Kennedy Space Center, Florida (CNN) - On the morning of the launch of the space shuttle Endeavour, Lloyd Behrendt paced the floor of NASA's news center at the Kennedy Space Center, rubbing elbows with reporters while keeping an eye on the countdown clock.

Behrendt wore a baseball hat adorned with pins from previous shuttle missions. His media credential dangled from his neck. A camera strap was slung over one shoulder.

But he doesn't take photographs for a major publication, nor does he report for a television station, newspaper or radio network. Behrendt is a member of a close-knit group of people that some call space junkies.