From: Walter Watts (wlwatts@home.com)
Date: Tue Jan 15 2002 - 23:45:35 MST
Camera on Galileo to Take Last Pics
01/15/2002 4:20 PM EST
By ANDREW BRIDGES
LOS ANGELES (AP) - Since 1989, the camera on NASA's Galileo spacecraft
has captured a comet slamming into Jupiter, volcanoes erupting on one of
its moons and the first known moon orbiting an asteroid.
On Thursday, the camera will snap its last pictures. Galileo will make
its final flyby of one of Jupiter's major moons when it sweeps within 62
miles of Io.
The mission budget does not cover any further pictures.
Galileo will continue making other scientific observations until
September 2003, when the $1.4 billion spacecraft is expected to slam
into Jupiter in a spectacular finale. But the 70 photographs to be
transmitted to Earth over the next three months will be the last.
They will be a bittersweet reminder of a mission that was supposed to
provide scientists - and the world - with motion picture-like images of
Jupiter's vibrant atmosphere. Because of computer glitches and other
problems, Galileo never did produce the movie-quality images, but it
still provided stunning and scientifically valuable pictures.
During 32 orbits of Jupiter, Galileo studied the planet-size moons
Ganymede, Callisto, Europa an d Io.
Among its discoveries was evidence of liquid oceans beneath the surfaces
of Europa and Callisto that could harbor life. The spacecraft also kept
tabs on some of the dozens of hot, active volcanoes on Io.
In all, Galileo has returned about 14,000 images to Earth.
"It will be sad when we get to the end, but at the same time, looking
back at its history, you can be quite proud of the mission," Eilene
Theilig, Galileo project manager at NASA's Jet Propulsion Laboratory.
The spacecraft was launched in 1989 from the space shuttle Atlantis and
arrived in orbit around Jupiter six years later.
Originally, Galileo was to have used its high-gain antenna to zip data
back to Earth at 134 kilobits per second - more than twice the rate of a
typical home dial-up modem. Scientists hoped to capture hundreds of
thousands of images of Jupiter's atmosphere, stitching them together to
create elaborate movies.
Instead, the antenna jammed during its deployment in 1991, forcing
scientists to rely on the probe's low-gain antenna and its pokey rate of
160 bits per second. The glitch was compounded by radiation damage to
the camera and other spacecraft components.
Still, the camera piled up the images.
In 1993, Galileo captured the asteroid Ida at close range, allowing
scientists to discover that the space rock had a tiny moon of its own,
which they named Dactyl. A year later, Galileo watched as fragments of
the comet Shoemaker-Levy 9 slammed into Jupiter and exploded in its
atmosphere.
During Thursday's flyby, Galileo will make its closest pass yet to any
of Jupiter's moons. Its camera should be able to capture features on
Io's surface as small as 33 feet across. It will also snatch the first
peek at the moon's Jupiter-facing hemisphere since the Voyager mission
in 1979.
--- On the Net: http://www.jpl.nasa.gov/galileo/index.html -- Walter Watts Tulsa Network Solutions, Inc. "To err is human. To really screw things up requires a bare-naked command line and a wildcard operator."
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