A saucer-shaped, gold-colored space probe nearly 3 meters (9 feet) in diameter has been delivered to NASA by the European Space Agency and is now being readied for testing on the graphite and aluminum framework of the Saturn-bound Cassini spacecraft.
The engineering model of Europe's Huygens probe, delivered to NASA's Jet Propulsion Laboratory, is twin to the actual flight model that is destined to parachute to the exotic surface of Saturn's largest moon, Titan. The reflective fabric that blankets the probe will provide thermal and micrometeorite protection to the device in space. The flight model of the Huygens probe will be installed on the Cassini spacecraft at Cape Canaveral, FL, prior to launch on Oct. 6, 1997.
A second important delivery of European hardware for Cassini was received on July 21 with the arrival of Italy's specially tailored engineering model of the 10-meter (13-foot)-diameter high-gain telecommunications antenna. The antenna, provided by the Italian Space Agency, Agenzia Spaziale Italiana, will serve as the Cassini spacecraft's "voice box" and "ears," sending data back and receiving commands from Earth during the 11-year-long mission. The multi-channel antenna is also a crucial part of several of Cassini's scientific investigations, including imaging radar and gravity experiments.
"With these major deliveries from our European partners, we remain on schedule to meet our Saturn launch date," said Cassini project manager Richard J. Spehalski at JPL. "These critical hardware contributions enable us to proceed into technical qualification of the Cassini orbiter and Huygens probe hardware." Mated together, the probe and orbiter hardware will undergo months of structural and space environmental testing.
The Cassini spacecraft will fly a looping, seven-year-long course, swinging twice past Venus and once past Earth and Jupiter to reach Saturn, about 1.4 billion kilometers (nearly 1 billion miles) away. Once there, Cassini will release the Huygens probe, with six instruments onboard, to explore Titan's atmosphere and surface. Over the course of its two-and-a-half hour parachute descent to Titan's surface, the Huygens probe is expected to return a wealth of data to the Cassini orbiter for relay back to Earth.
Titan is a moon the size of a small planet. Its chemically complex atmosphere is primarily nitrogen and is rich in hydrocarbons, resembling the early atmosphere of Earth. Lakes or small oceans of liquid ethane may surround a continent-size surface feature on Titan recently discovered by scientists using the orbiting Hubble Space Telescope. Studies of Titan by the Huygens probe will not only provide insight into the history and status of this unique body, but will also provide clues to the early history of Earth.
With the Huygens probe portion of the mission completed, the Cassini spacecraft itself will remain in orbit around Saturn to return nearly four years of scientific information about the planet, its rings, moons and magnetic environment. Cassini will also conduct numerous flybys of Titan to gather more information about its atmosphere and global surface characteristics. An imaging radar instrument that can see through Titan's opaque atmospheric haze will gather data to produce photograph-like images of the surface.
Many of Saturn's moons will be targets of intensive study, as will the dynamics, structure and make-up of the planet's rings. Saturn itself, made up mostly of hydrogen and helium, will be characterized in detail, and Cassini will study how charged particles from the Sun interact with the large, complex magnetic environment that envelops Saturn.
The Huygens Probe is named for 17th-century Dutch scientist Christiaan Huygens, who discovered Titan in 1659. The Cassini spacecraft is named for Italian-French astronomer Jean-Dominque Cassini, who discovered four more of Saturn's moons and in 1675 found the gap -- now called the Cassini Division -- that separates two of Saturn's more prominent rings.
The Cassini mission is an international project jointly managed by NASA, the European Space Agency and Agenzia Spaziale Italiana. Contractors, academic institutions and space and science agencies from 17 countries are participating in the mission.
The overall Cassini mission is managed by the Jet Propulsion Laboratory for NASA's Office of Space Science, Washington, D.C.
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