecraft has begun to orbit around the system for four
years, beaming home valuable data that will help us understand the vast Saturnian region. Huygens entered
the murky atmosphere of Titan, Saturn's biggest moon, and descended via parachute onto its
surface.
Cassini-Huygens is a three-axis stabilized spacecraft
equipped for 27 diverse science investigations. The Cassini orbiter has 12 instruments and the Huygens
probe had six. The instruments often have multiple functions, equipped to thoroughly investigate all
the important elements that the Saturn system may uncover. The spacecraft communicates through one
high-gain and two-low gain antennas. It is only in the event of a power failure or other such emergency
situation, however, that the spacecraft will communicate through one of its low-gain antennas, known as LGA-1.
Three Radioisotope Thermoelectric Generators -- commonly referred to as RTGs -- provide power for the
spacecraft, including the instruments, computers, and radio transmitters on board,
attitude thrusters, and reaction wheels.
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Cassini-Huygens Spacecraft with "almost human" features
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In some ways, the Cassini spacecraft has senses better than our own. For example, Cassini can "see" in
wavelengths of light and energy that the human eye cannot. The instruments on the spacecraft can "feel"
things about magnetic fields and tiny dust particles that no human hand could detect.
The science instruments can be classified in a way that can be compared to the way human senses operate.
Your eyes and ears are "remote sensing" devices because you can receive information from remote objects
without being in direct contact with them. Your senses of touch and taste are "direct sensing" devices.
Your nose can be construed as either a remote or direct sensing device. You can certainly smell the
apple pie across the room without having your nose in direct contact with it, but the molecules carrying
the scent do have to make direct contact with your sinuses. Cassini's instruments can be classified as
remote and microwave remote sensing instruments, and fields and particles instruments--these are all
designed to record significant data and take a variety of close-up measurements.
The remote sensing instruments on the Cassini Spacecraft can calculate measurements from a great
distance. This set includes both optical and microwave sensing instruments including cameras,
spectrometers, radar and radio.
The fields and particles instruments take "in situ" (on site) direct sensing measurements of the environment
around the spacecraft. These instruments measure magnetic fields, mass, electrical charges and densities
of atomic particles. They also measure the quantity and composition of dust particles, the strengths of
plasma (electrically charged gas), and radio waves.
