When Mars Pathfinder Web master David Dubov and his colleagues at the Jet Propulsion Laboratory began thinking about the mission's Web site presence on the Internet, they anticipated heavy usage of about 25 million hits a day. They planned accordingly--adding servers, arranging for more than 20 mirror sites and increasing computer capacity.
Few, however, could have anticipated the colossal interest that the highly successful, and accessible, mission would engender on the Net and World Wide Web.
Since the lander and its precious cargo, the Sojourner rover, touched down on the Martian surface on Independence Day, the main Pathfinder site at JPL and its worldwide network of mirror sites have averaged about 40 million to 45 million hits each day.
"The hits on our Internet [site] have been unbelievable," team project manager Tony Spear said at a news conference Friday. "I just wish I had charged everyone a dollar," he joked.
July 7 "was our highest day, close to 80 million hits worldwide. It's one of the biggest Internet events. It certainly is a NASA record," Dubov said.
Practically anyone with a computer, a mouse and a modem can download Mars images and study in detail a planet more than 100 million miles from Earth almost as soon as the scientists themselves see it.
"We're trying to get [the images] out once or twice a day. It's less ephemeral than television. You can sit there, take your time browsing through the sites, have a beer and look at the surface of Mars," Dubov said.
By logging on to the Mars Pathfinder site, the visitor is treated to a cornucopia of images and information. Rocks and vistas familiar to television watchers appear on the computer screen in astonishing detail. There are links to Mars weather conditions, rover status, science and engineering data and live audio and video feeds from NASA-TV.
There is also a section devoted to students and their teachers. Here the choices include opportunities for kids to learn about Mars and space science, see what other students in far-flung locales have done, interact with members of the Mars scientific teams and even download and build Pathfinder models.
"Teachers have said that this is so wonderful for students to look at, information that's not even in any textbook, information that's immediately available in plain English," Dubov said.
Their work is part of what NASA administrator Dan Goldin has characterized as a "virtual presence" on Mars, Dubov said.
"He wanted, through the Internet and television coverage, to have the public join us there on Mars," he said.
Rich Pavlovsky, JPL Web master, and Kirk Goodall, Pathfinder Web engineer, are the other members of the Web site team.
"Two years ago we had the Galileo [mission] to Jupiter that was a big Internet event for the JPL home page. I think we got about 5 million hits that week," Pavlovsky said.
But with so many more people on the Internet today, "it's almost unfair" to make comparisons, he said.
"If we were to do this five years ago, the only people to get it would be universities and government. They were the only people on the Internet," Pavlovsky said.
Advanced technology also contributed to the wide availability and popularity of the Mars mission.
"This enables us to get to a whole new audience by communicating the excitement and sheer joy in exploring [space]," Dubov said.
"Being able to see these images almost as soon as we see them at JPL gives people a sense of participating with us. If we can do that, the whole space program benefits, not just here, but all over the world," he said.
The Mars Pathfinder site can be found at
Some mirror sites can be found at: