Summary

  • JPL’s June 1997 mirror list included Catlin Gabel School with a stated capacity of 500,000 hits a day and asked readers to choose a site near home.
  • Twenty mirrors later reported roughly 566 million requests from 1 July to 4 August. By 2004, NASA had made scalable offsite hosting part of its portal requirements.

Among the addresses NASA offered people hoping to see Mars was a school in Portland, Oregon.

In its 24 June 1997 announcement, JPL listed Catlin Gabel School as a mirror for the Mars Pathfinder website. Beside its address sat a capacity figure: 500,000 hits a day. JPL’s own listed mirror had a figure of one million.

An ambitious assignment for the school website.

The instructions were practical. During the 4 July landing and the rover’s initial seven-day mission, readers should use a mirror close to home. Around 20 were planned by the end of June. Research centres, companies and space agencies appeared on the same list.

The audience had a small job before settling down to admire the rocks: pick another place to fetch them.

An image needed somewhere to go on Earth

Webmaster David Dubov expected at least 25 million hits on landing day and a similar daily level during the following week. The site would offer mission updates and photographs from the surface as they became available. An operations-room camera at JPL already supplied a view refreshed every 15 minutes.

The mirrors provided additional places to serve those materials. In its 2 July announcement, San Diego Supercomputer Center described the arrangement from the receiving end: NASA would relay incoming data to SDSC and other high-capacity servers.

SDSC expected mainly visitors in the southwestern United States, though its site was accessible worldwide. Before landing, its shelves were already stocked with Hubble views of Mars, Viking images, scientist interviews and three-dimensional or virtual-reality tours. Teachers and families had an education page, too.

A mirror could give an impatient visitor something to explore while the next image was being prepared.

SDSC also mentioned the digital-format conversion involved in putting arriving pictures on the web. Between the spacecraft and someone’s browser lay a chain of receiving, preparing, copying and serving files. The public address list exposed the last choice in that chain.

The office felt the crowd

The mission’s 8 August report credited 20 mirrors with 565,902,373 hits from 1 July to 4 August. Its busiest reported day, 8 July, brought 47 million. The report named Kirk Goodall as the web engineer who constructed the mirror network and Dubov as its manager.

These were requests for files and page elements: loading text and pictures could register several hits during one visit. NASA’s later explanation of the unit spells out that counting method.

The enthusiasm also reached less glamorous corners of the agency. In a twentieth-anniversary account, NASA Internet Services Manager Brian Dunbar recalled that Headquarters’ web traffic shared an indirect connection with its business services. Email and other office operations became very slow on 7 July.

The people looking at Mars and the people trying to get through their inboxes could therefore compete for the same stretch of network. The address of a public website was also a decision about where a crowd would arrive.

Catlin Gabel School’s place in the list made that decision unusually visible. NASA supplied the mission material; another institution offered a place to fetch a copy. Getting a Mars photograph home involved some decidedly terrestrial directions.