Mission to Mars reveals need for more bandwidth

NASA officials are calling the unprecedented volume of Internet traffic received Dec. 3 by the main Mars Polar Lander World Wide Web site a "good wake-up call" for the space agency.

On the day of the expected landing, the 20 mirror sites coordinated by NASA's Jet Propulsion Laboratory, Pasadena, Calif., received nearly 90 million hits, said Kirk Goodall, the Mars Web engineer at JPL and manager of the Internet sites for the Mars Polar Lander. Also managing mirror sites were UCLA, the Planetary Society, Silicon Graphics Inc. and Excite Inc.

The current volume of Web traffic represents a tenfold increase in hits received by the site since Dec. 2 and is more than twice the number of hits received during the landing of Mars Pathfinder in 1997. Pathfinder landed July 4, 1997, and on July 8, NASA Web sites received a record 47 million hits, Goodall said.

"We had barely enough bandwidth just to vector people away from JPL," Goodall said. As a result, Goodall will include in his report to NASA headquarters a request for higher bandwidth in anticipation of more traffic during the next planned Mars landing in 2003.

"If [the Mars Polar Lander] had landed, there is no doubt in my mind this would have been the biggest Internet event in history," Goodall said. However, because NASA could not establish communications with the spacecraft, traffic dwindled to about 18 million hits Dec. 4, he said. More recent figures were not available.

NASA relied on a conservative mix of technology to handle the Internet traffic and redirect users to mirror sites, Goodall said. Sites that took advantage of newer technology, such as the Silicon Graphics and Excite pages, used virtual IP addressing that excluded viewers with older versions of Web browsers from accessing those sites, he said.

"When you plan for an event of this size, you have to cater to the lowest common denominator," Goodall said. With newer technology and software from Resonate Inc. that automatically redirects traffic to mirror sites before file requests reach the server, NASA will be able to better handle traffic in the future, he said.

NASA relied on two T-3 communications lines that provide 55 megabits/sec transmissions. That is not good enough now and will not be in three years, Goodall said. To handle the next event, Goodall said he needs an OC-12 line, which provides 655 megabits/sec of data transmission.