STORY WRITTEN FOR & USED WITH PERMISSIONPosted:
STORY WRITTEN FOR & USED WITH PERMISSIONPosted: October 26, 2004PASADENA, Calif. - NASA's Cassini spacecraft streaked by Saturn's smoggy moon Titan today, targeted to pass within just 750 miles of the planet-sized satellite to give scientists their first detailed glimpse of a world that, until now, has been shrouded in mystery.Moving through space at some 14,000 mph, Cassini made its closest approach to Titan at 12:44 p.m. EDT, using the moon's gravity to change its trajectory slightly for another Titan flyby Dec. 13.Today's encounter, the first of 45 Titan flybys planned over the course of Cassini's four-year primary mission, occurred while the $3 billion spacecraft was out of contact with flight controllers at the Jet Propulsion Laboratory in Pasadena, Calif.The high-gain dish antenna normally used to communicate with Earth was aimed instead at Titan for cloud-piercing synthetic aperture radar observations. Those images, along with other radar data and high-resolution visible, infrared and ultraviolet observations, should resolve long standing questions about Titan, including whether the moon harbors standing lakes or pools of liquid ethane and hydrocarbon sludge.But Cassini will not turn its high-gain antenna back toward Earth and begin playing back recorded data until late this evening. It will take those radio signals, traveling 186,000 miles per second, one hour and 14 minutes to reach NASA's Deep Space Network antennas some 826 million miles away.The first low-resolution pictures are expected to begin showing up around 9:40 p.m. High-resolution imagery will reach Earth starting around 12:51 a.m. Wednesday, with narrow-angle resolutions of a tenth of a mile per pixel. That will improve to 17 feet per pixel when the highest resolution pictures flow in around 2:40 a.m.Data playback will end at 5:22 a.m. and Cassini will make this orbit's closest approach to Saturn at 7:33 a.m.A timeline of major events that includes the number of images expected from the narrow- and wide-angle cameras (in EDT; resolution in statute miles) is available .Along with collecting priceless imagery and data about Titan, today's encounter, known as Titan A or TA for short, also collected critical atmospheric data that will be used to determine just how close Cassini can safely pass during upcoming flybys.That same data also will shed light on what Cassini's Huygens probe can expect when it slams into the atmosphere of Titan Jan. 14.Built by the European Space Agency, Huygens will descend by parachute all the way to the moon's surface, using a suite of instruments to probe its environment. Data will be relayed back to Earth by Cassini, which will be flying past at the same time.The density of Titan's atmosphere, however, is a critical factor in the Huygens' descent. The probe is scheduled to be released from Cassini on Christmas Eve and depending on what today's TA flyby data show, engineers could elect to make slight changes to its trajectory.The data were considered so vital that engineers programmed playback through two DSN ground stations to ensure successful capture.Along with characterizing the moon's atmosphere, Cassini also was programmed to photograph the Huygens landing site at a resolution of .62 miles per pixel, hopefully providing insights into what the probe can expect when it reaches the surface in January.Cassini braked into orbit around Saturn the night of June 30, firing its main engine for a nerve-wracking 96.4 minutes. Another long rocket firing in late August raised the low point of Cassini's orbit and set the stage for an extended voyage of discovery.Equipped with state-of-the-art telescopes, an imaging radar system and a battery of other powerful instruments, Cassini will spend at least four years orbiting the sixth planet from the sun, studying its rings in unprecedented detail, making high-resolution movies of its windy atmosphere, charting its magnetic field and mapping a host of icy moons.Titan will get special treatment. Bigger than Mercury and Pluto, Titan is the only moon in the solar system with a thick atmosphere, one in which hydrocarbons fall as rain and liquid ethane pools on its ultra-cold surface. Or so astronomers believe.TITAN FACTS AND FIGURES Discovered by...........Christiaan Huygens, 1655Mass (Earth=1)..........0.02259Radius..................1,600 milesDiameter................3,200 milesDistance from Saturn....745,000 milesRotation period.........15.94 daysOrbital period..........15.94 daysOrbital inclination.....0.33 degreesAtmospheric pressure....1.6 times Earth'sTemperature.............