Houston, we have a social networking problem. NASA's digital gurus got a nasty, but brief, surprise Friday when a hacker broke into the agency's astronaut Twitter feed to peddle flat screen televisions.

The Internet incursion occurred on the @NASA_Astronauts feed, which redistributes official NASA Twitter posts from the space agency's web savvy astronauts who post messages about their missions from Earth and space.

"It appears our @NASA_Astronauts account may have been hacked," NASA spokesperson Stephanie Schierholz told SPACE.com.  "Five sales tweets were sent from the account."

Shierholz said NASA's Twitter overseers spotted the hacking in less than 15 minutes and immediately fought back.

"We closely monitor our, and once the issue was discovered?we took corrective action," she said.

All five interloping posts were aimed at advertising LCD or plasma flat screen televisions.

"Our apologies for the odd Twitter behavior earlier. We have fixed the problem," NASA posted on the @NASA_Astronauts feed. "Back to tweets from NASA astronauts."

NASA uses the microblogging website Twitter as an outreach tool to spread messages about its astronauts, space centers, and manned and robotic space missions. [Twin Astronauts on Twitter]

Last year, the space agency won a Shorty Award for the Twitter posts from its Mars Phoenix Lander mission, which landed a probe in the Martian arctic in May 2008.

NASA astronaut Mike Massimino, a veteran Hubble Space Telescope repairman, was the first spaceflyer to send Twitter updates from space as a way to share the experience of training and flying on the final mission to Hubble in May 2009.  Massimino posts as @Astro_Mike and, as of today, has 1,278,812 followers.

Earlier this year, NASA set up the first direct Internet for astronauts on the International Space Station, which allows the station crew to surf the web and post their Twitter updates directly from space (Massimino sent messages to Mission Control, which then posted them from Earth).

NASA astronaut Douglas Wheelock, who posts Twitter updates as @Astro_Wheels, is currently the chief Twitter astronaut on the space station. He arrived at the station last month and sends messages and photos to Earth via Twitter.

"Another breathtaking sunset?we get 16 of these each day in Earth orbit, each one a treasured moment.," Wheelock wrote in his latest post. "That beautiful thin blue line is what makes our home so special in the cosmos. Space is cool?but, the Earth is a raging explosion of life in a vast sea of darkness."