NEW YORK -- Think of the Library of Congress's entire print collections - and then some - to get an idea of how much data space enthusiasts have downloaded from NASA's Web sites this week.
Visitors had obtained more than 34.6 terabytes of images, video and other information as of Friday afternoon, the bulk related to the Mars rover Spirit. By some estimates, all the words in every book in the Library of Congress total 20 terabytes.
So far, the National Aeronautics and Space Administration has posted all raw images from Spirit, some within a half-hour of the data reaching Earth. At least 10 to 30 images are expected daily, with some even available in 3-D.
NASA also created panoramic views by piecing several images together and plans interactive features in which viewers control the view with a mouse (sorry, but you won't be able to control the spacecraft's camera directly).
Once the rover begins moving, NASA plans video summaries at least weekly by combining still images. For now, video is largely limited to animation of the spacecraft's journey, documentary-style clips and streaming of the NASA TV cable channel.
The European Space Agency had planned similar offerings from Beagle 2, the British-built probe that has not been heard from since it left the Mars Express mother ship in mid-December. Europeans still plan to offer images from the mother ship within a month.
The NASA sites have received 1.7 billion hits, or requests for information, since the morning of Spirit's landing Saturday. That averages to 260 million hits daily, eclipsing traffic for the 1997 Mars Pathfinder mission, the Hubble Space Telescope and recent visits to Jupiter and comet Wild 2.
"Mars has always occupied kind of its own special place in people's imagination," said Brian Dunbar, NASA's Internet services manager.
Traffic peaked Monday, when the sites got more than 400 million hits. By comparison, Pathfinder got 47 million on the busiest day, and the shuttle Columbia disaster on Feb. 1 produced 75 million hits.
More than 13 million unique computers have visited the sites at some point since Saturday, NASA estimates.
To handle the Mars traffic, NASA is paying $1.5 million to eTouch Systems Corp., Speedera Networks Inc. and Sprint Corp. beyond the $3.5 million it pays them a year to handle NASA's more popular Web sites, said Jeanne Holm, NASA's Web portal manager.
As part of the deal, Speedera is reproducing NASA's Web sites on thousands of computers in the United States, Germany, the United Kingdom, China, India, Australia and more than a dozen other countries. Visitors automatically get the fastest available connection.
"We wanted to make sure people in different parts of the world wouldn't get an inconsistent experience," said Ajit Gupta, founder and chief executive of Speedera, which also handles Web content distribution for anti-virus companies and Fox's "American Idol."
During Pathfinder, NASA persuaded Sun Microsystems Inc., Cornell University and nearly two dozen other institutions to donate Internet capacity and host mirrors of the sites.
"It was a different Internet world then, when dot-coms were doing well and everybody was happy to pitch in," Holm said.
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