When the space shuttle Discovery was launched into Earth orbit Tuesday morning for a 12-day mission, more than 335,000 simultaneous video streams broadcast the event live to Internet viewers, making it NASA"s most-watched online event of the Internet age.

The live feeds were provided through a first-ever deal between NASA and Yahoo Inc., which is offering real-time NASA video of the mission on its Web site. The feeds are also available through NASA"s own Web site.

In an announcement Wednesday, Sunnyvale, Calif.-based Yahoo said the 335,000 simultaneous video streams were triple the previous largest audience for a NASA mission. That occurred on July 4, when 118,000 webcast streams of the Deep Impact comet research mission were delivered online. In January 2004, NASA had fewer than 50,000 video streams for the Mars Exploration Rover landing, according to Yahoo.

This is the first shuttle mission since the Columbia disaster in February 2003, in which seven astronauts were killed when the spacecraft broke up on re-entry.

Enterprise Web hosting vendor VeriCenter Inc., which hosts NASA"s Web sites, recently bolstered its infrastructure to meet viewer demand during the shuttle mission, while Web content provider Akamai Technologies Inc. is streaming NASA TV video feeds for users of Real Networks Inc."s RealPlayer media player.

Akamai is also delivering all other Web content to NASA"s Web sites during the mission.