In another milestone for Internet video, nearly 433,000 people simultaneously watched NASA's webcast of this week's space shuttle launch.

That's more than twice the 175,000 streams that America Online Inc. had at its peak July 2 for the Live 8 concerts (search), an event widely cited as a coming-of-age moment for online video. It also nearly quadrupled a record for NASA set three weeks ago during Deep Impact's (search) encounter with the comet Tempel 1.

Yahoo Inc. (YHOO), in a partnership with NASA, sent out 335,000 streams in Windows Media format, while Akamai Technologies Inc. (AKAM) sent the rest in RealMedia format.

Space Shuttle Discovery (search) lifted off at 10:39 a.m. EDT Tuesday, when many Americans were at work and had no television access.

Scott Moore, Yahoo's vice president for content operations, acknowledged that the online audience would have been lower had the launch occurred over the weekend or at night.

"Watching streaming video on the computer today is still not the same quality experience as watching the same broadcast on television, but if your choice is to wait until you get home at night versus pointing your browser that's on your desk at work, ... then it's sort of a different choice," Moore said.

Other companies also webcast the launch, but unofficially. Moore said the audience may have exceeded 500,000 if those outlets are counted.