-290 FahrenheitDaylight at surface.....1/1000 the intensity of sunlight on EarthIn a pre-launch news conference seven years ago, Jonathan Lunine, a University of Arizona physicist and a member of the Cassini science team, provided an educated guess about what today's flyby and the Huygens probe might reveal."Imagine a world that's smaller than Mars and bigger than the planet Mercury, where the air is four times denser at its surface than the air in this room and the surface pressure is about the same as you'd experience at the bottom of a neighborhood swimming pool," he said. "On that world, the distant sun is never seen and at high noon, things are no brighter than a partly moonlit night on the Earth."Because of its great distance, the cold is so enormous that water is always frozen out of the atmosphere. Nitrogen is nearly so, but not quite. And the simplest organic molecule, methane, is there to take the place of water as a cloud former, possibly a rain maker and maybe even the stuff of lakes or seas of hydrocarbons."The methane is lofted hundreds of miles above the surface of this world," Lunine said before Cassini's launch in 1997. "It's cracked open by sunlight and cosmic rays and a menagerie of more complicated organics is produced from the methane and these then float down to the surface to accumulate over time, perhaps to depths of hundreds of meters or more. Volcanism and impacts shape the surface and provide energy to make ever more complex organic molecules in a planet-wide tapestry that is an organic chemist's dream."What I have described to you is Titan, the second largest moon in the solar system, nearly the largest. It was partly revealed to us by Voyager 1 in 1980. Through its many instruments, Voyager discovered and characterized a dense atmosphere around this cold world. Yet ... Voyager's cameras could not penetrate the organic haze and so we still do not know what awaits Cassini-Huygens at the end of its journey."But in the years since Cassini's launch, optical and radar observations from Earth have given scientists at least a hint of what the spacecraft might find. Scientists are convinced lakes or small oceans of liquid hydrocarbons exist on Titan, but not a globe-spanning sea. One way or the other, Cassini and Huygens should resolve the matter."Titan is almost certainly not the home of life today," Lunine said. "But the organic chemical cycles that go on may constitute a chemical laboratory for replaying some of the steps that led to life on Earth. Titan is in some ways the closest analogue we have to the Earth's environment before life began and this makes Titan very important."Ares 1-X PatchThe official embroidered patch for the Ares 1-X rocket test flight, is available for purchase.Apollo CollageThis beautiful one piece set features the Apollo program emblem surrounded by the individual mission logos.Expedition 21The official embroidered patch for the International Space Station Expedition 21 crew is now available from our stores.Hubble PatchThe official embroidered patch for mission STS-125, the space shuttle's last planned service call to the Hubble Space Telescope, is available for purchase. | | | | 2014 Spaceflight Now Inc.Cassini getting ever closer to colorful Saturn CICLOPS/SPACE SCIENCE NEWS RELEASEPosted: June 3, 2004As Cassini coasts into the final month of its nearly seven-year trek, the serene majesty of its destination looms ahead. The spacecraft's cameras are functioning beautifully and continue to return stunning views from Cassini's position, 1.2 billion kilometers (750 million miles) from Earth and now 15.7 million kilometers (9.8 million miles) from Saturn. Credit: NASA/JPL/Space Science InstituteDownload larger image version In this narrow angle camera image from May 21, 2004, the ringed planet displays subtle, multi-hued atmospheric bands, colored by yet undetermined compounds. Cassini mission scientists hope to determine the exact composition of this material. This image also offers a preview of the detailed survey Cassini will conduct on the planet's dazzling rings. Slight differences in color denote both differences in ring particle composition and light scattering properties. Images taken through blue, green and red filters were combined to create this natural color view. The image scale is 132 kilometers (82 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Office of Space Science, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colorado. Ares 1-X PatchThe official embroidered patch for the Ares 1-X rocket test flight, is available for purchase.Apollo CollageThis beautiful one piece set features the Apollo program emblem surrounded by the individual mission logos.Expedition 21The official embroidered patch for the International Space Station Expedition 21 crew is now available from our stores.Hubble PatchThe official embroidered patch for mission STS-125, the space shuttle's last planned service call to the Hubble Space Telescope, is available for purchase. | | | | 2014 Spaceflight Now Inc.Cassini 'go' for Saturn orbit insertion burn BY WILLIAM HARWOOD Nike Free SlippersNike Hiroshi Fujimoto Slippers